As an avionics engineer for 31 years, I am absolutely appalled that the MCAS system depended upon a single Alpha Vane sensor. All flight critical systems must be dual redundant in function. In a 21st Century designed aircraft this is inexcusable. There are NO EXCEPTIONS TO THIS RULE.
Chances1957 - I am also appalled that the design doesn't provide for a feedback loop from the current stabilizer position to the MCAS so that this bit about repeated and cumulative movement of the horizontal stabilizer can be better controlled. That is, if the stabilizer is already moved to a 3 degree nose-down correction due to the first MCAS activation, the MCAS should be aware of that before any attempt to move the stabilizer further, especially if there are signs that the crew is fighting the MCAS.
WakeUpAmerican000s I absolutely agree with your comment. Certainly as a design engineer I would have implemented your suggestion otherwise you will arrive at the situation we have witnessed. Thanks!
Dmitri Kozlowsky MCAS May be dependent upon TWO sensors after the recent modifications, but it was only dependent on one sensor at the time of the two crashes!
Hey Petter, as a Verification Engineer of Embedded systems. I simply cannot fathom, how the guys who tested/verified the MCAS system did not ask the question, what will happen if we have a mismatch in the alpha veins or if 1 or both pilots are applying manual counter trim... or if the trim wheels are held with X speed that they are supposed to... In my line of work, we always ask ourself, what will happen if such an input misbehaves. I cannot fathom what the Engineers that tested and missed this are feeling. People died... if I was working on the MCAS... thank god I am not.
@@Joaking91 You are wrong... our job is to verify the system. Yes we don't design it, or don't set the requirements... but we always ask the questions... why is this like that, what if, how is this etc. From those questions often the guys designing it get a second opinion and they rethink it. P.S. As a good verifier I am always questioning everything. Even if a detailed specification is written, explaining everything. It is written by a human. There is bound to be an error or misunderstanding somewhere. So is every piece of code I work on. You never know how much code is legacy from a previous system. How much of it is new. What quality it is. Etc ...
I think your giving Boeing way too much credit. 2 of the main aeronautical engineers who were principle designers of the 737 MAX since have walked away from Boeing over safety concerns over the airplanes air worthiness...On top of that.. There is an American Airlines Senior Captain of their 737 MAX Fleet is on T.V. saying he no longer supports Boeing and had a meeting with top executives at Boeing along with the Pilots Union here in the U.S. and raked Boeing over the coals and insinuated a huge betrayel by Boeing to the Pilots and the flying community. I would really like to hear you comment on this please. Thank You
*> They are paying a price that they well deserve to pay.* No, 384 souls paid the price. The rich execs don't pay ANY price unless their wives and kids die screaming and crying when their airplane falls out of the sky.
As I said in a previous video on this MCAS system, there should always be dual redundancy in critical systems on aircraft. There are no exceptions to the rule - NONE!
Control column inputs? They should only be recognized if both pilots are giving identical inputs simultaneously? It could be argued that it might have saved AF447, but it still sounds like an important exception! :-)
@@ReflectedMiles Using two Alpha Vane inputs instead of relying on a single sensor is what I meant by making a system "dual redundant". The planned changes to the software will now require the use of both sensor inputs unless their respective readings differ by more than 5 degrees. Logical!
Chances1957 I understood your reference. I was just pointing out that one exception to redundancy is in the most important sensor inputs of all to the system-control manipulation by one pilot, not requiring two pilots to attempt control of the aircraft at the same time.
@@ReflectedMiles What's the analogy here? A pilot who goes nuts, or a control column malfunction? Pilots can watch each other, both can realize there's something going wrong with one control column and decide to use the other. The pilots are already the system checking that the control column is working, and that each other (humans) are working and acting properly. Similar mechanisms were missing in the MCAS.
Mentour: I am a big fan of your YT channel, but I have to say that in this video, you really sounded like a Boeing apologist. I understand everyone has biases and you realy love flying your 'Baby' the 737, but I think even you could admit that Boeing made a mistake. Anyway, keep up the good work.
Yes, that‘s my opinion, too. - Boeing knew how to do MCAS correctly, but they did not in the 737MAX - They used 1 sensor for a flight critical system which is not allowed in civil aircrafts - Boeing did not include MCAS in the iPad training, although it changed the behaviour of the plane like NEVER before - Boeing did inform the FAA in a wrong way about how much the MCAS can interfere So overall, the reason for all this seems to be to avoid that the authorities order a simulator training. Which would have made buying this plane more expensive. And Boeing would have lost more orders to the better A320. Overall Boeing deliberately (!) cut short on quality. There is NO excuse for this. It is always possible for engineers to make an mistake. This was no mistake. It was deliberate action to only use 1 sensor and not mention the all new system in the training. Mentour: I find it strange that in the video that fact that 2 planes crashed is not taken into consideration when talking about if Boeing did well and if that plane is safe to fly. One could think you talk about the theoretical case that something with MCAS could go wrong. It went terribly wrong. Boeing will have to pay for this in several ways. Because it was no a „fault“, it was a „fraud“.
No, I don‘t. I‘m an engineer in healthcare. If our company would know about a SW error that could kill or just even hurt hundreds of patients again (!) anytime, we would stop our systems to be used by customers immediately. If we wouldn‘t our company would be closed by the FDA and the EU authorities and someone would end up in jail. Safety critical sub-systems/interfaces/... need to be made error prone TWICE in our business according to regulations. That‘s exactly what Boeing didn‘t do, although this is done for life critical systems in planes, too - normally ;-)
@@drock5407 He is a realist. I fully agree with him. Boeing screwed it utterly and completely, and I am very confident that criminal charges can and will be brought against them, and it will be succesful, unless they can evade it due to jurisdictional issues. The only unfortunate thing I see here that Boeing did not crash in the USA... Prosecuting them would be much easier.
You are absolutely right, Mentour sounded like PR person for Boeing. He said plane would be thoroughly tested by FAA and other agencies to make sure it is completely safe for you and me! Yeah, wasn't it 'thoroughly tested' to be licensed and yet we are here. They certainly knew this is flawed plane and they didn't even tell the pilots about MCAS, which was also flawed, but they still sold and delivered it, and now 350 people are dead. If this is not a shady business, to avoid using stronger but more realistic word, I don't know what is.
Considering AOA indicators as "optional" based on your prior experience with AOA sensor/indicators is irrelevant when it comes to the 737-MAX because the critical MCAS system as (fatally) designed depended on those AOA sensors.
true, but a bad aoa sensor mcas can be turned off. You can easily still fly manually and trim yourself without any MCAS. Maybe boeing put too much faith in pilots diagnosing and handling bad sensors. Its not really a design flaw, but humans getting confused is a tough thing to design for.
@Wild West that is not really the situation. There is no "just turn off the MCAS and continue as usual"! You can cut out the trim motors but that does not disable only MCAS, it disables ALL automatic and power-assisted trim. (ok there are 2 switches, but not a separate one for MCAS only) So there is no "easily still fly manually". You will have to turn the wheels by hand and you can see in the other video that that is not easy. Remember you not only have to revert the change made by MCAS but also have to perform all other trimming up to the landing.
@@wildwest1832 Worse than a design flaw, Boeing likely committed a criminal act when for commercial reasons they wanted the new 737 version to handle like the old ones. But changes in the new version required an additional system to handle certain flight situations. The development of that system and the safety analysis of its implications were rushed through. Pilots were not informed of it and not trained to counter its failure.
So, instead of copying the MCAS from the military version that works well (uses two sensors, turns itself off if the sensors disagree, turns itself off if the pilot tries to move the nose up), Boeing made a civilian version of the system with one sensor and more difficult to turn off. Even though the aircraft had two sensors anyway, so it's not like Boeing saved money by not installing one of the sensors. This looks to me like the software job was given to an intern or a new employee as a first assignment and it was made very simple - if sensor says AoA is too high (and flaps up, thrust high, autopilot off), trim the nose down, unless the pilot disconnects the trim motors. But yea, the 737MAX is probably going to be the safest airplane after this. If there is another crash due to a design problem (problem with the fix or an unrelated problem), that would be really bad for Boeing, so I think that the whole design will be checked.
I really get the bad design part of the story (reading how the MCAS works made me ask myself “isn't this a rookie mistake?”). What I don't get is how was it possible that the pilots of the second crash didn't know. I mean, you pilot an aircraft and you know there was a crash of the same model and some speculation on the reasons of the crash was already out there and the MCAS is mentioned and explained. How come they didn't think of the stab trim cutoff?
@@WilliamJones-Halibut-vq1fs From what I read about the "new math" crap (where 3*5 is not the same as 5*3) and forcing the students to strictly follow procedure instead of thinking, then I'd say at least that part is not so great.
@@WilliamJones-Halibut-vq1fs. American baseball teams are all best in the World Series though. Can we assume this study was carried out by alt right Americans.
Finally a voice of reason and expertise on TH-cam. There are so many people eager to jump on the lets bash Boeing bandwagon who hardly know one end of an airplane from the other. Keep up the good work. I found your explanations clear, concise, and accurate. I am long retired, but have logged around 25,000 hours in Boeing 727, 757, & 767 aircraft, and am amazed at the rush to judgment of so many uninformed people. .
Making a system that can fly the plane into the ground based on one erroneous sensor is negligent, but the worst aspect was keeping pilots in the dark as to the existence of this system. They should have been briefed on it and trained in a sim to recognize the angle of attack sensor failure and practice dealing with it. If every MAX pilot had done this it would be much more likely the crews would react in the right way instead of flying into the ground struggling to understand what's going on while consulting a manual that doesn't list the MCAS system's existence. From what I can see pilots were kept in the dark precisely to avoid the need for expensive sim training. And so it's probably management at Boeing and the airlines that, while not directly responsible for the disasters, they did set up the conditions which led to it. And every one of us who chooses an airline ticket based on price has contributed to those conditions being set up. In the end, there is a certain minimum cost associated with doing things properly.
I flew these aircraft from mar to jun. They were fine but I had my heart in my mouth praying nothing would go wrong. AA uses 737s a lot and loads of people were boarding them. In Some cases you can't choose other brands. The destination is only accommodated by 737s. So you're stuck with it. I tried the train to Fresno . 4 days solid. Bus same thing. Just saying.enjoy the flight. ù can't take a boat.
MCAS exists to "save" the plane from stalling when the pilot goes full thrust and pitch up, aka to prevent an unrecoverable stall. However now Boeing has added all these defeats to MCAS it is not likely to actually trigger when it SHOULD. So instead of having the plane crash because the MCAS is forcing nose down into the ground, we accept the risks of having the plane stall out in a climb. All of this goes back to: "Is it a good idea to take a design from 1967, patch on giant engines that require pontoons to move these behemoths forwards and up (and extend the front landing gear) so they dont scrape the runway, and then patch all the flight problems that result" --- INSTEAD of: actually designing a plane which is balanced for these engines in the first place, further back under the wing, with taller landing gear all round, and the right amount of fuselage ahead of the wings. All in the name of profit.
Agree with you 100%. Explains why none of the other Boeing aircraft needs MCAS. Sad thing is they will issue "software fix" and say "have a nice flight." We all know it's not a properly designed and balanced plane for those new engines. It will always be a "dog" to fly with pitch up tendency. They have a chance to fix it now. As you say longer landing gear, move the engines where they should be, modify the wings and generally do a proper fix by balancing the plane better for the new engines.
@@manaoharsam4211 MCAS is the evidence that there is some issue at high thrust and high ANU. Airplane weight may also be a factor in this. Such as (either) takeoff (high weight due to having more fuel at start of flight) or more likely during a go-around (an aborted landing of an aircraft that is on final approach) (low weight aircraft).
I agree with you. I find there were a lot of arrogant Engineers at Boeing when I worked there. Also management knew nothing about planes. Just bean counters. when I worked in area of aero elastic instability not one Engineer had a clear knowledge of subject. They were push computer button Engineers. In fact when I went to a professor class I could tell the skill level was very poor of students from all walks and companies . I told everybody be at Airbus or Boeing I am scared to get up on a plane. When companies pay you good I money my approach is do the best job of learning even on your own time in order to do correctly. This is fun work. Some Engineers I worked with they prefer fishing than aerospace. I say leave then.
I believe that Mentour explained what needed to be said and understood by the flying public and those that are interested in aviation... I believe that those in the media were not capable of explaining in layman's terms what Mentor said very clearly and jumped to conclusions without understanding how planes fly and how pilots fly them.!!!
There was a very similar circumstance of a safety feature the pilots didn't know about causing an accident with SAS 751. It was a DC-9 (MD-81) and SAS had fitted ATR - Automatic Thrust Restoration - to prevent pilots throttling back too much for noise abatement reasons. As 751 took off, ice came off the wings into the engines, damaging them, the pilots throttled back but the ATR (which they hadn't been told about) overrode them with full climb power, which caused the engines to fail completely shortly after at 3000 feet. They were incredibly lucky and managed to crash-land in a field with no fatalities.
That was an excellent update. But Boeing needs to have an independent organization do some serious investigation as to how these very poor design decisions were approved and tested. It appears to be gross negligence. They are going to be sued, there is no doubt about that.
@@kradius2169 My understanding is that procedures were followed on that and resulted in a NTF on a return to service test after landing. Likely the NTF was caused as MCAS alternates on which AOA to use in each flight segment. So it had cycled to the good one after landing and the ground test then checked the good one. Then the next flight it had cycled back to the bad one and crashed. That is just a test procedure problem that is easy to correct, a little late though. But will be changed anyone since update uses both AOAs.
@@kradius2169 They probably don't have recorder data for that event, but I thought they determined through crew interview they pulled the power to the electric trim. In the crashes, they didn't have enough altitude or experience to figure that out. The recorders from both crashes should indicate that is why pilots could not recover.
Billy ... Not enough altitude? I thought the Lyin' Air doomed "pilots" struggled with the plane, fighting valiantly against the flawed Boeing MCAS system, for minutes? How long would you struggle with the cruise control on your car before you tapped the brake or hit the switch? ... Minutes? _
Your answers are not convincing to the controversy of Max8. The MCAS and MAX handling turned out to be an engineering disaster of Boeing and a big shame of FAA certifications. But from your comments, it seems that nothing is serious.
Henry Delana the audience would like to understand what caused the two accidents from a technical perspective. Unfortunately from the video I could not find much reasonable doubt for potential flaws from the point view of aerodynamics, S&C, flight control or fly-by-wire.
I want to accept your endorsement of the 737 Max, however I just don’t believe that Boeing has actually come to identify the problem. Their unwillingness to ground them after the Ethiopian crash demonstrates their intransigence.
Boeing identified the problem and started working on fix in 2018. The fix required that they get FAA review. Donald Trump shut down the US government in December. No FAA employee could assist in getting the fix approved while Trump refused to budge. The FAA is culpable, as is the Department of Transportation and it's Secretary who is the wife of Mitch McConnell. If you wish to inform those who are responsible for the Ethiopian accident do please include Elaine Chou (Secretary of Transportation), Mitch McConnell (who refused to halt the government shutdown), and of course Donald Trump whose shutdown materially interfered with the solution that could have saved lives. Please note the use of the term "materially interfered".
Having identified the problem and then, after the second accident, claiming that nothing is wrong and the plane is safe to fly, only makes the matter worse for Boeing.
@Röhrich Oak It is unfortunate, but there is a lot of history behind what has happened recently. The US FAA has been encouraged by the US Government to hand over regulatory responsibility for airplane certification to the companies involved. The implication was reduced budgets for certification. The FAA caved, and the US Government cut their budget (which had to have the approval of the Secretary of Transportation, a Presidential appointee). This was not Trumps doing. Think of the last Republican President who proposed spinning Social Security out to the private sector prior to the Great Recession (that his economic "let the banks do what they want to do" created). That former Republican President is safe from harm in Texas. Meanwhile Boeing chose to finesse a training dodge that would assist sales. The dodge backfired with the Lion Air accident. With certification already in place Boeing was forced to propose a solution that required FAA certification. The current Republican Administration shut the FAA down for other than "mission critical" functions. The current Secretary of Transportation could have challenged the situation by stating that the FAA team working with Boeing needed to stay on the job so as to prevent another accident. If that protest was made it was kept very quiet. Her husband was assisting the President in holding the FAA hostage. This is not to say that Boeing is not most at fault. Boeing stuck to the "no simulator training required" mantra that their Vice President had pressed to Muilenburg as an important hook for sales. Muilenburg was also getting briefings from legal side of the issue. Any admission of guilt would be used in lawsuits which were sure to come. The Legal Department knew their only best choice was to negotiate settlement out of court. Their worst fear was a class action. So now you know what Muilenburg is dealing with. His sales-oriented solution was blocked by a Republican Administration's obsession with holding the government hostage for whatever reason. The Legal Department told him if you ground the aircraft it will be an admission of guilt. To some it may seem ironic that a Company who gained sole control of the US commercial airplane market could find themselves in such a predicament. A competent manager would never have accepted the Engineering decision to use a single-point-of-failure solution that could put the plane in peril. A competent manager would not have accepted the Sales suggestion that training for the single-point-of-failure was not required. A competent manager does not run the Boeing Corporation. In order to gain the industry's trust Boeing's Board will have to show that the Boeing Company is better than it has shown itself to be recently. They can start by firing the CEO.
Mentour, your videos make everything much clearer. Your approach to whatever the subject matter is never feels like you are forcing your personal opinion down everyone’s throats. You give factual and very straightforward information based on what has been documented by the various aviation authorities. Some other YT aviation gurus feel that they need to use brute force to drill the subject matters into our heads. I’ve personally found that you teach very well and I hope that you will be recognized for doing a video in the correct manner. As an aside, we can also get to see your hairy kids as well showing that you are human and don’t consider yourself to be at a level above your audience. Great job as always.
Hah, at 0:48 shows MAX flying almost vertically with zero problems. A couple of other pilots had the same problem and just turned the system off...a couple others just crashed the plane. Shawn White can jump a snowboard, but I can't...should we blame the snowboard?
I thought that was a flight test? With zero passengers and flown by Boeing pilots who probably are a lot more familiar with the system. You really can't blame the pilots for the ill fated Lion and Ethiopian planes. My friend is a pilot for Delta and has said many pilots are disappointed with Boeing.
Drew P Knutz My thought exactly! The 737 MAX was successfully flown over 41,000 times for over 120,000 hours delivering over 6.5 million passengers but now it is the most dangerous machine ever invented and Boeing delights in killing their customers!
They will make it right only for their profits which might be compromised as a result. They thought they'd get away with it, but not after the second one went down. Sociopathic Dennis Muilenburg didn't end up out of pocket.
Questions I'm hoping the FAA will be asking in addition to the standard ones. 1) Why did those sensors fail? Is there a flaw in the design or manufacture? How often do these sensors fail? 2) Are there any other systems on this aircraft that rely on a single input - critical or not? 3) Is MCAS integrated into the flight control computers or a separate system - if it is separate is it possible for the pilot or first officer to disable or reset MCAS?
I would add 4) Are there any other systems, functions and or alarms that would have activated or de-activated as a result of that sensor fault that would have contributed to these accidents, apart from MCAS?
As a MAX driver myself, what about the stab cutout switches and fly the plane first. There’s been no mention in the press that Lion air had the same problem the day before and they used trim cutout switches, manual trim. Easy to say since I do have the advantage to Monday morning quarter the situation.
Dane ... Holy crap. Like you're the only person so far today & most days lately that I've come across that seems to be aware of the MAGA / free press Juicy Smellitt schwindle being perpetrated against Boeing. Not a single member of the bloodthirsty Boeing carve-up mob that I've challenged knows about the PAN-PAN call the day before the doomed Lyin' Air 737 MAX took a swim ... not to mention the unchanged since Day 1 in 1967 and likely to remain unchanged till 2067 process for a 737 pilot to actually start flying their plane. _
I see the lack of AOA sensor redundancy as a severe design flaw, especially since the second AOA sensor was installed, anyway. To keep knowledge of the MCAS system from the pilots just to reduce conversion training costs, however, verges on being criminal negligence.
The criticality of the system was high enough that it should have required redundancy by FAA policy per the Seattle Times report. How it does not have redundancy and still got approved is apparently not yet available. I suspect the FAA and DoJ are looking at that pretty hard.
Boeing provided data from NG flights that demonstrated the required performance for prevention of engine-driven pitch up. Since the FAA had no responsible representatives present at Boeing they accepted the data as proof of performance for the augmentation required for the new engines. Only Boeing and the FAA know why Boeing's proposal to use only one AoA sensor for what was to become MCAS was accepted as sufficient. We know why Boeing did it. It was all about the "less than an hour train for the new certification" sales pitch. It takes a very strong CEO to face the facts and say NO.
@@henrydelana9317 Speaking of CEOs, the one from Ethiopia Airlines ought to have his tail set on fire. He allowed a 200-hour pilot to sit in the right seat. That's no better than having a single pilot in the left seat and one of the passengers from the back sitting in the right seat who just got his private pilot's license. As Capt. Sully said: "It's abhorrent" to have a 200-hour pilot as a crew member. The CEO was trying to save money by getting young eager guys to build hours at the expense of the 180 people who died due to lack of education. The fact that the prior evening flight crew experienced the same problem but didn't advise the following crew really burns me up. Luckily, the crew the night before had a pilot sitting in the jump seat who knew about the two trim cutoff switches. Otherwise, the disaster would have happened a day earlier.
@@daffidavit, you are confusing the Ethiopian and the Lion Air crashes. The Lion Air aircraft had the same problem on the previous flight, spotted and solved by the jump seat pilot. The problem WAS written up and the AOA sensor replaced before the fatal flight, so the failure was most likely in either the wiring or the computer input channel. At this stage in the B737 Max saga, few pilots knew about the MCAS system as it was not included in the conversion training. The Ethiopian 200hr pilot: In the past, it has not been uncommon during pilot shortages to hire pilots with the ink on their CPL licences still wet. This may be rare among major carriers, but this is simply a matter of company policy, which is usually changed to suit the new pilot supply situation, and has been true around the world. There is no indication that this low aexperience had any bearing on the accident, in fact this pilot must have just come out of the rather intensive initial type training on a regular B737 flight simulator, so he was most likely quite competent.
@@Halli50 Thank you. I did confuse the Lion Air flight, so I have to take it back about the failure to advise the next crew on the Ethiopian flight. But I still agree with Capt. Sully, it was "abhorrent" to put a pilot with only 200 hours of flight experience in the right seat. I don't blame the pilot. Any young guy would jump at the chance to be a first officer in a 737 MAX. But the CEO should be held accountable for not training the Captain on the MCAS system, especially since it was known from the Lion Air incident and other NASA voluntary pilot reports that the trim could go into a runaway situation. Finally, the Colgan air disaster near Boston taught us that flight experience can mean the difference between life and death. When there are many people sitting in the back seats, they expect and deserve the best. After the Colgan disaster, Congress made the FAA change its regulations to require all major airline pilots to have at least 1,500 hours. The Captain must have an ATP rating. And if the captain is over a certain age, the pilot in the right seat must also have an ATP. I respectfully disagree with you about a 200-hour pilot coming out of 737 sim training being competent. As Capt. Sully said the crew must act as one. They have to be able to almost read each other's minds and act accordingly when there is an emergency. No 200-hour pilot is that good. The passengers deserved the best pilots not, as Sully said, one pilot and an apprentice. Thank you for correcting me..
Don't be so insulting. Civilian and military pilots are both fully aware of AoA. Stop apologising for Boeing too Also you assume MCAS gets bad data from the AoA sensor, but all indications are that MCAS actually misreads data and then goes on it's merry way. Every 15 seconds. Boeing would absolutely love this thing to just be an AoA sensor problem...but it isn't...
well: a flight incident is never "just a technical problem". It is a rabbit hole with many contributing factors. Who approved a system that: Relies on just one sensor? Why does it not cross check with other sensor types? (Attitude indicator, Air speed, ...) Who authorized such strong control inputs by MCAS? For the intended function and situation a few degrees would have been enough. Why did maintenance not realize that the AoA sensor was defective? Why where the pilots unable to find the relevant checklist item? Is the checklist not structured correctly? Is the manual missing information? Is the training inadequate? Should the 737Max have been the same type as the other 737?
@@iBreakAnkles4Fun Runaway trim is a memory item. You are supposed to know what to do without a checklist. I. Runaway Stabilizer CONTROL COLUMN - HOLD FIRMLY AUTOPILOT (if engaged) - DISENGAGE Do not re-engage the autopilot. Control airplane pitch attitude manually with control column and main electric trim as needed If the Runaway Continues STAB TRIM CUTOUT SWITCHES (both) - CUTOUT If the Runaway Continues STABILIZER TRIM WHEEL - GRASP and HOLD
Boeing's corner cutting gambit has cost lives. The engineers will be fired, and the executives will get bonuses for steering the ship during difficult times. Even though the decision to reengine the 737 was made by the c-levels to change the 737 flight characteristics using a bigger diameter turbofan and then cut costs by insisting that no retraining was necessary.
First question, your response is only partially correct. The AOA display may not be necessary for safety but the disagree indicator is necessary for safety. If you had this indicator before the software upgrade it could have told you to disable the Auto Trim before your plane took a nose dive. Even in the event of emergency the warning light could have pointed you in the right direction to disable the system sooner. Especially if Boeing had told you about the MCAS system and had a procedure that directly told you to disable the electric auto trim if this indicator is on. If they had told the pilots about this system and had a procedure for it many lives could have been saved.
If you are a pilot and have to have an indicator light to know when the trim is running against your input on the yoke, I have zero interest in flying with you. Boeing had warned the Ethiopian pilots about MCAS and reminded them of procedures. Maybe you're right--maybe they needed an indicator. Are you sure you want to go there?
If the 737 max is a very stable AC ,as you are stating , then why did they have to install a MCAS function on this version of 737 ? I can imagine this scenario in 2011, when Airbus was launching a new AC that would take some major market out of Boeing. Boeing had to react super fast to keep their market share, so management probably put huge pressure on their advance design team to come up with a quick solution. A complete new AC would of taken to much time so they decided to tweak this low landing gear AC design, with the biggest engine bypass ratio , in order to compete with the Airbus Neo fuel economy. To keep the engine ground clearance they had to move the engine forward and raise the forward landing gear (it was not possible to raise the main landing gear without a major redesign of wing that would of require a new AC certification which would of taken more time to market ) . This and the much larger engine nacelle create a condition at high AOA were the nacelle provide unwanted lift that can tiger a positive feedback looping and stall the aircraft in the most critical part of their flight plan. I am not a pilot but I dont think that with a max loaded aircraft in climb it is possible to recover from a stall. The failure of the FAA to scrutanise Boeing and prevent them from taking shortcut to beat their competition , is IMHO the cause of these two AC catastrophe . The US corperations controled the governement into eroding the authority and understaffing the FAA so they can have a clear path to profits. They also control the MSM and I can't help to wonder if , with all the money which is at staked here , that you are not being compromised in your evaluation of the safety this 737 max. I am very pessimistic about the future ,because other goverment watch dog agencies like the EPA and FDA and Atomic energy may be in the same situation as the FAA and could result in much bigger catastrophe the those two crash.
There are three broad types of (in)stability: 1. Positive stability where every disturbance returns to the previous (normal) position. 2. Neutral stability where a disturbance remains in the last position. 3. Instability where a small disturbance rapidly accelerates into a runaway condition. The B737 (along with all passenger aircraft) stays within positive stability in all phases of flight. MCAS is only designed to deal with a small deviation from the acceptable rate at which the aircraft returns to the previous (normal) condition. This is a certification requirement regarding the feel of the pilot controls in manual flight, and was never related to (in)stability. The answer you describe is melodramatic journalistic shorthand for a much more subtle concept. The rest of your comments are incorrect.
@@buffdelcampo Obviously, you can't do anything for the people killed by the accident, and I am a big fan of this channel, but I do think Mentour could express a little more gravity. It's not like an iPhone update that Boeing is releasing -- this likely caused two crashes, and after the first one, they were already working on the fix while allowing their aircraft to fly. They were also apparently allowed to self-certify the safety of these aircraft by the FAA, and I think there should be some outrage expressed. How can he say that he thinks it's one of the safest airplanes in the sky if the certification process is flawed? I heard on the news that the FAA can't afford to hire the necessary people to do the safety certifications, so they allow Boeing to do it themselves, which obviously has a conflict of interest. It's more than just a "PR Nightmare". The sad part is that the grounding of all these planes is costing the airlines (and Boeing) tons of money, so there will probably be a rush to lift the ban on the 737 Max. There's so much pressure to have a hasty update that could still have problems, and the full accident investigations may not even be complete.
@@gfuterfas Instead of watching the idiots on the news, dig into this. Do some real research. Most major manufacturers self certify. It's been that way for at least thirty years. So how many airliner designs are self certified? Probably all.
@@ericbedenbaugh7085 - the Ethiopian crew did follow procedures after three cycles of incremental (and un-wanted) stabilizer movements initiated by the MCAS. The crew turned off both switches to remove power from the horiz stabilizer motor, then attempted to manually change the stabilizer position by using the control wheel in the cockpit, as documented in Boeing's procedures following the Lyon Air crash. Current hypothesis is that because they were also honking back on the stick in an attempt to raise the nose of the aircraft, the limited mechanical advantage of the small stabilizer control wheel in the cockpit used to move the stabilizer was not enough to overcome the extreme forces on the stabilizer of the aircraft which was now exceeding the design limit of airspeed as it dove toward the ground. The crew realized that the frozen control wheel meant a certain crash, so they re-powered the stabilizer control motors, and attempted to use the thumb switches to correct the horizontal stabilizer position, but by then, it was too late. Boeing is in deep doo-doo with this woefully poor design because: 1) dependent on a single point of failure (one AOA sensor) for a critical response (nose-down correction, even at low altitudes) 2) no diagnostic checking of AOA sensor function visible to pilots on aircraft without the optional package to do so (which clearly says that Boeing realized this was necessary, but decided for some really strange reason to charge extra for it) 3) No feedback loop between Horizontal Stabilizer and MCAS - so no matter how 'smart' the MCAS software is, it couldn't tell that the Horizontal Stabilizer was already moved to a dangerous nose-down position before moving it further 4) inadequate manual backup for pilots to move the horizontal stabilizer under several flight conditions (something well known since the 70's - pilots used to be trained for this, but for some reason are no longer trained for it) 5) the "emergency" cut-off switches should provide the option to just turn off MCAS, and not the entire power to horizontal stabilizer motor, so that the pilot can make corrections to the stabilizer position using the thumb-switches provided for that purpose. Older models of the 737 had this - one of the two switches would disable auto-control functions but leave the power to the stabilizer motors "on". Why that option was removed on the MAX will no-doubt be discussed at some length in upcoming lawsuits.
You appear to accept what Ethiopian is saying. If this came from the NTSB, or the BEA, or the AAIB you should consider it as well thought out. It may not be fact (many air accidents are never truly understood, M370 being a classic example). Do not assume that an airline operating a plane that suffers an accident that claims the lives of all souls on board can be trusted to tell the truth about what happened. Ethiopian will have to demonstrate that it's pilots were properly briefed on the MCAS after the FAA directive went out in 2018. There are good sources of information about what is going on. You should seek them out.
That was HAL9000 taking action on it's own lol xD JK, yes the preliminary report are out, and the investigators said that the pilot already followed Boeing AD procedures, but still can't help them out of dangerous situation leading to the doomed flight, this should put to rest Pilot lacks of training as well, since they were aware of the MCAS after Lion Air, they also have been noticed about how to deal with it by following the trim cutoff procedures involving MCAS runaway. Idk about others..but if the Pilot did knew about what caused the nose down then followed by the correct procedures on how to dealing with it based on the manufacturer checklist but still can't save them out of the dangerous situation, to me the blame isn't on the pilots..it's something else...
Gordon Richardson -According to reports the pilots switched off the “Anti -Stall”system 4 times in 6 min.but the system turned on every single time.Here:”Ethiopian authorities, in a press conference Thursday disclosing findings from their preliminary crash probe, stopped short of drawing any firm conclusions about the causes of the crash. But they confirmed a flight-control system triggered repetitively during the six-minute flight, pushing the nose down. They recommended Boeing review the system, and said regulators should then test it before lifting a global grounding of the MAX fleet.”
What I found revealing in your previous mcas video is that after cutting out the stab trim motor, it takes a great effort to manually turn the trim wheel. Imagine being in an extreme pitch down position, with the pilot needing to pull back on the yoke with great force to counter the trim, it seems difficult to manually trim back within the short time allotted before zero altitude. Add to that the alarms blaring, potentially lessened situational awareness with the pilot monitoring pouring through the manual to find the resolution, i dont see how they can recover the stab trim manually at such low altitude.
You are very right! It takes two people on the flight deck who can exert strength when required. In at least one case that required strength when the plane was inverted. The Alaska Airlines jet crashed when it's stabilizer failed. All perished.
@@henrydelana9317 The Alaska Airlines crash was due to poor maintenance on the Alaska's part to cut cost. The jack screw was actually stripped of its threads because they were not greased at intervals that McDonald Douglas put in their manuals. Also, a Alaska mechanic put in for the jack screw to be replaced, and was overruled by his supervisor on his next shift. So no manual use of the trim system would have made any difference in the Super 80 crash. That was improper maintenance of the jack screw that lead to it's failure, and the crash.
The cutout switches are for when the electric assist is unreliable. It's a misapplication that it is the go to solution for automation logic fault when the physical assist functions just fine. It would be like if there was an ABS logic fault in your car the fix would be to disable the vacuum brake assist. Transparently-operating automation should fail safe and not require disabling powered assist.
@@towerrunner496 Hi Tower. Yes you are correct on all points. Did you read the transcripts of the cockpit voice recorder (CVR)? If you did you would have heard the pilot flying coaching the pilot monitoring on a last attempt to flip the plane over prior to impact. Had it worked he might have saved some lives. Unfortunately the pilot monitoring could not reach the rudder pedals while inverted. He was unable to assist in the rollover maneuver that the captain wanted to try. The captain was firmly belted in and able to work the rudder pedals. The first officer couldn't help. Perhaps my choice of a physically challenging experience eluded some. Do you know the name of the Vice President for Maintenance who was fired for this accident? Was you wife and daughter present when the CEO went to Fairbanks for the funeral of a man I knew?
I like your content. I was hoping you would address the question of whether or not there is ultimately a fatal flaw in the 737 MAX design from putting engines that are too large on an airframe that was designed for smaller engines. It has been suggested in articles about the unfortunate crashes that the MCAS system was meant to rectify an aerodynamic design instability created by the positioning of the larger engines.
Bingo!! if a software fix is needed to correct an aerodynamic error the aircraft is unnecessarily defective. What is needed are aerodynamic fences mounted parallel to the longitudinal axis aft of the wing (center of gravity) that will help force the nose down with more nose down pressure the higher the angle of attack. This is an item that is benign at cruise (level flight) and active during climb and descend. What happens if the electrical system gets crowbarred? (massive short circuit)? The FADEC (full authority digital engine controls) engines account for this with their own power source (alternator) separate from the main electrical system. In the above scenario pilots will be busy flying the aircraft with one little battery powered instrument in the dark. MCAS won't work then. I understand the Boeing removed the vortex generators from the wings. These help improve lift at low (stall speeds). If they were needed on the previous B737 what was the justification for their removal from a potentially tail heavy aircraft at low speed?
As Steve Blue has noted (see below - chronologically) … The fact that two AOA (Angle-Of-Attack) sensors were available as part of the design-build is the crucial (and fatal) design flaw in Boeing’s initial MCAS implementation. What ever Boeing’s says (or most telling - doesn’t say) about how safe their revision is, there is no escaping the humbling fact that Boeing and the FAA made an incredibly bad analysis and decision to allow the MAX to fly off the assembly line with a SPOF (Single-Point-Of-Failure) that, as was so tragically demonstrated, caused these airplanes to crash with a total loss of passengers and flight-crew. Just my opinion but … I feel very strongly about this and hope that lessons will learned and things will (hopefully) change for the better. 🙏🏽
Especially regarding the fact that a similar system that uses input from both sensors, plus indication to the cockpit, was already installed in a military airplane, when military and civilian world tend to give slightly different priorities to safety vs. performance. That´s point one. Why there even was the possibility that the pilots did not get to know, there was a subsystem installed that could actually assume trim authority in certain circumstances, and how and when and why it does so, is beyond me. If it is true what sensationalist media tell me. In addition, it would be a nice feature to give some kind of indication to the cockpit that the system has been engaged, so the pilots know what they are dealing with. I fully understand, that de-cluttering the cockpit of irrelevant notifications is a safety feature in such a complex machine, to not distract pilots from flying and let them keep focus and situational awareness. However, my totally uninformed layman´s guess would be, that it would be a nice feature to have at least an LED labeled "MCAS", or, for multiple susbsystem input, "AoA warning, auto-trim engaged", or something like that. If that goes on, the plane essentially says "Listen guys, I feel I need to do something to the trim, because my sensors say, you are about to drop the ball here!", so the pilots would at least know what´s going on, and could react following a) " yes, that´s normal und to be expected right now, please switch off", b) "Oh, woops, we didn´t notice, we were busy, thanks for the heads-up!", c) "thanks for the help, we were getting worried, too" d) "what are you talking about? We are nowhere near the situation the sensors tell you we are in. something seems to be off, stop it!" In principle. If the reports are true. If it turns out after the investigations, that MCAS was actually involved in the chain of events that led to the loss of lives and 2 airframes, that would only strengthen the importance of your point. The possibility alone should be enough reason for concern.
Paavo Bergmann I think that the fact they had installed a safer system on the military version is going to be very costly for Boeing. I visualise multi-billion dollar lawsuits sticking to them like confetti to a bride.
@@q.e.d.9112 probably. But then again, hindsight is always 20/20, and what do I know about planes? Also, military aircraft are expected to pull crazy stunts that commercial aircraft wold never think of attempting, so of course they get all the assistance there is.
As an engineer, not a pilot, I have been bewildered by the absence of a system that compares all of the measurements of ground speed and direction, air speed and direction, altitude, position and a lot more, to give sophisticated analysis and alarms when different systems give contradictory measurements. At our current state of technology such automatic comparisons can be done with incredible precision and reliability. We can compare the ground speed given by radar with the one given by GPS, and compare it with the speed given by the pitot tubes, and we can have a simulation of the angle of attack taken from the flap setting, air speed, landing gear setting, balance of loads and so on, that would be compared with the actual angle of attack so that the pilot could get an alarm if they don't match. Many of the procedures that the pilots do are based on the way the technology worked when computers had a small fraction of the power they have now, and I don't believe the full capacity of these new technologies is being used. Am I wrong?
Great answers with solid explanations. Unfortunately we live in a sound byte era and anything as complicated as aviation can’t be reduced to one sentence. If you want to understand, you must be willing to listen. I found this video to be very helpful to my understanding 👍
@@sssri1122 the powered trim System can go faulty witch puts the plane into a nose up or nose down it's why you have to remember off by memory when you have a runaway trim situation, outside of native English speaking seems to be where this issue comes from where they are failing to follow basic runaway trim situation and letting the powered trim crash the plane which is what happened with the Estonia flight and Lion Air they failed to cut trim and was actively fighting the trim system (witch you should never be doing) by pushing trim back up when the system was trimming back down I Believe When Boeing are saying that airlines pilots did not have the correct training they may have been referring to runaway trim situation training which these pilots were failing on (not specifically relating to the MCAS system this is just the runaway trim situation which they should be trained for the last 40 years)
ss sri it is due to the design of the aircraft and engine position. It is described better in another video, the engine thrust has a greater tendency to force the nose up in the max variant, thus this system is in place to counteract this in a specific extreme scenario
Have you watched the news? They ran wild because they took the story and started talking about how unsafe the MAX was. Instead of talking with real pilots who fly the plane they just used talking points that were not the whole truth it were flat out false. The new has been reporting how Boeing charged extra for safety equipment. That is not the whole truth. That is how the news ran wild. We need all the facts in a story, not just part of the story.
Reporting on two plane crashes within five months on the same aircraft is not going wild. The plane was extremely unsafe, the way MCAS could cause the plane to crash. It has now been documented that MCAS relied on a single input.
It's nice compared to hearing various aviation experts on the news with more relevant expertise and detailed knowledge of the MAX 8 than pilots who've never even been trained to fly them have? It's not going wild to report the fact that experts are able to foresee situations in which having the AoA disagree light would indeed be helpful to MAX 8 pilots both without this software update and after it. MAX 8 and 9 pilots should have this light so that they know when MCAS is no longer available to help prevent a stall, because in emergencies knowledge that they're more prone to stalling than usual could influence their decisions. Most pilots haven't received the updated MCAS training as most airlines don't have the planes anyway.
@@jacklabloom635 Not especially, at least based on what we know so far. The software did need correction, as items often do in newer models, but when the malfunction occurred, nothing we have seen so far indicates that it needed to be a fatal event. The crews needed to respond to a runaway stab trim event, whatever the cause. That has been standard training on 737s for decades. Other airplanes have similar risks and similar procedures. That is why Mentour Pilot indicated that he had no doubts about the safety of flying the MAX in the future. The media relies on drama and sensationalism and that often means doing less than cautious, accurate, or knowledgeable analysis, not to mention the breathless tones of panic and fear. Spikes in viewership and ad revenue are strong incentives.
Another blunder of Boeing: new information indicates that the Ethiopian pilots followed the procedures set up by Boeing for disabling MCAS after Lion Air crash.
No they did not. That's what the headline said, but about half way down the article you receive critical information. Yes, they flipped the switches to disable MCAS, but the then for some reason no one can explain--They turned it back on!! There is speculation that something struck the sensor on take off--a bird or an object from the run way.
@@ericbedenbaugh7085 there is an explanation. They were in overspeed and low altitude situation with nose down trim. The forces on the horizontal stabilizer was quite high, and the pilots couldn't manually reset the trim (they have to move it in opposite direction of the forces exerted on the stabilizer). Hence they reactivated the electrical system hoping it would assist them. Instead it trimmed even more down and their fate was sealed.
Eric Bedenbaugh because the manual trim was impossible, that’s why! There was nothing else to do. They re engaged in order to activate the electric manual trim ! You
@@norbertmayer7005 There is a pilot by the name of Juan Browne who has a video on this very topic. Sorry I don't have the link but he gives a very good explanation of proper procedure.
remember the rudder problem with the old 737's but we fixed it and flew safely so we can say that this situation is just a small bump in the road like before and we will clear it.
@@MentourPilot Congratulations mentour! Wish you all the best and I know you can handle the Max safely. I've seen your simulator training and it was an absolutely wonderful to execute those problems..
I have no doubt that you will be flying safely, because of your experience, m but ALSO because the MAX is already a safe aircraft. You will be flying the safest aircraft in the sky, especially after all the scrutiny after these tragedies. I have no doubt that if you were flying one even before the upgrades, even if you had the same situation, that you would have done your checklist and turned off the MCAS system, and safely landed. @@MentourPilot
Hi Mentor! I have never been a fan of the Boeing 737. Still prefer flying the ‘Mad-Dog’ and Airbus. However after looking at your videos, I have a better impression on the 737 system. Do hope to see you flying the 787 Dreamliner one day! Keep up your great videos. :)
My question, can such conditions exist that no matter what happens aircraft will stall and crash because of high AOA and not enough speed alone, regardless if MCAS is there or not? These days companies will do anything to save money, including making pilots climb at max rate to get higher and increase fuel efficiency. And also pilots reliant on software/systems too much making them too bold. And it's not like one can practice stalling a commercial aircraft other than in simulator.
@@couldyourewindplease3653 Meh - few false assumptions there. First, airplanes can easily outclimb the limits that ATC sets for them. They actually have to *reduce* thrust to keep from level-busting or over-speeding during a climb. I also think it's mostly a myth that airlines will skimp by encouraging practices that directly flirt with safety. ("I need you at level 340 in *minutes* skipper! You Hear Me? You better be climbing like a Bat Out of Hell!") More realistic/less sexy ways airlines try to save are *slowing down* a flight once it's at cruise, in order to optimize fuel burn, and by contracting with code share partners with very low margins who pressure their pilots to fly lots of circuits back-to-back like the Colgan Air pilots. Or by lengthening the time between maintenance as Southwest is reported to have done. But if you tried to climb a 7-3 fast enough to stall it during a commercial flight, you'd have a level bust from ATC and a visit from the chief pilot way before you risked a stall.
The answer is the one you might guess first. They saved some money, and booked orders based on a risk. Would you want to fly on a plane that was sold this way? My guess is that Dennis Muileburg wishes he had silenced Sales and told Engineering to embed the dual AoA system and make it fail-safe. He could have done it as CEO. He chose to take the more risky approach. NASA did too when it chose to launch the Challenger. Flying is risky. Some risks can be managed, some cannot. Good companies excel in managing risks. If profit ever becomes the driver risk will rise.
Boeing does no wrong as far as you are concerned, even in the face of them clearing erring in developing an MCAS that depends on data from only one AoA sensor. Unbelievable!
Kwame Boadu Kissi he is simply looking at it with a clear view that is not company biased Both airbus and Boeing have made fatal flaws in the development of their aircraft. For instance with stall susts such and Air France 447, an a330 that killed everyone onboard- airbus quietly pushed a software update after that flight as well that corrected some things they got wrong
He's not arguing that Boeing does no wrong. He's just arguing that he believes they (possibly incorrectly) did not consider AoA disagree light to be a vital safety feature that they charged money for out of greed.
Many thanks for your informative videos. Regarding MCAS, it seems to me that (1) Pilots should have been told of its existence, (2) that it can override their control inputs (3) there should have been a warning light on the instrument panel that would illuminate or flash to notify the pilots when MCAS is operating, and (4) pilots should have had a simple and easy means to turn off/override the system if/when necessary. This just part of a larger problem however. In building the airplane, they changed the engines, changed how the engines were mounted on the airplane (changing its flight characteristics), and changed the computer system. Pilots were left out of the loop, and not told about the MCAS; airlines were told that flight crews would need only minimal training to successfully transition to the new aircraft. There was a rush to get the new aircraft certified and flying commercially, and one has to wonder what other problems were "swept under the rug" in the process.
The take-off at 00:50 seems almost vertical. I guess the commercial jets can't do that and that's just the camera angle. Am I right? If yes, how do they get that kind of footage?
No not classified at all. But the software build for the KC-46 is secured. It could not be shoved into the MAX flight control model without major problems. Boeing chose a simpler (and cheaper) solution. And now they regret that decision.
@@MentourPilot Okay lets to Astana on approach to SFO set to Baritone Boogie with Ground Dispatch reading the Spreadsheet for Frieght to Atlanta Harts-field → Roll new Grad from American Eagle ( my chosen flag for now ) → walks from terminal operations; Just slightly proud our featured PM / Observer does not realize this will be the ride of a life-time and will be lucky to keep all his papers in the same Flight Bag 3 days later 777-200 or 300 or any of the later that do not have the MAX issue to confound as literally no-one is going to get corrections via reading the handy manual on deck ♦♦ Not to be even slightly facetious I loaded the hearings on C-SPAN and nothing technical correct was seen so I went back to work with Juan saying that we really at this time just not know if the 2 toggles take the MACS out of the control loop leaving power for the split-trim on Boeing Control Yoke
Look, what you said at 7:05 is Huge! Boeing had only to add that one feature in with no redundant AOA sensors and two crashes would have been prevented. That to me is an oversight of the highest degree and you can just throw away the iPad training as a reason of concern. The plane/MCAS did not disengage when contra input was detected from pilot. Even autopilot releases doesnt it when the stick is used manually?
Thank you Mentour for this video. Your explanation about how the MCAS installed in military aircraft has more resilience than the single AOA sensors in the 737 Max adds weight to the argument that Boeing overlooked an important quality issue here. Which is to build quality into the engineering process rather than troubleshooting. I agree that we dont know the cause of the accident and we have to wait for the investigations but these 737 Max 8 aircraft in both recent accidents were falling out of the sky, nose dive into the sea and nose dive into the ground killing all passengers. No wonder Boeing has gotten bad press.
@dothemathright 1111 The MCAS system in both the military application and commercial application are used to stabilise the aircraft so they have a common purpose. My point is that building redundancy in to the 737 MCAS is just as critical for passenger safety and preventing airplane crashes that lead to loss of many lives. Thank you.
I'm just an electrical engineer with some computer and programming knowledge - I still can't wrap my head around the fact that MCAS in the 737Max did *not* check the inputs of both sensors (aka redundancy), and that overriding it was made so hard. The more so when the military machine had both things in place (and it seems to work there). It would be interesting to know what decisions lead up to this situation. I would've thought that in the aviation industry cutting corners would be a big no-no, because lots of lives are at risk, not only reputation …
I can't defend the decision, but it seems that it was a late-stage add-on following some unexpected flight test results. The computer system architecture of the B767 (KC-46) and the B737 is not the same, so transferring the software and system parameters may not have been simple. Then finally someone cut corners. It was never a planned and carefully thought out system.
I have so much respect for you Mentour. Pilots like you make commercial air travel the safest way to travel in the world. Having said that, I do have an issue with something you said. At 1:40 in the video you make the statement that “when Boeing builds aircraft, they want to make sure that it is Fully safe to fly”. I think even you would be forced to admit, that if this statement was “Fully” true then Boeing would have been sure to equip the 737 with the same safety features regarding MCAS as the KC-46 Tanker sold to the military. It is dubious, at best that Boeing would think it necessary to create the redundancy’s necessary in the KC-46, but not the revenue version of the 737. A really good way of thinking about this issue is to start with the fact that somewhere deep in the basement of Boeing’s engineering department, a really thoughtful engineer, imagined a very similar scenario that the Ethiopian Airlines flight crew faced when they were trying to wrestle the airplane away from the evil MCAS. These people paid for it with their lives sadly. I guess what I’m trying to say is Boeing had the solution for the problem, before people died. Only the deaths resulting from these accidents, has prompted Boeing to implement the solution. One could argue that Boeing was influenced by an analysis of the probability that MCAS would cause these issues returned an extremely remote chance of this occurring. However, reality dictates that some folks at Boeing thought it prudent to add those safety features for the KC-46. So based on all of this in my humble opinion, Boeing takes very carefully planned risk assessments when they design and build an aircraft, but they definitely don’t always build an aircraft that has every safety feature in their arsenal to make it Fully safe to fly. I guess the real question is why is this so? Usually the answer comes down to money and profit. I believe wholeheartedly in capitalism. It is the engine that runs the world, and has given us this beautiful technology. This is one area where the government needs to be heavily involved in forcing companies to make flying as safe as humanly possible.
I might be dating myself but I thought the main difference between Airbus and Boeing commercial planes was the fact that Boeing pilots, at anytime could take full authority of the aircraft, negating any automatic systems. The MCAS system seems to invalidate what I was told some 20 years ago. Are pilots, both Airbus & Boeing, getting too comfortable with software?
There are always detail differences between the philosophy of manual control, and the actual safety and stability systems implemented. The B737 has long had something called speed trim, which operates in part of the flight regime (fast speeds), opposite to MCAS (slow speeds). Whether both systems were operating simultaneously during the MAX crashes is a disturbing possibility, with faulty AOA data and not anywhere near stall.
It is a very common opinion in the industry that automation has had a negative effect on stick-and-rudder flying skills. I would go further and say that I think it has probably been causal or contributing in a number of tragedies. However, so far as what you were told about pilots being able to take control as necessary, we have still not seen anything that demonstrates otherwise from these MAX accidents. Boeing has generally maintained more mechanical control connections and backups than Airbus, even within their FBW systems. I have never been rated on the 737 but I still know how to stop a stab trim runaway event on that airplane, whatever the cause of it may be (whether a bad servo motor switch or MCAS, presumably), as it has been common to the model for decades. Other crews who experienced this malfunction, including other Lion Air crews, did not crash the airplane as a result. As for misinformation, the media make fantastic sums of money from sensationalism and public panic due to the ratings and ad dollars which result, so speculating and suggesting the worst even in their ignorance is highly incentivized. It is best to listen only to the evidence put forward by the NTSB and their counterparts as well as discussions among those who actually fly the airplane.
Love watching his videos. He's elegantly, indirectly, without trying to offend saying that the problem were... the pilots. But people died, others are not informed, so it's easy to throw everything on Boeing. I feel bad for them. Really bad. And of course for the families of the ones who aren't here anymore, but that's another story.
For the folks who aren't technical, "redundant" in engineering is in no way synonymous with superfluous, as this video seems to indicate that it is. Redundancy is a safety feature.
Not being a pilot myself, Boeing’s pitch recovery has always seemed insufficient. From other videos on 737s, I understand it would 4-5 seconds of full attention to unfold the handles of the trim wheel, then several more to trim in optimal conditions (without MCAS trying to make inputs.) So if the computer lost situational awareness, even if prepared pilots reacted immediately, they would be unlikely to recover the aircraft before it lost thousands of feet! Am I missing something? Peter always said you should slap a pilot and take controls if they are taking chances, why allow planes to exist with computers that can do so much damage? This is not an issue that will only affect Boeing, it is an issue of low airworthiness standards all around. Grow a pair and tell the industry if they have a problem!
the only defence that boeing has is if they can prove the MCAS did not activate in both crashes. outside of that, no jury is gonna buy the story that boeing didn't design a defective plane. they can argue all they want, but vast majority of the 737 pilots didnt know how to turn off MCAS, which speaks volumes of boeing's mistake.
Doesn't your job as a pilot depend on the 737 max 8 being in the air? I feel your opinion is compromised somewhat so I take it with a grain of salt. Boeing Engineers in other parts of the internet, have indeed concluded that the larger, further forward and higher mounted engine nacelles begin to provide extra lift at high AOA pushing the nose up...the very reason MACS is being used to correct it. The problem is they thought MCAS would be 100% seamless, it turned out to be less so.
I think the problem might have been that once the sensor malfunctioned the MCAS pushes the stabilizer into a nose dive. If you switch off MCAS jack screw motor to compensate you also switch off the entire system controlling the stabilizer? This means that the stabilizer stays in nose dive angle? Does the MCAS software know the stabilizer is not moving because the jack screw motor has been switched off? Does it loose track of where it thinks the stabilizer is positioned at? How to get the stabilizer from nose dive state into a nose up state after you shut down MCAS motor? Continuous trim from the pilot until emergency landing I suppose? Can the MCAS enter a reset state when motor restarted? Can the MCAS handle motor restart at all? Maybe? That would require MCAS to be able to detect the current stabilizer jack screw position on motor startup and go into a default state. If MCAS cannot detect horizontal stabilizer position on motor startup it cannot know what to do, even if a faulty sensor fixed in the mean time. This could also mean every time you restart the MCAS motor the software could "authorize" the jack screw to move the stabilizer a certain amount of degrees again, possibly past a maximum amount that it forgot because of the restart? So every time you restart an MCAS motor under faulty sensor, it adds another 5 degrees to nose down or something. That is a very scary situation. These are all possibilities that I have not heard proper explanations for. If I was a pilot, those are the questions I would worry about.
Just like the DC-10, it took many crashes to work all the bugs out. The 737 Max may have been inappropriately certified, the FBI is investigating that. So there are higher than normal chance that there are other bugs that have gone unoticed. I'm not going to fly in a 737 Max until at least 5 years later (if they have no additional crashes).
I avoid flying when I can, but for international flights I have to fly. Usually they are on 777, 787 or A380. Which all have pretty good safety records.
Now, the Wall Street Journal wrote, by information of a Ethiopian investigation insider, the pilots had 4 times the electric switch because MCAS disabled like Boeing said, tried to trim manual by the wheels like You demonstraded in your Video, and reactivated because it seam, the pilots wasn't able to get the machine under control by manual trim. Can it be, the Max is to difficult to trim manually?
The answer is yes, all models of the B737 are difficult to trim manually (see Mentour's previous video). However the MAX and MCAS is the only case where this has become a safety critical situation.
It becomes more difficult when you still have the throttles in TO and not pulled back to cruise/climb and you are constantly getting overspeed warnings because of your excessive airspeed at a low altitude in very dense air....
Boeing "oops" omission and failure to provide needed redundancy could have led to over 330 deaths. If negligence can be proven, the persons involved should face criminal charges. If final investigation reports indicate Boeing's negligence, the company shall pay the money for damages to the families in accordance to it's size and value. If it's proven that FAA has "outsourced" the certification to Boeing itself (!) also FAA should be prosecuted. Lot of "ifs", but I rely on information available to us (public) which is at that time very scarse. Thank you Mentour on putting some light on it.
Excellent video! To those throwing shade that he sounds like he's covering for Boeing, I disagree. He's separating the hype from the facts. Boeing not putting a redundant sensor and not making sure that pilots understood this system was indeed inexcusable but he's not addressing that aspect of things in this. What I gather from this is that with a redundant sensor and full pilot knowledge of the system, there is nothing particularly unique or risky about this plane or this type of system. The media and the regulators should be going after Boeing for their behavior as two very avoidable crashes are on their hands. But Mentour is not addressing that. He is just separately saying that where we are now this plane is as safe as other airliners. If he didn't he wouldn't want the risk for himself or fellow pilots. I appreciate hearing this sort of info from him versus a journalist or politician.
Hey Mentour, quick question. If the alpha vanes are situated along the longitudinal axis of the aircraft but on opposite sides of the fuselage, wouldn't the readouts on the AOA indicator disagree in an ascending or descending turn, or at any pitch attitude other than zero with a given amount of bank angle established (e.g. maintaining a heading in a crosswind)? Love your Channel, would be thrilled if you answered this question in a video! Keep up the good work!!
Chris Odom just my non-expert guess: The difference would be slight and predictable. I would assume the program has parameters to distinguish between normal and unwanted maneuvering.
Chris - Although the alpha vanes are on opposite sides of the airplane, they're on the fuselage not the wings. Even in a turn the air on both sides of the fuselage should be the same (assuming the airplane is in a "coordinated turn" and is not "skidding" or "slipping" sideways). Realistically, there is going to be some margin for error programmed into the system, so it won't show a "disagree" unless the two vanes mismatch by a certain value or greater (perhaps something like 2 degrees' difference). That would allow for minor variations in calibration, airflow over the fuselage, and things like turbulence to cause momentary discrepancies that won't be so large as to cause a "false alarm" that one of the vanes is reading incorrectly.
I think it is surprising that any competent pilot would sit there watching the trim system spin out of control and not think to shut it off. We try to design idiot-proof planes with features like MCAS and some pilots seem to forget even more about flying.
it's likely that there were more problems than just one and that could have caused confusion and there was only a VERY short time to sort it out, so we shouldn't judge people if we know only some fragments of the situation where we haven't been ourselves.
@@mattesrocket lion Air one they had plenty of time and they was actively fighting the powered trim system when they should of turned it off and gone manual,, But after this update(when they are back in the air) the system will operate the same as the boeing tanker variant of the MCAS antistall system (if you pull back in opposite of what the MCAS system is trying to nose down the plane it will now automatically disable MCAS anti stall trim down without you having to stab the trim (cut power to trim) it will also have redundancy on the sensors so less likely to have one sensor trigging antistall MCAS and stick shaker
Reason, the NTSB has made note of this in the past, that the feel the increased automation and control by computers, has had a tendency to reduce pilots ability to react and respond correctly to issues that occur when the automated systems fail or something happens outside their control authority . In essence pilots are losing their perishable skills to fly the plane manually in adverse conditions.
Also there has been some mention of witnesses seeing smoke and debris falling from the plane just after take off, and some data has seemed to show they tried to rotate early off the runway poss due to a faulty speed sensor, which may have caused a tail strike and damage to the plane
@@GNX157 Boeing does not want that it to be that way when a situation happens, I am not sure what was going thro there minds (who ever authorised this badly thought out way to stall recovery) the press love to find holes they can poke at when they think basic safety features are missing when they are not even there on past planes not safety related now it's going to operate the same as the Boeing tanker version, watch all of video for it (or last 2 minutes for it) on the other hand Airbus are taking the automation too far and putting inexperienced or even experienced people into there planes and crashing them when something goes wrong (and they still blame the pilot for the crash) basic things like force feedback is missing on the joysticks on Airbus so you have to follow instruments completely to make sure the plane is doing what you expect it to do (as you can't feel it on a Airbus)
Maybe because the media's tales to generate that reaction from you aren't entirely true...? Ever thought of that? Ever heard of the Toyota unintended-acceleration scandal? It cost Toyota billions, they had to make a few changes, but what did later analysis show was the biggest factor? Engineering or media hype? Ever heard of the media trying to demonstrate the danger of GM truck's side-saddle gas tanks? Were they honest then, either? When someone makes money from your reaction, they are going to tell you a whopper of a story every time they can. You would take their tales over all the pilots and engineers involved in these aircraft? Why would any of them have to be paid by Boeing to tell you the truth when their own lives are the ones that will often be at stake flying them far more often than any passenger's life is at stake riding in them?
And this is why I hate media. They should be required to fully watch videos like this and NOT take them out of context before reporting any of their stories.
It is incredible how Mentour defends Boeing stating that he is confident in the safety of MCAS once things get sorted out... Yes, MCAS issues will be resolved. But never forget why it came to the problem: Boeing wanted to sell fuel efficient airplane. They added new engines to old airframe, and made an efficient flying brick. In order to make it fly more or less "safely", they added MCAS. In order to sell it, they hushed up even its existence... You follow me? It was criminal negligence for the sake of profit. How Mentour can affirm that he will be perfectly safe flying it? How many more hidden issues (not MCAS related) may be lurking beneath? If the design philosophy puts sales pitch (no training, fuel effciency) before safety, the airplane is flawed.
You are 100% correct! This video was saying pilots need zero training and all aircraft are alike. This video is to cover Boeing, not the satefy of it's passengers! MCAS was added becausr the aircraft was unstable! Too big of an emgine for this aircraft. But, it's all about $$$$. Rather than create a new aicraft they just added features to a 1967 airframe! Poor design! Poor Safety! Greed killed over 300 passengers!
YES. The problem is not there was a mistake in the design. All aircraft manufacturers make them, and airplanes fall from sky from time to time due to these mistakes. Here the problem is the design philosophy. And much worse, after the first accident, Boeing most probably knew pretty well that their system is in trouble, but hushed it again, hoping that they would be able implement the software updates "under the cover of darkness" so as not to inflict PR damage...
@@michailbelov6703 I have worked at several aerospace companies, including Boeing. I have a bachelors in computer science and a master's in industrial engineering. I was in the US Air Force. I was also a private pilot. It's clear to me that you have no knowledge of the engineering aspects of why this happened, and you're falling back on what most ignorant people do, which is to focus on finding a villain. There are no villains with evil intentions - just overly-confident engineers and management.
The fundamental problem that everyone seems to want to ignore or fail to understand, is that to produce the 737 MAX, a new and larger engine was required. That its larger size meant it has to be placed forward and higher than the position of the previous design. As a result this alters the centre of gravity of the whole design, and unbalances the aircraft constantly. Never mind the problem of altered aerodynamics ! Everyone seems to think that a software package called MCAS is the solution. But no matter what MCAS may or may not do in controlling the position of the flaps and or rudder, this does not remove the fact that the plane is constantly unbalanced. It only means that the aircraft's control surfaces must now constantly fight the imbalance of the aircraft for the duration of every flight. How long before the constant increased stresses on the airframe, and the moving flaps & rudder etc, result in metal fatigue and "bits falling off" ????????
Again a very well done video about airliners. Amazing the press could ever get anything wrong in reporting on aviation. :) We also do not navigate with iPads but the iPad might have the digital chart on it. Yes pilots use iPads for learning about the aircraft, and before iPads we used paper books, large pictures, movie projectors and overhead projectors to learn about the aircraft. But we still use real aircraft or simulators to learn how the fly the aircraft. I think it is accurate to say that all jet airliners have AOA vanes and AOA is used by the aircraft systems, but pilots who fly the aircraft do not need to have an AOA indicator to fly the aircraft safely. We had the AOA vanes on the 757 and 767 that I flew for 20 years and never had the ability to read actual AOA in the cockpit. We could indirectly have an idea of AOA with some of the indications but could not know what AOA was at any given time.
Look like very oriented answers. As we know now that MCAS was activated during the flight of Ethiopian Air too, there is no time to argue. You says: "737Max is the most scrutinized". Well, this is irreconcilable with reality. What is the reality: - some software designer write a critical code with multiple flaw: use of only one sensor where the is two availlable, repeatedly trim down, take over the pilot, and change of directed sensor each flight making error detection harder. - some other / same software designer create an optional warning system for AoA discrepancy without notifying the risk of MCAS. - some boeing reviewer did not catch the issue. - some FAA security scrutinizer did not catch the issue. And i do not even account for questions like: why MCAS is in the glossary of the 737 max pilot manual without being described in the text? Why north american cie got the AoA discrepancy warning installed and non-american ones not? etc etc... To have such a series of failures in a process clearly indicate that the process itself is failing. It is not an isolated event. So the question is : what are the others hidden 'features' ready to kill people in this company planes?
@Mentour Pilot How come in the Airbus, it never had this nose dive issue resulting in crashes when it ALSO has a system that points noise down when the airplane is stalling/going too slow. Why can't Boeing just copy them?
2 interesting questions though. 1. The Angle of attack sensors are in use on many planes and do not feed false readings. Why do we suddenly get false readings on the 737max? 2. Is the design of the 737max fundamentally flawed with its large engines positioned forward and higher? That is in the panic to compete with the Airbus A320neo Boeing patched up the 737 in an unstable way that will always require high input from MCAS ? Love your videos by the way.
Many of you understand what our friend Mentour Pilot is trying to convey. Some of appreciate his candor when discussing what has to be the worst airplane manufacturer PR disaster since the Hindenburg. A few of you understand the knowledge that, as a pilot, he is trying to convey. Ask yourself, is this the kind of person I want on the flight deck when my life depends upon their experience? Or would I prefer an inexperienced person in command, one who was trained but may not have learned what they need to know when things go bad (and on the flight deck things can go bad quickly if you don't know how to assess your situation, and then respond according to learned procedures). Panic is your enemy. Mentour knows how to handle stabilizer runaway (checkout the video) so he could have handled the Lion Air and Ethiopian accidents. Sadly the four pilots on the two aircraft did not know what to do. And their flight manuals did not tell them how to handle the situation they were faced with. Blame Boeing first. Then blame the US FAA second. Then blame the US Dept of Transportation third. And, because the safety of the flying public was of no concern to him, Donald Trump, who shut down the FAA when Boeing was ready to move forward for a fix to the problem. Oh, and just remember, Donald Trump's former Head of the FAA left service over a year ago. For over a year the agency has been headed by an acting head, as are many positions in the US Govt under Trump. After the Ethiopian accident, and the embarrassment to the FAA Trump has nominated a new Head of the FAA. There are many facets of the US Government that are functioning in a management void created by the current President. Please factor that into you analyses of what is going in the air safety realm right now.
I mostly agee with you, but went in the mind of the software engineer to use a single sensor to allow the auto-trim to go to full nose down, disregarding the pilot pulling on the yoke, the second AOA, the inertial platform, the gravity sensor all showing that the the plane was going in a regular take-off angle? Clearly a software update can take care of this problem, The question remaining is how many others short cut Boeing toke on this plane.
So if the military version of MCAS already had the two critical features they are adding to the civilian version of MCAS then this begs the question why are they different? It sounds like they had already devised the best and safest solution for the military version of MCAS.
The architecture of the B767 flight control computers is different from the B737, so it was not possible to use the identical version of MCAS on the MAX.
@Gordon Richardson I think you misunderstand quantumac statement. In military, MCAS have more redundancy (and all of the sensor needed for redundancy is on the 737 MAX 8 too), in addition the system can be "easily" overridden. Thus when MCAS on civil does not have redundancy, this baffled a lot of mind (and more when we knew that BOEING actually has designed MCAS system which is "safer" in military airplane than in civil airplane. (of course you might say but computer and plane different, here the problem: the basic necessity apart from computer and plane different, it is still the same. MCAS should have redundancy and can be "easily" overridden)
eternalinsignia I understand that point, and am not trying to justify why that decision was made. I was just pointing out that the working and tested system could not be simply copied across two different computer systems.
quantumac The military B767 version of MCAS is not certified for passenger aircraft. Allowing the column cutout switches to override MCAS would violate one of the many technical requirements. Safe and effective are not always the same.
Anyone want to bet against that totally different software teams "designed" the 2 MCAS systems? That's probably where the B-737Max team didn't read the military version specs (if they even could). The civilian team may have only been given a general idea of the military version.
As an avionics engineer for 31 years, I am absolutely appalled that the MCAS system depended upon a single Alpha Vane sensor.
All flight critical systems must be dual redundant in function. In a 21st Century designed aircraft this is inexcusable. There are NO EXCEPTIONS TO THIS RULE.
Chances1957 - I am also appalled that the design doesn't provide for a feedback loop from the current stabilizer position to the MCAS so that this bit about repeated and cumulative movement of the horizontal stabilizer can be better controlled. That is, if the stabilizer is already moved to a 3 degree nose-down correction due to the first MCAS activation, the MCAS should be aware of that before any attempt to move the stabilizer further, especially if there are signs that the crew is fighting the MCAS.
WakeUpAmerican000s I absolutely agree with your comment. Certainly as a design engineer I would have implemented your suggestion otherwise you will arrive at the situation we have witnessed. Thanks!
Dmitri Kozlowsky MCAS May be dependent upon TWO sensors after the recent modifications, but it was only dependent on one sensor at the time of the two crashes!
@@Chances1957 Is it true that the MCAS alternates between the AOA sensors each time it is switched on & off? Somebody mentioned this in another video.
@@Sky360Phoenix I am not aware of this. As far as I am aware, the unmodified system relied on just one AOA sensor - pathetic really!
Hey Petter, as a Verification Engineer of Embedded systems. I simply cannot fathom, how the guys who tested/verified the MCAS system did not ask the question, what will happen if we have a mismatch in the alpha veins or if 1 or both pilots are applying manual counter trim... or if the trim wheels are held with X speed that they are supposed to...
In my line of work, we always ask ourself, what will happen if such an input misbehaves.
I cannot fathom what the Engineers that tested and missed this are feeling. People died... if I was working on the MCAS... thank god I am not.
Yeah, it will stay a mystery
Agreed any system analyst would have asked the same.
Im sure that your colleagues werent the ones that called the shots.
@@Joaking91 You are wrong... our job is to verify the system. Yes we don't design it, or don't set the requirements... but we always ask the questions... why is this like that, what if, how is this etc.
From those questions often the guys designing it get a second opinion and they rethink it.
P.S. As a good verifier I am always questioning everything. Even if a detailed specification is written, explaining everything. It is written by a human. There is bound to be an error or misunderstanding somewhere. So is every piece of code I work on. You never know how much code is legacy from a previous system. How much of it is new. What quality it is. Etc
...
Ah but MCAS has NOT caused these crashes that we know of YET. Wait for the reports before blaming MCAS.
I think your giving Boeing way too much credit. 2 of the main aeronautical engineers who were principle designers of the 737 MAX since have walked away from Boeing over safety concerns over the airplanes air worthiness...On top of that..
There is an American Airlines Senior Captain of their 737 MAX Fleet is on T.V. saying he no longer supports Boeing and had a meeting with top executives at Boeing along with the Pilots Union here in the U.S. and raked Boeing over the coals and insinuated a huge betrayel by Boeing to the Pilots and the flying community.
I would really like to hear you comment on this please.
Thank You
You are being very kind to Boeing. They are paying a price that they well deserve to pay.
*> They are paying a price that they well deserve to pay.*
No, 384 souls paid the price. The rich execs don't pay ANY price unless their wives and kids die screaming and crying when their airplane falls out of the sky.
Luxi Turna sad but true
As I said in a previous video on this MCAS system, there should always be dual redundancy in critical systems on aircraft. There are no exceptions to the rule - NONE!
Control column inputs? They should only be recognized if both pilots are giving identical inputs simultaneously? It could be argued that it might have saved AF447, but it still sounds like an important exception! :-)
@@ReflectedMiles Using two Alpha Vane inputs instead of relying on a single sensor is what I meant by making a system "dual redundant". The planned changes to the software will now require the use of both sensor inputs unless their respective readings differ by more than 5 degrees. Logical!
Chances1957 I understood your reference. I was just pointing out that one exception to redundancy is in the most important sensor inputs of all to the system-control manipulation by one pilot, not requiring two pilots to attempt control of the aircraft at the same time.
@@ReflectedMiles Yes okay, understood. Actually I thought that this was what you probably meant. Thanks.
@@ReflectedMiles What's the analogy here? A pilot who goes nuts, or a control column malfunction? Pilots can watch each other, both can realize there's something going wrong with one control column and decide to use the other. The pilots are already the system checking that the control column is working, and that each other (humans) are working and acting properly. Similar mechanisms were missing in the MCAS.
Mentour: I am a big fan of your YT channel, but I have to say that in this video, you really sounded like a Boeing apologist. I understand everyone has biases and you realy love flying your 'Baby' the 737, but I think even you could admit that Boeing made a mistake. Anyway, keep up the good work.
Yes, that‘s my opinion, too.
- Boeing knew how to do MCAS correctly, but they did not in the 737MAX
- They used 1 sensor for a flight critical system which is not allowed in civil aircrafts
- Boeing did not include MCAS in the iPad training, although it changed the behaviour of the plane like NEVER before
- Boeing did inform the FAA in a wrong way about how much the MCAS can interfere
So overall, the reason for all this seems to be to avoid that the authorities order a simulator training. Which would have made buying this plane more expensive. And Boeing would have lost more orders to the better A320.
Overall Boeing deliberately (!) cut short on quality. There is NO excuse for this.
It is always possible for engineers to make an mistake. This was no mistake. It was deliberate action to only use 1 sensor and not mention the all new system in the training.
Mentour: I find it strange that in the video that fact that 2 planes crashed is not taken into consideration when talking about if Boeing did well and if that plane is safe to fly.
One could think you talk about the theoretical case that something with MCAS could go wrong. It went terribly wrong. Boeing will have to pay for this in several ways. Because it was no a „fault“, it was a „fraud“.
Calling it fraud is just silly. You sound like you work for Airbus. @@auronoxe
No, I don‘t. I‘m an engineer in healthcare. If our company would know about a SW error that could kill or just even hurt hundreds of patients again (!) anytime, we would stop our systems to be used by customers immediately. If we wouldn‘t our company would be closed by the FDA and the EU authorities and someone would end up in jail. Safety critical sub-systems/interfaces/... need to be made error prone TWICE in our business according to regulations. That‘s exactly what Boeing didn‘t do, although this is done for life critical systems in planes, too - normally ;-)
@@drock5407 He is a realist. I fully agree with him. Boeing screwed it utterly and completely, and I am very confident that criminal charges can and will be brought against them, and it will be succesful, unless they can evade it due to jurisdictional issues. The only unfortunate thing I see here that Boeing did not crash in the USA... Prosecuting them would be much easier.
You are absolutely right, Mentour sounded like PR person for Boeing. He said plane would be thoroughly tested by FAA and other agencies to make sure it is completely safe for you and me! Yeah, wasn't it 'thoroughly tested' to be licensed and yet we are here. They certainly knew this is flawed plane and they didn't even tell the pilots about MCAS, which was also flawed, but they still sold and delivered it, and now 350 people are dead. If this is not a shady business, to avoid using stronger but more realistic word, I don't know what is.
Considering AOA indicators as "optional" based on your prior experience with AOA sensor/indicators is irrelevant when it comes to the 737-MAX because the critical MCAS system as (fatally) designed depended on those AOA sensors.
true, but a bad aoa sensor mcas can be turned off. You can easily still fly manually and trim yourself without any MCAS. Maybe boeing put too much faith in pilots diagnosing and handling bad sensors. Its not really a design flaw, but humans getting confused is a tough thing to design for.
@@wildwest1832 well expressed
@Wild West that is not really the situation. There is no "just turn off the MCAS and continue as usual"!
You can cut out the trim motors but that does not disable only MCAS, it disables ALL automatic and power-assisted trim. (ok there are 2 switches, but not a separate one for MCAS only)
So there is no "easily still fly manually". You will have to turn the wheels by hand and you can see in the other video that that is not easy. Remember you not only have to revert the change made by MCAS but also have to perform all other trimming up to the landing.
@@wildwest1832 Worse than a design flaw, Boeing likely committed a criminal act when for commercial reasons they wanted the new 737 version to handle like the old ones. But changes in the new version required an additional system to handle certain flight situations. The development of that system and the safety analysis of its implications were rushed through. Pilots were not informed of it and not trained to counter its failure.
So, instead of copying the MCAS from the military version that works well (uses two sensors, turns itself off if the sensors disagree, turns itself off if the pilot tries to move the nose up), Boeing made a civilian version of the system with one sensor and more difficult to turn off. Even though the aircraft had two sensors anyway, so it's not like Boeing saved money by not installing one of the sensors.
This looks to me like the software job was given to an intern or a new employee as a first assignment and it was made very simple - if sensor says AoA is too high (and flaps up, thrust high, autopilot off), trim the nose down, unless the pilot disconnects the trim motors.
But yea, the 737MAX is probably going to be the safest airplane after this. If there is another crash due to a design problem (problem with the fix or an unrelated problem), that would be really bad for Boeing, so I think that the whole design will be checked.
I really get the bad design part of the story (reading how the MCAS works made me ask myself “isn't this a rookie mistake?”). What I don't get is how was it possible that the pilots of the second crash didn't know. I mean, you pilot an aircraft and you know there was a crash of the same model and some speculation on the reasons of the crash was already out there and the MCAS is mentioned and explained. How come they didn't think of the stab trim cutoff?
Dumb American schools.
@@WilliamJones-Halibut-vq1fs From what I read about the "new math" crap (where 3*5 is not the same as 5*3) and forcing the students to strictly follow procedure instead of thinking, then I'd say at least that part is not so great.
@@WilliamJones-Halibut-vq1fs. American baseball teams are all best in the World Series though. Can we assume this study was carried out by alt right Americans.
@@WilliamJones-Halibut-vq1fs blacks, hispanics, and you?
Finally a voice of reason and expertise on TH-cam. There are so many people eager to jump on the lets bash Boeing bandwagon who hardly know one end of an airplane from the other. Keep up the good work. I found your explanations clear, concise, and accurate. I am long retired, but have logged around 25,000 hours in Boeing 727, 757, & 767 aircraft, and am amazed at the rush to judgment of so many uninformed people. .
So ? What do think now ?
Making a system that can fly the plane into the ground based on one erroneous sensor is negligent, but the worst aspect was keeping pilots in the dark as to the existence of this system. They should have been briefed on it and trained in a sim to recognize the angle of attack sensor failure and practice dealing with it. If every MAX pilot had done this it would be much more likely the crews would react in the right way instead of flying into the ground struggling to understand what's going on while consulting a manual that doesn't list the MCAS system's existence. From what I can see pilots were kept in the dark precisely to avoid the need for expensive sim training.
And so it's probably management at Boeing and the airlines that, while not directly responsible for the disasters, they did set up the conditions which led to it. And every one of us who chooses an airline ticket based on price has contributed to those conditions being set up. In the end, there is a certain minimum cost associated with doing things properly.
I flew these aircraft from mar to jun. They were fine but I had my heart in my mouth praying nothing would go wrong. AA uses 737s a lot and loads of people were boarding them. In Some cases you can't choose other brands. The destination is only accommodated by 737s. So you're stuck with it. I tried the train to Fresno . 4 days solid. Bus same thing. Just saying.enjoy the flight. ù can't take a boat.
Thank you for putting this out. It’s great to hear from someone that actually uses the product.
Fantastic as always. Love the way you explain everything in layman’s terms. Keep up fantastic videos!
Thank you! I’m happy you like it!
MCAS exists to "save" the plane from stalling when the pilot goes full thrust and pitch up, aka to prevent an unrecoverable stall.
However now Boeing has added all these defeats to MCAS it is not likely to actually trigger when it SHOULD.
So instead of having the plane crash because the MCAS is forcing nose down into the ground, we accept the risks of having the plane stall out in a climb.
All of this goes back to: "Is it a good idea to take a design from 1967, patch on giant engines that require pontoons to move these behemoths forwards and up (and extend the front landing gear) so they dont scrape the runway, and then patch all the flight problems that result" --- INSTEAD of: actually designing a plane which is balanced for these engines in the first place, further back under the wing, with taller landing gear all round, and the right amount of fuselage ahead of the wings.
All in the name of profit.
Agree with you 100%. Explains why none of the other Boeing aircraft needs MCAS. Sad thing is they will issue "software fix" and say "have a nice flight." We all know it's not a properly designed and balanced plane for those new engines. It will always be a "dog" to fly with pitch up tendency. They have a chance to fix it now. As you say longer landing gear, move the engines where they should be, modify the wings and generally do a proper fix by balancing the plane better for the new engines.
So do you think 737 Max has a pitch stability issue?
@@manaoharsam4211 MCAS is the evidence that there is some issue at high thrust and high ANU. Airplane weight may also be a factor in this. Such as (either) takeoff (high weight due to having more fuel at start of flight) or more likely during a go-around (an aborted landing of an aircraft that is on final approach) (low weight aircraft).
I agree with you. I find there were a lot of arrogant Engineers at Boeing when I worked there. Also management knew nothing about planes. Just bean counters.
when I worked in area of aero elastic instability not one Engineer had a clear knowledge of subject. They were push computer button Engineers. In fact when I went to a professor class I could tell the skill level was very poor of students from all walks and companies . I told everybody be at Airbus or Boeing I am scared to get up on a plane. When companies pay you good I money my approach is do the best job of learning even on your own time in order to do correctly. This is fun work. Some Engineers I worked with they prefer fishing than aerospace. I say leave then.
@@DemoEvolvedGaming is the issue on stability.
I believe that Mentour explained what needed to be said and understood by the flying public and those that are interested in aviation... I believe that those in the media were not capable of explaining in layman's terms what Mentor said very clearly and jumped to conclusions without understanding how planes fly and how pilots fly them.!!!
I disagree, he has more conviction (the 737 is a fantastic plane) than knowledge (the mcas is just there to ??)
disagree.. he's making excuses for boeing
There was a very similar circumstance of a safety feature the pilots didn't know about causing an accident with SAS 751. It was a DC-9 (MD-81) and SAS had fitted ATR - Automatic Thrust Restoration - to prevent pilots throttling back too much for noise abatement reasons. As 751 took off, ice came off the wings into the engines, damaging them, the pilots throttled back but the ATR (which they hadn't been told about) overrode them with full climb power, which caused the engines to fail completely shortly after at 3000 feet. They were incredibly lucky and managed to crash-land in a field with no fatalities.
Actually I mis-spoke - the ATR selected takeoff power, which is worse (for a sick engine)
That was an excellent update. But Boeing needs to have an independent organization do some serious investigation as to how these very poor design decisions were approved and tested. It appears to be gross negligence. They are going to be sued, there is no doubt about that.
Billy ... Should an independent organization investigate the PAN-PAN component of the 737 MAX story?
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@@kradius2169 My understanding is that procedures were followed on that and resulted in a NTF on a return to service test after landing. Likely the NTF was caused as MCAS alternates on which AOA to use in each flight segment. So it had cycled to the good one after landing and the ground test then checked the good one. Then the next flight it had cycled back to the bad one and crashed. That is just a test procedure problem that is easy to correct, a little late though. But will be changed anyone since update uses both AOAs.
Billy ... How did the pilots of the previous day's flight of the doomed Lyin' Air 737 MAX pull out of their PAN-PAN situation?
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@@kradius2169 They probably don't have recorder data for that event, but I thought they determined through crew interview they pulled the power to the electric trim. In the crashes, they didn't have enough altitude or experience to figure that out. The recorders from both crashes should indicate that is why pilots could not recover.
Billy ... Not enough altitude? I thought the Lyin' Air doomed "pilots" struggled with the plane, fighting valiantly against the flawed Boeing MCAS system, for minutes?
How long would you struggle with the cruise control on your car before you tapped the brake or hit the switch? ... Minutes?
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Your answers are not convincing to the controversy of Max8. The MCAS and MAX handling turned out to be an engineering disaster of Boeing and a big shame of FAA certifications. But from your comments, it seems that nothing is serious.
You missed the points. Watch the video again.
Thats because the crashes would have happened a lo earlier in production and reports of bad handling too
Henry Delana the audience would like to understand what caused the two accidents from a technical perspective. Unfortunately from the video I could not find much reasonable doubt for potential flaws from the point view of aerodynamics, S&C, flight control or fly-by-wire.
Mcas played a role but didn't cause the crash read the report ....if you know how to read.
I want to accept your endorsement of the 737 Max, however I just don’t believe that Boeing has actually come to identify the problem. Their unwillingness to ground them after the Ethiopian crash demonstrates their intransigence.
Boeing identified the problem and started working on fix in 2018. The fix required that they get FAA review. Donald Trump shut down the US government in December. No FAA employee could assist in getting the fix approved while Trump refused to budge. The FAA is culpable, as is the Department of Transportation and it's Secretary who is the wife of Mitch McConnell. If you wish to inform those who are responsible for the Ethiopian accident do please include Elaine Chou (Secretary of Transportation), Mitch McConnell (who refused to halt the government shutdown), and of course Donald Trump whose shutdown materially interfered with the solution that could have saved lives. Please note the use of the term "materially interfered".
Having identified the problem and then, after the second accident, claiming that nothing is wrong and the plane is safe to fly, only makes the matter worse for Boeing.
@@Rob2 You are correct.
@Röhrich Oak It is unfortunate, but there is a lot of history behind what has happened recently. The US FAA has been encouraged by the US Government to hand over regulatory responsibility for airplane certification to the companies involved. The implication was reduced budgets for certification. The FAA caved, and the US Government cut their budget (which had to have the approval of the Secretary of Transportation, a Presidential appointee). This was not Trumps doing. Think of the last Republican President who proposed spinning Social Security out to the private sector prior to the Great Recession (that his economic "let the banks do what they want to do" created). That former Republican President is safe from harm in Texas. Meanwhile Boeing chose to finesse a training dodge that would assist sales. The dodge backfired with the Lion Air accident. With certification already in place Boeing was forced to propose a solution that required FAA certification. The current Republican Administration shut the FAA down for other than "mission critical" functions. The current Secretary of Transportation could have challenged the situation by stating that the FAA team working with Boeing needed to stay on the job so as to prevent another accident. If that protest was made it was kept very quiet. Her husband was assisting the President in holding the FAA hostage. This is not to say that Boeing is not most at fault. Boeing stuck to the "no simulator training required" mantra that their Vice President had pressed to Muilenburg as an important hook for sales. Muilenburg was also getting briefings from legal side of the issue. Any admission of guilt would be used in lawsuits which were sure to come. The Legal Department knew their only best choice was to negotiate settlement out of court. Their worst fear was a class action. So now you know what Muilenburg is dealing with. His sales-oriented solution was blocked by a Republican Administration's obsession with holding the government hostage for whatever reason. The Legal Department told him if you ground the aircraft it will be an admission of guilt. To some it may seem ironic that a Company who gained sole control of the US commercial airplane market could find themselves in such a predicament. A competent manager would never have accepted the Engineering decision to use a single-point-of-failure solution that could put the plane in peril. A competent manager would not have accepted the Sales suggestion that training for the single-point-of-failure was not required. A competent manager does not run the Boeing Corporation. In order to gain the industry's trust Boeing's Board will have to show that the Boeing Company is better than it has shown itself to be recently. They can start by firing the CEO.
@Röhrich Oak You are getting dangerously close to the truth.
Mentour, your videos make everything much clearer. Your approach to whatever the subject matter is never feels like you are forcing your personal opinion down everyone’s throats. You give factual and very straightforward information based on what has been documented by the various aviation authorities. Some other YT aviation gurus feel that they need to use brute force to drill the subject matters into our heads. I’ve personally found that you teach very well and I hope that you will be recognized for doing a video in the correct manner. As an aside, we can also get to see your hairy kids as well showing that you are human and don’t consider yourself to be at a level above your audience. Great job as always.
Hah, at 0:48 shows MAX flying almost vertically with zero problems. A couple of other pilots had the same problem and just turned the system off...a couple others just crashed the plane. Shawn White can jump a snowboard, but I can't...should we blame the snowboard?
I thought that was a flight test? With zero passengers and flown by Boeing pilots who probably are a lot more familiar with the system. You really can't blame the pilots for the ill fated Lion and Ethiopian planes. My friend is a pilot for Delta and has said many pilots are disappointed with Boeing.
Drew P Knutz My thought exactly! The 737 MAX was successfully flown over 41,000 times for over 120,000 hours delivering over 6.5 million passengers but now it is the most dangerous machine ever invented and Boeing delights in killing their customers!
2 planes down breaks my heart, I really hope they make it right for the lost lives. I have flown on the max more than once. SAFE TRAVELS,
They will make it right only for their profits which might be compromised as a result. They thought they'd get away with it, but not after the second one went down. Sociopathic Dennis Muilenburg didn't end up out of pocket.
the Ethipoan report is out now. What say you now Mentour pilot? It looks bad. They had no chance to recover at that high rate of speed.
The best aviation channel, bar none.
Questions I'm hoping the FAA will be asking in addition to the standard ones. 1) Why did those sensors fail? Is there a flaw in the design or manufacture? How often do these sensors fail? 2) Are there any other systems on this aircraft that rely on a single input - critical or not? 3) Is MCAS integrated into the flight control computers or a separate system - if it is separate is it possible for the pilot or first officer to disable or reset MCAS?
I would add 4) Are there any other systems, functions and or alarms that would have activated or de-activated as a result of that sensor fault that would have contributed to these accidents, apart from MCAS?
As a MAX driver myself, what about the stab cutout switches and fly the plane first. There’s been no mention in the press that Lion air had the same problem the day before and they used trim cutout switches, manual trim. Easy to say since I do have the advantage to Monday morning quarter the situation.
Dane ... Holy crap.
Like you're the only person so far today & most days lately that I've come across that seems to be aware of the MAGA / free press Juicy Smellitt schwindle being perpetrated against Boeing.
Not a single member of the bloodthirsty Boeing carve-up mob that I've challenged knows about the PAN-PAN call the day before the doomed Lyin' Air 737 MAX took a swim ... not to mention the unchanged since Day 1 in 1967 and likely to remain unchanged till 2067 process for a 737 pilot to actually start flying their plane.
_
I see the lack of AOA sensor redundancy as a severe design flaw, especially since the second AOA sensor was installed, anyway.
To keep knowledge of the MCAS system from the pilots just to reduce conversion training costs, however, verges on being criminal negligence.
The criticality of the system was high enough that it should have required redundancy by FAA policy per the Seattle Times report. How it does not have redundancy and still got approved is apparently not yet available. I suspect the FAA and DoJ are looking at that pretty hard.
Boeing provided data from NG flights that demonstrated the required performance for prevention of engine-driven pitch up. Since the FAA had no responsible representatives present at Boeing they accepted the data as proof of performance for the augmentation required for the new engines. Only Boeing and the FAA know why Boeing's proposal to use only one AoA sensor for what was to become MCAS was accepted as sufficient. We know why Boeing did it. It was all about the "less than an hour train for the new certification" sales pitch. It takes a very strong CEO to face the facts and say NO.
@@henrydelana9317 Speaking of CEOs, the one from Ethiopia Airlines ought to have his tail set on fire. He allowed a 200-hour pilot to sit in the right seat.
That's no better than having a single pilot in the left seat and one of the passengers from the back sitting in the right seat who just got his private pilot's license.
As Capt. Sully said: "It's abhorrent" to have a 200-hour pilot as a crew member. The CEO was trying to save money by getting young eager guys to build hours at the expense of the 180 people who died due to lack of education. The fact that the prior evening flight crew experienced the same problem but didn't advise the following crew really burns me up. Luckily, the crew the night before had a pilot sitting in the jump seat who knew about the two trim cutoff switches. Otherwise, the disaster would have happened a day earlier.
@@daffidavit, you are confusing the Ethiopian and the Lion Air crashes. The Lion Air aircraft had the same problem on the previous flight, spotted and solved by the jump seat pilot. The problem WAS written up and the AOA sensor replaced before the fatal flight, so the failure was most likely in either the wiring or the computer input channel. At this stage in the B737 Max saga, few pilots knew about the MCAS system as it was not included in the conversion training.
The Ethiopian 200hr pilot: In the past, it has not been uncommon during pilot shortages to hire pilots with the ink on their CPL licences still wet. This may be rare among major carriers, but this is simply a matter of company policy, which is usually changed to suit the new pilot supply situation, and has been true around the world. There is no indication that this low aexperience had any bearing on the accident, in fact this pilot must have just come out of the rather intensive initial type training on a regular B737 flight simulator, so he was most likely quite competent.
@@Halli50 Thank you. I did confuse the Lion Air flight, so I have to take it back about the failure to advise the next crew on the Ethiopian flight.
But I still agree with Capt. Sully, it was "abhorrent" to put a pilot with only 200 hours of flight experience in the right seat. I don't blame the pilot. Any young guy would jump at the chance to be a first officer in a 737 MAX.
But the CEO should be held accountable for not training the Captain on the MCAS system, especially since it was known from the Lion Air incident and other NASA voluntary pilot reports that the trim could go into a runaway situation.
Finally, the Colgan air disaster near Boston taught us that flight experience can mean the difference between life and death. When there are many people sitting in the back seats, they expect and deserve the best. After the Colgan disaster, Congress made the FAA change its regulations to require all major airline pilots to have at least 1,500 hours. The Captain must have an ATP rating. And if the captain is over a certain age, the pilot in the right seat must also have an ATP. I respectfully disagree with you about a 200-hour pilot coming out of 737 sim training being competent.
As Capt. Sully said the crew must act as one. They have to be able to almost read each other's minds and act accordingly when there is an emergency. No 200-hour pilot is that good. The passengers deserved the best pilots not, as Sully said, one pilot and an apprentice.
Thank you for correcting me..
Don't be so insulting. Civilian and military pilots are both fully aware of AoA. Stop apologising for Boeing too Also you assume MCAS gets bad data from the AoA sensor, but all indications are that MCAS actually misreads data and then goes on it's merry way. Every 15 seconds. Boeing would absolutely love this thing to just be an AoA sensor problem...but it isn't...
well: a flight incident is never "just a technical problem". It is a rabbit hole with many contributing factors. Who approved a system that: Relies on just one sensor? Why does it not cross check with other sensor types? (Attitude indicator, Air speed, ...) Who authorized such strong control inputs by MCAS? For the intended function and situation a few degrees would have been enough. Why did maintenance not realize that the AoA sensor was defective? Why where the pilots unable to find the relevant checklist item? Is the checklist not structured correctly? Is the manual missing information? Is the training inadequate? Should the 737Max have been the same type as the other 737?
@@sarowie The pilots of the planes that crashed were too close to the ground to have time for a checklist..
@@iBreakAnkles4Fun Runaway trim is a memory item. You are supposed to know what to do without a checklist.
I. Runaway Stabilizer
CONTROL COLUMN - HOLD FIRMLY
AUTOPILOT (if engaged) - DISENGAGE
Do not re-engage the autopilot. Control airplane pitch attitude manually with control column and main electric trim as needed
If the Runaway Continues
STAB TRIM CUTOUT SWITCHES (both) - CUTOUT
If the Runaway Continues
STABILIZER TRIM WHEEL - GRASP and HOLD
@@iBreakAnkles4Fun That checklist is done from memory, so yes they should have had time.
It’s nice to have an actual pilots point of view on this. The media has blown this way out of the water
Most of them would not understand what AoA is either, never mind the implications for lift etc.
Boeing's corner cutting gambit has cost lives. The engineers will be fired, and the executives will get bonuses for steering the ship during difficult times. Even though the decision to reengine the 737 was made by the c-levels to change the 737 flight characteristics using a bigger diameter turbofan and then cut costs by insisting that no retraining was necessary.
First question, your response is only partially correct. The AOA display may not be necessary for safety but the disagree indicator is necessary for safety. If you had this indicator before the software upgrade it could have told you to disable the Auto Trim before your plane took a nose dive. Even in the event of emergency the warning light could have pointed you in the right direction to disable the system sooner. Especially if Boeing had told you about the MCAS system and had a procedure that directly told you to disable the electric auto trim if this indicator is on. If they had told the pilots about this system and had a procedure for it many lives could have been saved.
If you are a pilot and have to have an indicator light to know when the trim is running against your input on the yoke, I have zero interest in flying with you. Boeing had warned the Ethiopian pilots about MCAS and reminded them of procedures. Maybe you're right--maybe they needed an indicator. Are you sure you want to go there?
If the 737 max is a very stable AC ,as you are stating , then why did they have to install a MCAS function on this version of 737 ?
I can imagine this scenario in 2011, when Airbus was launching a new AC that would take some major market out of Boeing. Boeing had to react super fast to keep their market share, so management probably put huge pressure on their advance design team to come up with a quick solution. A complete new AC would of taken to much time so they decided to tweak this low landing gear AC design, with the biggest engine bypass ratio , in order to compete with the Airbus Neo fuel economy.
To keep the engine ground clearance they had to move the engine forward and raise the forward landing gear (it was not possible to raise the main landing gear without a major redesign of wing that would of require a new AC certification which would of taken more time to market ) . This and the much larger engine nacelle create a condition at high AOA were the nacelle provide unwanted lift that can tiger a positive feedback looping and stall the aircraft in the most critical part of their flight plan. I am not a pilot but I dont think that with a max loaded aircraft in climb it is possible to recover from a stall.
The failure of the FAA to scrutanise Boeing and prevent them from taking shortcut to beat their competition , is IMHO the cause of these two AC catastrophe . The US corperations controled the governement into eroding the authority and understaffing the FAA so they can have a clear path to profits. They also control the MSM and I can't help to wonder if , with all the money which is at staked here , that you are not being compromised in your evaluation of the safety this 737 max.
I am very pessimistic about the future ,because other goverment watch dog agencies like the EPA and FDA and Atomic energy may be in the same situation as the FAA and could result in much bigger catastrophe the those two crash.
There are three broad types of (in)stability: 1. Positive stability where every disturbance returns to the previous (normal) position. 2. Neutral stability where a disturbance remains in the last position. 3. Instability where a small disturbance rapidly accelerates into a runaway condition.
The B737 (along with all passenger aircraft) stays within positive stability in all phases of flight. MCAS is only designed to deal with a small deviation from the acceptable rate at which the aircraft returns to the previous (normal) condition. This is a certification requirement regarding the feel of the pilot controls in manual flight, and was never related to (in)stability.
The answer you describe is melodramatic journalistic shorthand for a much more subtle concept. The rest of your comments are incorrect.
I love his level headed, rational explanations.
Sure, I guess. But he pretty much ignores all the dead people from two accidents due to design flaws in the Max.
@@gfuterfas So Graham, if you were trying to understand what happened and how to prevent further accidents, what would you do about the dead people?
@@buffdelcampo Obviously, you can't do anything for the people killed by the accident, and I am a big fan of this channel, but I do think Mentour could express a little more gravity. It's not like an iPhone update that Boeing is releasing -- this likely caused two crashes, and after the first one, they were already working on the fix while allowing their aircraft to fly. They were also apparently allowed to self-certify the safety of these aircraft by the FAA, and I think there should be some outrage expressed. How can he say that he thinks it's one of the safest airplanes in the sky if the certification process is flawed? I heard on the news that the FAA can't afford to hire the necessary people to do the safety certifications, so they allow Boeing to do it themselves, which obviously has a conflict of interest. It's more than just a "PR Nightmare". The sad part is that the grounding of all these planes is costing the airlines (and Boeing) tons of money, so there will probably be a rush to lift the ban on the 737 Max. There's so much pressure to have a hasty update that could still have problems, and the full accident investigations may not even be complete.
@@gfuterfas Instead of watching the idiots on the news, dig into this. Do some real research. Most major manufacturers self certify. It's been that way for at least thirty years. So how many airliner designs are self certified? Probably all.
Ethiopian Airlines crew in Boeing 737 crash "could not control" jet despite following procedures, report finds!
Read more than the head line, they didn't follow procedures.
Eric Bedenbaugh yes they did
Eric Bedenbaugh yes they did! You stupid ufck!!!
@@1969bogdi Read the entire report. They did not!!!!
@@ericbedenbaugh7085 - the Ethiopian crew did follow procedures after three cycles of incremental (and un-wanted) stabilizer movements initiated by the MCAS. The crew turned off both switches to remove power from the horiz stabilizer motor, then attempted to manually change the stabilizer position by using the control wheel in the cockpit, as documented in Boeing's procedures following the Lyon Air crash. Current hypothesis is that because they were also honking back on the stick in an attempt to raise the nose of the aircraft, the limited mechanical advantage of the small stabilizer control wheel in the cockpit used to move the stabilizer was not enough to overcome the extreme forces on the stabilizer of the aircraft which was now exceeding the design limit of airspeed as it dove toward the ground. The crew realized that the frozen control wheel meant a certain crash, so they re-powered the stabilizer control motors, and attempted to use the thumb switches to correct the horizontal stabilizer position, but by then, it was too late.
Boeing is in deep doo-doo with this woefully poor design because:
1) dependent on a single point of failure (one AOA sensor) for a critical response (nose-down correction, even at low altitudes)
2) no diagnostic checking of AOA sensor function visible to pilots on aircraft without the optional package to do so (which clearly says that Boeing realized this was necessary, but decided for some really strange reason to charge extra for it)
3) No feedback loop between Horizontal Stabilizer and MCAS - so no matter how 'smart' the MCAS software is, it couldn't tell that the Horizontal Stabilizer was already moved to a dangerous nose-down position before moving it further
4) inadequate manual backup for pilots to move the horizontal stabilizer under several flight conditions (something well known since the 70's - pilots used to be trained for this, but for some reason are no longer trained for it)
5) the "emergency" cut-off switches should provide the option to just turn off MCAS, and not the entire power to horizontal stabilizer motor, so that the pilot can make corrections to the stabilizer position using the thumb-switches provided for that purpose. Older models of the 737 had this - one of the two switches would disable auto-control functions but leave the power to the stabilizer motors "on". Why that option was removed on the MAX will no-doubt be discussed at some length in upcoming lawsuits.
The pilots was helpless,fighting against the system..which switched on 4 times..that wasn’t lack of skills ,that was something else
You appear to accept what Ethiopian is saying. If this came from the NTSB, or the BEA, or the AAIB you should consider it as well thought out. It may not be fact (many air accidents are never truly understood, M370 being a classic example). Do not assume that an airline operating a plane that suffers an accident that claims the lives of all souls on board can be trusted to tell the truth about what happened. Ethiopian will have to demonstrate that it's pilots were properly briefed on the MCAS after the FAA directive went out in 2018. There are good sources of information about what is going on. You should seek them out.
That was HAL9000 taking action on it's own lol xD
JK, yes the preliminary report are out, and the investigators said that the pilot already followed Boeing AD procedures, but still can't help them out of dangerous situation leading to the doomed flight, this should put to rest Pilot lacks of training as well, since they were aware of the MCAS after Lion Air, they also have been noticed about how to deal with it by following the trim cutoff procedures involving MCAS runaway.
Idk about others..but if the Pilot did knew about what caused the nose down then followed by the correct procedures on how to dealing with it based on the manufacturer checklist but still can't save them out of the dangerous situation, to me the blame isn't on the pilots..it's something else...
Read the report, and the FDR data and CVR transcript released today. Is very clear.
Gordon Richardson -According to reports the pilots switched off the “Anti -Stall”system 4 times in 6 min.but the system turned on every single time.Here:”Ethiopian authorities, in a press conference Thursday disclosing findings from their preliminary crash probe, stopped short of drawing any firm conclusions about the causes of the crash. But they confirmed a flight-control system triggered repetitively during the six-minute flight, pushing the nose down. They recommended Boeing review the system, and said regulators should then test it before lifting a global grounding of the MAX fleet.”
John Smith The press conference was unofficial and completely misleading. Read the report published online.
So refreshing to have a qualified and knowledgeable person talk about this issue.
I’ve been waiting for this one. Thanks mentor!
I hope the answered were to your satisfaction.
Mentour Pilot always! You’re doing a great job of educating me. Thanks again!
What I found revealing in your previous mcas video is that after cutting out the stab trim motor, it takes a great effort to manually turn the trim wheel. Imagine being in an extreme pitch down position, with the pilot needing to pull back on the yoke with great force to counter the trim, it seems difficult to manually trim back within the short time allotted before zero altitude.
Add to that the alarms blaring, potentially lessened situational awareness with the pilot monitoring pouring through the manual to find the resolution, i dont see how they can recover the stab trim manually at such low altitude.
You are very right! It takes two people on the flight deck who can exert strength when required. In at least one case that required strength when the plane was inverted. The Alaska Airlines jet crashed when it's stabilizer failed. All perished.
@@henrydelana9317 The Alaska Airlines crash was due to poor maintenance on the Alaska's part to cut cost. The jack screw was actually stripped of its threads because they were not greased at intervals that McDonald Douglas put in their manuals. Also, a Alaska mechanic put in for the jack screw to be replaced, and was overruled by his supervisor on his next shift. So no manual use of the trim system would have made any difference in the Super 80 crash. That was improper maintenance of the jack screw that lead to it's failure, and the crash.
FINALLY...someone who knows what they are talking about. Well done.
The cutout switches are for when the electric assist is unreliable. It's a misapplication that it is the go to solution for automation logic fault when the physical assist functions just fine. It would be like if there was an ABS logic fault in your car the fix would be to disable the vacuum brake assist. Transparently-operating automation should fail safe and not require disabling powered assist.
@@towerrunner496 Hi Tower. Yes you are correct on all points. Did you read the transcripts of the cockpit voice recorder (CVR)? If you did you would have heard the pilot flying coaching the pilot monitoring on a last attempt to flip the plane over prior to impact. Had it worked he might have saved some lives. Unfortunately the pilot monitoring could not reach the rudder pedals while inverted. He was unable to assist in the rollover maneuver that the captain wanted to try. The captain was firmly belted in and able to work the rudder pedals. The first officer couldn't help. Perhaps my choice of a physically challenging experience eluded some. Do you know the name of the Vice President for Maintenance who was fired for this accident? Was you wife and daughter present when the CEO went to Fairbanks for the funeral of a man I knew?
I like your content. I was hoping you would address the question of whether or not there is ultimately a fatal flaw in the 737 MAX design from putting engines that are too large on an airframe that was designed for smaller engines. It has been suggested in articles about the unfortunate crashes that the MCAS system was meant to rectify an aerodynamic design instability created by the positioning of the larger engines.
Bingo!! if a software fix is needed to correct an aerodynamic error the aircraft is unnecessarily defective. What is needed are aerodynamic fences mounted parallel to the longitudinal axis aft of the wing (center of gravity) that will help force the nose down with more nose down pressure the higher the angle of attack. This is an item that is benign at cruise (level flight) and active during climb and descend.
What happens if the electrical system gets crowbarred? (massive short circuit)? The FADEC (full authority digital engine controls) engines account for this with their own power source (alternator) separate from the main electrical system.
In the above scenario pilots will be busy flying the aircraft with one little battery powered instrument in the dark. MCAS won't work then.
I understand the Boeing removed the vortex generators from the wings. These help improve lift at low (stall speeds). If they were needed on the previous B737 what was the justification for their removal from a potentially tail heavy aircraft at low speed?
As Steve Blue has noted (see below - chronologically) … The fact that two AOA (Angle-Of-Attack) sensors were available as part of the design-build is the crucial (and fatal) design flaw in Boeing’s initial MCAS implementation. What ever Boeing’s says (or most telling - doesn’t say) about how safe their revision is, there is no escaping the humbling fact that Boeing and the FAA made an incredibly bad analysis and decision to allow the MAX to fly off the assembly line with a SPOF (Single-Point-Of-Failure) that, as was so tragically demonstrated, caused these airplanes to crash with a total loss of passengers and flight-crew.
Just my opinion but … I feel very strongly about this and hope that lessons will learned and things will (hopefully) change for the better. 🙏🏽
Especially regarding the fact that a similar system that uses input from both sensors, plus indication to the cockpit, was already installed in a military airplane, when military and civilian world tend to give slightly different priorities to safety vs. performance. That´s point one.
Why there even was the possibility that the pilots did not get to know, there was a subsystem installed that could actually assume trim authority in certain circumstances, and how and when and why it does so, is beyond me. If it is true what sensationalist media tell me.
In addition, it would be a nice feature to give some kind of indication to the cockpit that the system has been engaged, so the pilots know what they are dealing with. I fully understand, that de-cluttering the cockpit of irrelevant notifications is a safety feature in such a complex machine, to not distract pilots from flying and let them keep focus and situational awareness. However, my totally uninformed layman´s guess would be, that it would be a nice feature to have at least an LED labeled "MCAS", or, for multiple susbsystem input, "AoA warning, auto-trim engaged", or something like that. If that goes on, the plane essentially says "Listen guys, I feel I need to do something to the trim, because my sensors say, you are about to drop the ball here!", so the pilots would at least know what´s going on, and could react following a) " yes, that´s normal und to be expected right now, please switch off", b) "Oh, woops, we didn´t notice, we were busy, thanks for the heads-up!", c) "thanks for the help, we were getting worried, too" d) "what are you talking about? We are nowhere near the situation the sensors tell you we are in. something seems to be off, stop it!"
In principle. If the reports are true. If it turns out after the investigations, that MCAS was actually involved in the chain of events that led to the loss of lives and 2 airframes, that would only strengthen the importance of your point. The possibility alone should be enough reason for concern.
Paavo Bergmann
I think that the fact they had installed a safer system on the military version is going to be very costly for Boeing. I visualise multi-billion dollar lawsuits sticking to them like confetti to a bride.
@@q.e.d.9112 probably. But then again, hindsight is always 20/20, and what do I know about planes? Also, military aircraft are expected to pull crazy stunts that commercial aircraft wold never think of attempting, so of course they get all the assistance there is.
As an engineer, not a pilot, I have been bewildered by the absence of a system that compares all of the measurements of ground speed and direction, air speed and direction, altitude, position and a lot more, to give sophisticated analysis and alarms when different systems give contradictory measurements. At our current state of technology such automatic comparisons can be done with incredible precision and reliability. We can compare the ground speed given by radar with the one given by GPS, and compare it with the speed given by the pitot tubes, and we can have a simulation of the angle of attack taken from the flap setting, air speed, landing gear setting, balance of loads and so on, that would be compared with the actual angle of attack so that the pilot could get an alarm if they don't match.
Many of the procedures that the pilots do are based on the way the technology worked when computers had a small fraction of the power they have now, and I don't believe the full capacity of these new technologies is being used. Am I wrong?
You probably want to fly the A350, which integrates all its sensors, in a way the B737 cannot possibly do.
Great answers with solid explanations. Unfortunately we live in a sound byte era and anything as complicated as aviation can’t be reduced to one sentence. If you want to understand, you must be willing to listen. I found this video to be very helpful to my understanding 👍
But do you understand an aircraft knows when to nose down but not nose up? I find it strange.
@@sssri1122 the powered trim System can go faulty witch puts the plane into a nose up or nose down
it's why you have to remember off by memory when you have a runaway trim situation, outside of native English speaking seems to be where this issue comes from where they are failing to follow basic runaway trim situation and letting the powered trim crash the plane
which is what happened with the Estonia flight and Lion Air they failed to cut trim and was actively fighting the trim system (witch you should never be doing) by pushing trim back up when the system was trimming back down
I Believe When Boeing are saying that airlines pilots did not have the correct training they may have been referring to runaway trim situation training which these pilots were failing on (not specifically relating to the MCAS system this is just the runaway trim situation which they should be trained for the last 40 years)
ss sri it is due to the design of the aircraft and engine position. It is described better in another video, the engine thrust has a greater tendency to force the nose up in the max variant, thus this system is in place to counteract this in a specific extreme scenario
@@leexgx Ethiopia? Otherwise this would have been a third one...
@@leexgx The "MCAS INCIDENT" experienced is nothing like "runaway trim." I won't fly MAX until it gets CERTIFIED under a new TYPE certificate.
Thank you for providing clarity. Always irritates me when the media puts a spin on things and they don't even know what they're talking about.
It’s nice to hear a real pilot explaining everything. The news took this story and ran wild. Thank you for giving the facts.
How did they run wild?
Have you watched the news? They ran wild because they took the story and started talking about how unsafe the MAX was. Instead of talking with real pilots who fly the plane they just used talking points that were not the whole truth it were flat out false. The new has been reporting how Boeing charged extra for safety equipment. That is not the whole truth. That is how the news ran wild. We need all the facts in a story, not just part of the story.
Reporting on two plane crashes within five months on the same aircraft is not going wild. The plane was extremely unsafe, the way MCAS could cause the plane to crash. It has now been documented that MCAS relied on a single input.
It's nice compared to hearing various aviation experts on the news with more relevant expertise and detailed knowledge of the MAX 8 than pilots who've never even been trained to fly them have? It's not going wild to report the fact that experts are able to foresee situations in which having the AoA disagree light would indeed be helpful to MAX 8 pilots both without this software update and after it. MAX 8 and 9 pilots should have this light so that they know when MCAS is no longer available to help prevent a stall, because in emergencies knowledge that they're more prone to stalling than usual could influence their decisions. Most pilots haven't received the updated MCAS training as most airlines don't have the planes anyway.
@@jacklabloom635 Not especially, at least based on what we know so far. The software did need correction, as items often do in newer models, but when the malfunction occurred, nothing we have seen so far indicates that it needed to be a fatal event. The crews needed to respond to a runaway stab trim event, whatever the cause. That has been standard training on 737s for decades. Other airplanes have similar risks and similar procedures. That is why Mentour Pilot indicated that he had no doubts about the safety of flying the MAX in the future. The media relies on drama and sensationalism and that often means doing less than cautious, accurate, or knowledgeable analysis, not to mention the breathless tones of panic and fear. Spikes in viewership and ad revenue are strong incentives.
Another blunder of Boeing: new information indicates that the Ethiopian pilots followed the procedures set up by Boeing for disabling MCAS after Lion Air crash.
No they did not. That's what the headline said, but about half way down the article you receive critical information. Yes, they flipped the switches to disable MCAS, but the then for some reason no one can explain--They turned it back on!! There is speculation that something struck the sensor on take off--a bird or an object from the run way.
@@ericbedenbaugh7085 there is an explanation. They were in overspeed and low altitude situation with nose down trim. The forces on the horizontal stabilizer was quite high, and the pilots couldn't manually reset the trim (they have to move it in opposite direction of the forces exerted on the stabilizer). Hence they reactivated the electrical system hoping it would assist them. Instead it trimmed even more down and their fate was sealed.
Eric Bedenbaugh because the manual trim was impossible, that’s why! There was nothing else to do. They re engaged in order to activate the electric manual trim ! You
@@norbertmayer7005 There is a pilot by the name of Juan Browne who has a video on this very topic. Sorry I don't have the link but he gives a very good explanation of proper procedure.
MCAS was back on. But are they sure whether is by the pilot or the system kicked on by itself
remember the rudder problem with the old 737's but we fixed it and flew safely so we can say that this situation is just a small bump in the road like before and we will clear it.
Anirudh ... Is there a problem with the apparently unchanged since 1967 in-flight process for a 737 pilot to actually start flying their plane?
_
@@kradius2169 not sure go the mentour aviation app there you will get a better response and i just a kid
Yes love your videos 👍👍👍 today is my birthday 🎂 expecting your dog to appear any moment😂😂😂😂😂
HAPPY BIRTHDAY
Happy biiirthday toooo you, haaappyyy biiiiirthday to YOOOOUU!! 🤩🎂
Mentour Pilot Thank you 😊 😊😊
Happy Birthday @Fun Sisters
Thank you to all of you😊
Stay safe Mentor. If you end up flying the 737Max I’m confident your training will keep you, your crew and your passengers safe 👍
I will be flying it soon and I will sure do my best
@@MentourPilot Congratulations mentour! Wish you all the best and I know you can handle the Max safely. I've seen your simulator training and it was an absolutely wonderful to execute those problems..
I have no doubt that you will be flying safely, because of your experience, m but ALSO because the MAX is already a safe aircraft. You will be flying the safest aircraft in the sky, especially after all the scrutiny after these tragedies. I have no doubt that if you were flying one even before the upgrades, even if you had the same situation, that you would have done your checklist and turned off the MCAS system, and safely landed.
@@MentourPilot
I wonder if there ever are stall situations, which MCAS can handle, but pilots couldn't. At least they would be rare, I assume.
Hi Mentor!
I have never been a fan of the Boeing 737. Still prefer flying the ‘Mad-Dog’ and Airbus. However after looking at your videos, I have a better impression on the 737 system.
Do hope to see you flying the 787 Dreamliner one day! Keep up your great videos. :)
Is it slightly disquieting that Boeing didn’t, from the jump, install the same mcas safeguards in the max as in the military 76 variant?
My question, can such conditions exist that no matter what happens aircraft will stall and crash because of high AOA and not enough speed alone, regardless if MCAS is there or not? These days companies will do anything to save money, including making pilots climb at max rate to get higher and increase fuel efficiency. And also pilots reliant on software/systems too much making them too bold. And it's not like one can practice stalling a commercial aircraft other than in simulator.
@@couldyourewindplease3653 Meh - few false assumptions there. First, airplanes can easily outclimb the limits that ATC sets for them. They actually have to *reduce* thrust to keep from level-busting or over-speeding during a climb. I also think it's mostly a myth that airlines will skimp by encouraging practices that directly flirt with safety. ("I need you at level 340 in *minutes* skipper! You Hear Me? You better be climbing like a Bat Out of Hell!") More realistic/less sexy ways airlines try to save are *slowing down* a flight once it's at cruise, in order to optimize fuel burn, and by contracting with code share partners with very low margins who pressure their pilots to fly lots of circuits back-to-back like the Colgan Air pilots. Or by lengthening the time between maintenance as Southwest is reported to have done. But if you tried to climb a 7-3 fast enough to stall it during a commercial flight, you'd have a level bust from ATC and a visit from the chief pilot way before you risked a stall.
The answer is the one you might guess first. They saved some money, and booked orders based on a risk. Would you want to fly on a plane that was sold this way? My guess is that Dennis Muileburg wishes he had silenced Sales and told Engineering to embed the dual AoA system and make it fail-safe. He could have done it as CEO. He chose to take the more risky approach. NASA did too when it chose to launch the Challenger. Flying is risky. Some risks can be managed, some cannot. Good companies excel in managing risks. If profit ever becomes the driver risk will rise.
Boeing does no wrong as far as you are concerned, even in the face of them clearing erring in developing an MCAS that depends on data from only one AoA sensor. Unbelievable!
Kwame Boadu Kissi he is simply looking at it with a clear view that is not company biased
Both airbus and Boeing have made fatal flaws in the development of their aircraft. For instance with stall susts such and Air France 447, an a330 that killed everyone onboard- airbus quietly pushed a software update after that flight as well that corrected some things they got wrong
He's not arguing that Boeing does no wrong. He's just arguing that he believes they (possibly incorrectly) did not consider AoA disagree light to be a vital safety feature that they charged money for out of greed.
Many thanks for your informative videos.
Regarding MCAS, it seems to me that (1) Pilots should have been told of its existence, (2) that it can override their control inputs (3) there should have been a warning light on the instrument panel that would illuminate or flash to notify the pilots when MCAS is operating, and (4) pilots should have had a simple and easy means to turn off/override the system if/when necessary.
This just part of a larger problem however. In building the airplane, they changed the engines, changed how the engines were mounted on the airplane (changing its flight characteristics), and changed the computer system. Pilots were left out of the loop, and not told about the MCAS; airlines were told that flight crews would need only minimal training to successfully transition to the new aircraft. There was a rush to get the new aircraft certified and flying commercially, and one has to wonder what other problems were "swept under the rug" in the process.
The take-off at 00:50 seems almost vertical. I guess the commercial jets can't do that and that's just the camera angle. Am I right?
If yes, how do they get that kind of footage?
Probably telephoto/zoom lens effect. Most aerial footage is taken from another aircraft or helicopter flying in formation.
So, if the "upgraded" system was up and running in the tanker, why was it not installed in the
Max in that format?
Probably made classified by the military hence not made public.
No not classified at all. But the software build for the KC-46 is secured. It could not be shoved into the MAX flight control model without major problems. Boeing chose a simpler (and cheaper) solution. And now they regret that decision.
When you’re early enough for Mentour to maybe see your comment, but he explains so well in the video you’re left with no questions 😂😂
Hahaha! There are ALWAYS more questions my friend. Have a great evening.
@@MentourPilot Okay lets to Astana on approach to SFO set to Baritone Boogie with Ground Dispatch reading the Spreadsheet for Frieght to Atlanta Harts-field → Roll new Grad from American Eagle ( my chosen flag for now ) → walks from terminal operations; Just slightly proud our featured PM / Observer does not realize this will be the ride of a life-time and will be lucky to keep all his papers in the same Flight Bag 3 days later
777-200 or 300 or any of the later that do not have the MAX issue to confound as literally no-one is going to get corrections via reading the handy manual on deck ♦♦ Not to be even slightly facetious I loaded the hearings on C-SPAN and nothing technical correct was seen so I went back to work with Juan saying that we really at this time just not know if the 2 toggles take the MACS out of the control loop leaving power for the split-trim on Boeing Control Yoke
No comment other than I really enjoy your videos. I've learned a lot. And I have zero involvement in the field of aviation.
Good job sir.
Look, what you said at 7:05 is Huge! Boeing had only to add that one feature in with no redundant AOA sensors and two crashes would have been prevented. That to me is an oversight of the highest degree and you can just throw away the iPad training as a reason of concern. The plane/MCAS did not disengage when contra input was detected from pilot. Even autopilot releases doesnt it when the stick is used manually?
No Dog! No Good! I am here to see them in action! Flight information is Secondary.
You didn't wait for the very end!
A dog makes an appearence at 16:52, at 16:12 two dogs through to 16:26.
Yes! What a teaser at the very end! Ty.
Thank you Mentour for this video. Your explanation about how the MCAS installed in military aircraft has more resilience than the single AOA sensors in the 737 Max adds weight to the argument that Boeing overlooked an important quality issue here. Which is to build quality into the engineering process rather than troubleshooting. I agree that we dont know the cause of the accident and we have to wait for the investigations but these 737 Max 8 aircraft in both recent accidents were falling out of the sky, nose dive into the sea and nose dive into the ground killing all passengers. No wonder Boeing has gotten bad press.
@dothemathright 1111 The MCAS system in both the military application and commercial application are used to stabilise the aircraft so they have a common purpose. My point is that building redundancy in to the 737 MCAS is just as critical for passenger safety and preventing airplane crashes that lead to loss of many lives. Thank you.
Awesome video!!
Thank you!
I'm just an electrical engineer with some computer and programming knowledge - I still can't wrap my head around the fact that MCAS in the 737Max did *not* check the inputs of both sensors (aka redundancy), and that overriding it was made so hard. The more so when the military machine had both things in place (and it seems to work there). It would be interesting to know what decisions lead up to this situation. I would've thought that in the aviation industry cutting corners would be a big no-no, because lots of lives are at risk, not only reputation …
I can't defend the decision, but it seems that it was a late-stage add-on following some unexpected flight test results. The computer system architecture of the B767 (KC-46) and the B737 is not the same, so transferring the software and system parameters may not have been simple. Then finally someone cut corners. It was never a planned and carefully thought out system.
I have so much respect for you Mentour. Pilots like you make commercial air travel the safest way to travel in the world. Having said that, I do have an issue with something you said. At 1:40 in the video you make the statement that “when Boeing builds aircraft, they want to make sure that it is Fully safe to fly”. I think even you would be forced to admit, that if this statement was “Fully” true then Boeing would have been sure to equip the 737 with the same safety features regarding MCAS as the KC-46 Tanker sold to the military. It is dubious, at best that Boeing would think it necessary to create the redundancy’s necessary in the KC-46, but not the revenue version of the 737.
A really good way of thinking about this issue is to start with the fact that somewhere deep in the basement of Boeing’s engineering department, a really thoughtful engineer, imagined a very similar scenario that the Ethiopian Airlines flight crew faced when they were trying to wrestle the airplane away from the evil MCAS. These people paid for it with their lives sadly.
I guess what I’m trying to say is Boeing had the solution for the problem, before people died. Only the deaths resulting from these accidents, has prompted Boeing to implement the solution. One could argue that Boeing was influenced by an analysis of the probability that MCAS would cause these issues returned an extremely remote chance of this occurring. However, reality dictates that some folks at Boeing thought it prudent to add those safety features for the KC-46. So based on all of this in my humble opinion, Boeing takes very carefully planned risk assessments when they design and build an aircraft, but they definitely don’t always build an aircraft that has every safety feature in their arsenal to make it Fully safe to fly.
I guess the real question is why is this so? Usually the answer comes down to money and profit. I believe wholeheartedly in capitalism. It is the engine that runs the world, and has given us this beautiful technology. This is one area where the government needs to be heavily involved in forcing companies to make flying as safe as humanly possible.
I might be dating myself but I thought the main difference between Airbus and Boeing commercial planes was the fact that Boeing pilots, at anytime could take full authority of the aircraft, negating any automatic systems. The MCAS system seems to invalidate what I was told some 20 years ago. Are pilots, both Airbus & Boeing, getting too comfortable with software?
There are always detail differences between the philosophy of manual control, and the actual safety and stability systems implemented. The B737 has long had something called speed trim, which operates in part of the flight regime (fast speeds), opposite to MCAS (slow speeds). Whether both systems were operating simultaneously during the MAX crashes is a disturbing possibility, with faulty AOA data and not anywhere near stall.
Airbus pilots can take full control at any time.
@@borninjordan7448 Only theoretically. The reality has caused a number of incidents and accidents, as you probably know.
It is a very common opinion in the industry that automation has had a negative effect on stick-and-rudder flying skills. I would go further and say that I think it has probably been causal or contributing in a number of tragedies. However, so far as what you were told about pilots being able to take control as necessary, we have still not seen anything that demonstrates otherwise from these MAX accidents. Boeing has generally maintained more mechanical control connections and backups than Airbus, even within their FBW systems. I have never been rated on the 737 but I still know how to stop a stab trim runaway event on that airplane, whatever the cause of it may be (whether a bad servo motor switch or MCAS, presumably), as it has been common to the model for decades. Other crews who experienced this malfunction, including other Lion Air crews, did not crash the airplane as a result. As for misinformation, the media make fantastic sums of money from sensationalism and public panic due to the ratings and ad dollars which result, so speculating and suggesting the worst even in their ignorance is highly incentivized. It is best to listen only to the evidence put forward by the NTSB and their counterparts as well as discussions among those who actually fly the airplane.
Well said sir.
Fantastic videos as always
Thank you! Glad you liked it!
Always great videos here.
Love watching his videos. He's elegantly, indirectly, without trying to offend saying that the problem were... the pilots. But people died, others are not informed, so it's easy to throw everything on Boeing. I feel bad for them. Really bad. And of course for the families of the ones who aren't here anymore, but that's another story.
For the folks who aren't technical, "redundant" in engineering is in no way synonymous with superfluous, as this video seems to indicate that it is. Redundancy is a safety feature.
Some interesting information & facts. Thank you for sharing.
What do you think will be the timetable for returning the plane to normal service?
Thanks for the detailed explanations.
Did you know how to turn off the MCAS system before the first crash?
It’s a trick question-MCAS cannot be turned off.
@@petep.2092 Yes you can stop it from moving the trim with the stab trim cutout switches on the throttle quadrant
Not being a pilot myself, Boeing’s pitch recovery has always seemed insufficient. From other videos on 737s, I understand it would 4-5 seconds of full attention to unfold the handles of the trim wheel, then several more to trim in optimal conditions (without MCAS trying to make inputs.) So if the computer lost situational awareness, even if prepared pilots reacted immediately, they would be unlikely to recover the aircraft before it lost thousands of feet! Am I missing something? Peter always said you should slap a pilot and take controls if they are taking chances, why allow planes to exist with computers that can do so much damage? This is not an issue that will only affect Boeing, it is an issue of low airworthiness standards all around. Grow a pair and tell the industry if they have a problem!
the only defence that boeing has is if they can prove the MCAS did not activate in both crashes. outside of that, no jury is gonna buy the story that boeing didn't design a defective plane. they can argue all they want, but vast majority of the 737 pilots didnt know how to turn off MCAS, which speaks volumes of boeing's mistake.
How can you keep your good videos up so active? I mean twice a week is insane. Keep it up. I enjoy them very much. Thank you👍
I am sure he has at least 2 doubles 😂
Im trying to figure out how he's been flying jets for 18yrs and he looks about 36yrs old...
Was nice hearing you mentioned by Juan Brown recently (Blancolirio Channel).
Both Lion Air and Ethiopian crashes' FDR points same software error. Publicly released today.
Doesn't your job as a pilot depend on the 737 max 8 being in the air? I feel your opinion is compromised somewhat so I take it with a grain of salt. Boeing Engineers in other parts of the internet, have indeed concluded that the larger, further forward and higher mounted engine nacelles begin to provide extra lift at high AOA pushing the nose up...the very reason MACS is being used to correct it. The problem is they thought MCAS would be 100% seamless, it turned out to be less so.
I suspect he has other type ratings.
I think the problem might have been that once the sensor malfunctioned the MCAS pushes the stabilizer into a nose dive. If you switch off MCAS jack screw motor to compensate you also switch off the entire system controlling the stabilizer? This means that the stabilizer stays in nose dive angle? Does the MCAS software know the stabilizer is not moving because the jack screw motor has been switched off? Does it loose track of where it thinks the stabilizer is positioned at?
How to get the stabilizer from nose dive state into a nose up state after you shut down MCAS motor? Continuous trim from the pilot until emergency landing I suppose? Can the MCAS enter a reset state when motor restarted? Can the MCAS handle motor restart at all? Maybe? That would require MCAS to be able to detect the current stabilizer jack screw position on motor startup and go into a default state. If MCAS cannot detect horizontal stabilizer position on motor startup it cannot know what to do, even if a faulty sensor fixed in the mean time.
This could also mean every time you restart the MCAS motor the software could "authorize" the jack screw to move the stabilizer a certain amount of degrees again, possibly past a maximum amount that it forgot because of the restart? So every time you restart an MCAS motor under faulty sensor, it adds another 5 degrees to nose down or something. That is a very scary situation.
These are all possibilities that I have not heard proper explanations for. If I was a pilot, those are the questions I would worry about.
I just found your channel and I really enjoyed it.
Just like the DC-10, it took many crashes to work all the bugs out. The 737 Max may have been inappropriately certified, the FBI is investigating that. So there are higher than normal chance that there are other bugs that have gone unoticed. I'm not going to fly in a 737 Max until at least 5 years later (if they have no additional crashes).
Well, I hope you don't plan to fly at all since every year some plane or others crash.
I avoid flying when I can, but for international flights I have to fly. Usually they are on 777, 787 or A380. Which all have pretty good safety records.
Now, the Wall Street Journal wrote, by information of a Ethiopian investigation insider, the pilots had 4 times the electric switch because MCAS disabled like Boeing said, tried to trim manual by the wheels like You demonstraded in your Video, and reactivated because it seam, the pilots wasn't able to get the machine under control by manual trim.
Can it be, the Max is to difficult to trim manually?
Great question!
The answer is yes, all models of the B737 are difficult to trim manually (see Mentour's previous video). However the MAX and MCAS is the only case where this has become a safety critical situation.
It becomes more difficult when you still have the throttles in TO and not pulled back to cruise/climb and you are constantly getting overspeed warnings because of your excessive airspeed at a low altitude in very dense air....
Boeing "oops" omission and failure to provide needed redundancy could have led to over 330 deaths. If negligence can be proven, the persons involved should face criminal charges. If final investigation reports indicate Boeing's negligence, the company shall pay the money for damages to the families in accordance to it's size and value. If it's proven that FAA has "outsourced" the certification to Boeing itself (!) also FAA should be prosecuted. Lot of "ifs", but I rely on information available to us (public) which is at that time very scarse. Thank you Mentour on putting some light on it.
Excellent video! To those throwing shade that he sounds like he's covering for Boeing, I disagree. He's separating the hype from the facts.
Boeing not putting a redundant sensor and not making sure that pilots understood this system was indeed inexcusable but he's not addressing that aspect of things in this.
What I gather from this is that with a redundant sensor and full pilot knowledge of the system, there is nothing particularly unique or risky about this plane or this type of system.
The media and the regulators should be going after Boeing for their behavior as two very avoidable crashes are on their hands. But Mentour is not addressing that. He is just separately saying that where we are now this plane is as safe as other airliners. If he didn't he wouldn't want the risk for himself or fellow pilots.
I appreciate hearing this sort of info from him versus a journalist or politician.
Hey Mentour, quick question. If the alpha vanes are situated along the longitudinal axis of the aircraft but on opposite sides of the fuselage, wouldn't the readouts on the AOA indicator disagree in an ascending or descending turn, or at any pitch attitude other than zero with a given amount of bank angle established (e.g. maintaining a heading in a crosswind)? Love your Channel, would be thrilled if you answered this question in a video! Keep up the good work!!
Chris Odom just my non-expert guess:
The difference would be slight and predictable. I would assume the program has parameters to distinguish between normal and unwanted maneuvering.
Chris - Although the alpha vanes are on opposite sides of the airplane, they're on the fuselage not the wings. Even in a turn the air on both sides of the fuselage should be the same (assuming the airplane is in a "coordinated turn" and is not "skidding" or "slipping" sideways).
Realistically, there is going to be some margin for error programmed into the system, so it won't show a "disagree" unless the two vanes mismatch by a certain value or greater (perhaps something like 2 degrees' difference). That would allow for minor variations in calibration, airflow over the fuselage, and things like turbulence to cause momentary discrepancies that won't be so large as to cause a "false alarm" that one of the vanes is reading incorrectly.
@@noelwade Makes sense to me. Thanks for taking the time- it had me scratching my head
Yes, therefore as Mentour stated, MCAS will not engage if there's an AoA disagree of >5.5 degrees.
I think it is surprising that any competent pilot would sit there watching the trim system spin out of control and not think to shut it off. We try to design idiot-proof planes with features like MCAS and some pilots seem to forget even more about flying.
it's likely that there were more problems than just one and that could have caused confusion and there was only a VERY short time to sort it out, so we shouldn't judge people if we know only some fragments of the situation where we haven't been ourselves.
@@mattesrocket lion Air one they had plenty of time and they was actively fighting the powered trim system when they should of turned it off and gone manual,,
But after this update(when they are back in the air) the system will operate the same as the boeing tanker variant of the MCAS antistall system (if you pull back in opposite of what the MCAS system is trying to nose down the plane it will now automatically disable MCAS anti stall trim down without you having to stab the trim (cut power to trim) it will also have redundancy on the sensors so less likely to have one sensor trigging antistall MCAS and stick shaker
Reason, the NTSB has made note of this in the past, that the feel the increased automation and control by computers, has had a tendency to reduce pilots ability to react and respond correctly to issues that occur when the automated systems fail or something happens outside their control authority . In essence pilots are losing their perishable skills to fly the plane manually in adverse conditions.
Also there has been some mention of witnesses seeing smoke and debris falling from the plane just after take off, and some data has seemed to show they tried to rotate early off the runway poss due to a faulty speed sensor, which may have caused a tail strike and damage to the plane
@@GNX157 Boeing does not want that it to be that way when a situation happens, I am not sure what was going thro there minds (who ever authorised this badly thought out way to stall recovery) the press love to find holes they can poke at when they think basic safety features are missing when they are not even there on past planes not safety related
now it's going to operate the same as the Boeing tanker version, watch all of video for it (or last 2 minutes for it)
on the other hand Airbus are taking the automation too far and putting inexperienced or even experienced people into there planes and crashing them when something goes wrong (and they still blame the pilot for the crash) basic things like force feedback is missing on the joysticks on Airbus so you have to follow instruments completely to make sure the plane is doing what you expect it to do (as you can't feel it on a Airbus)
Question: I'm aware that you support Boeing, but are you paid by Boeing? How can you possibly make excuses for something so inept, bordering on evil?
Maybe because the media's tales to generate that reaction from you aren't entirely true...? Ever thought of that? Ever heard of the Toyota unintended-acceleration scandal? It cost Toyota billions, they had to make a few changes, but what did later analysis show was the biggest factor? Engineering or media hype? Ever heard of the media trying to demonstrate the danger of GM truck's side-saddle gas tanks? Were they honest then, either? When someone makes money from your reaction, they are going to tell you a whopper of a story every time they can. You would take their tales over all the pilots and engineers involved in these aircraft? Why would any of them have to be paid by Boeing to tell you the truth when their own lives are the ones that will often be at stake flying them far more often than any passenger's life is at stake riding in them?
And this is why I hate media. They should be required to fully watch videos like this and NOT take them out of context before reporting any of their stories.
15:55 Finally - more dog 🐾 show than ever ✈✈✈
As always - fantastic! Very informative videos!
Thank you! I’m so happy you like them and find them interesting.
It is incredible how Mentour defends Boeing stating that he is confident in the safety of MCAS once things get sorted out... Yes, MCAS issues will be resolved. But never forget why it came to the problem: Boeing wanted to sell fuel efficient airplane. They added new engines to old airframe, and made an efficient flying brick. In order to make it fly more or less "safely", they added MCAS. In order to sell it, they hushed up even its existence... You follow me? It was criminal negligence for the sake of profit. How Mentour can affirm that he will be perfectly safe flying it? How many more hidden issues (not MCAS related) may be lurking beneath? If the design philosophy puts sales pitch (no training, fuel effciency) before safety, the airplane is flawed.
You are 100% correct! This video was saying pilots need zero training and all aircraft are alike. This video is to cover Boeing, not the satefy of it's passengers!
MCAS was added becausr the aircraft was unstable! Too big of an emgine for this aircraft. But, it's all about $$$$. Rather than create a new aicraft they just added features to a 1967 airframe!
Poor design! Poor Safety!
Greed killed over 300 passengers!
YES. The problem is not there was a mistake in the design. All aircraft manufacturers make them, and airplanes fall from sky from time to time due to these mistakes. Here the problem is the design philosophy. And much worse, after the first accident, Boeing most probably knew pretty well that their system is in trouble, but hushed it again, hoping that they would be able implement the software updates "under the cover of darkness" so as not to inflict PR damage...
"They added new engines to old airframe, and made an efficient flying brick"
This statement alone tells me you're arguing based on ignorance.
@@fixpacifica I beg your pardon? What part of my sentence is beyond your grasp?
@@michailbelov6703 I have worked at several aerospace companies, including Boeing. I have a bachelors in computer science and a master's in industrial engineering. I was in the US Air Force. I was also a private pilot. It's clear to me that you have no knowledge of the engineering aspects of why this happened, and you're falling back on what most ignorant people do, which is to focus on finding a villain. There are no villains with evil intentions - just overly-confident engineers and management.
Looking forward to seeing you at the Aero Expo in Friedrichshafen! 🙂
The fundamental problem that everyone seems to want to ignore or fail to understand, is that to produce the 737 MAX, a new and larger engine was required. That its larger size meant it has to be placed forward and higher than the position of the previous design. As a result this alters the centre of gravity of the whole design, and unbalances the aircraft constantly. Never mind the problem of altered aerodynamics ! Everyone seems to think that a software package called MCAS is the solution. But no matter what MCAS may or may not do in controlling the position of the flaps and or rudder, this does not remove the fact that the plane is constantly unbalanced. It only means that the aircraft's control surfaces must now constantly fight the imbalance of the aircraft for the duration of every flight. How long before the constant increased stresses on the airframe, and the moving flaps & rudder etc, result in metal fatigue and "bits falling off" ????????
Again a very well done video about airliners. Amazing the press could ever get anything wrong in reporting on aviation. :) We also do not navigate with iPads but the iPad might have the digital chart on it. Yes pilots use iPads for learning about the aircraft, and before iPads we used paper books, large pictures, movie projectors and overhead projectors to learn about the aircraft. But we still use real aircraft or simulators to learn how the fly the aircraft.
I think it is accurate to say that all jet airliners have AOA vanes and AOA is used by the aircraft systems, but pilots who fly the aircraft do not need to have an AOA indicator to fly the aircraft safely. We had the AOA vanes on the 757 and 767 that I flew for 20 years and never had the ability to read actual AOA in the cockpit. We could indirectly have an idea of AOA with some of the indications but could not know what AOA was at any given time.
Look like very oriented answers. As we know now that MCAS was activated during the flight of Ethiopian Air too, there is no time to argue.
You says: "737Max is the most scrutinized". Well, this is irreconcilable with reality. What is the reality:
- some software designer write a critical code with multiple flaw: use of only one sensor where the is two availlable, repeatedly trim down, take over the pilot, and change of directed sensor each flight making error detection harder.
- some other / same software designer create an optional warning system for AoA discrepancy without notifying the risk of MCAS.
- some boeing reviewer did not catch the issue.
- some FAA security scrutinizer did not catch the issue.
And i do not even account for questions like: why MCAS is in the glossary of the 737 max pilot manual without being described in the text? Why north american cie got the AoA discrepancy warning installed and non-american ones not? etc etc...
To have such a series of failures in a process clearly indicate that the process itself is failing. It is not an isolated event.
So the question is :
what are the others hidden 'features' ready to kill people in this company planes?
@Mentour Pilot How come in the Airbus, it never had this nose dive issue resulting in crashes when it ALSO has a system that points noise down when the airplane is stalling/going too slow. Why can't Boeing just copy them?
I think it did with a Qantas aircraft that went nose down.
@@sexylawyer8228 I think that was the auto pilot sensor broken or bug but the pilot just disengaged autopilot and gained control easily.
Thank you for your motivation sir
Thank YOU for watching!
2 interesting questions though. 1. The Angle of attack sensors are in use on many planes and do not feed false readings. Why do we suddenly get false readings on the 737max? 2. Is the design of the 737max fundamentally flawed with its large engines positioned forward and higher? That is in the panic to compete with the Airbus A320neo Boeing patched up the 737 in an unstable way that will always require high input from MCAS ? Love your videos by the way.
Many of you understand what our friend Mentour Pilot is trying to convey. Some of appreciate his candor when discussing what has to be the worst airplane manufacturer PR disaster since the Hindenburg. A few of you understand the knowledge that, as a pilot, he is trying to convey. Ask yourself, is this the kind of person I want on the flight deck when my life depends upon their experience? Or would I prefer an inexperienced person in command, one who was trained but may not have learned what they need to know when things go bad (and on the flight deck things can go bad quickly if you don't know how to assess your situation, and then respond according to learned procedures). Panic is your enemy. Mentour knows how to handle stabilizer runaway (checkout the video) so he could have handled the Lion Air and Ethiopian accidents. Sadly the four pilots on the two aircraft did not know what to do. And their flight manuals did not tell them how to handle the situation they were faced with. Blame Boeing first. Then blame the US FAA second. Then blame the US Dept of Transportation third. And, because the safety of the flying public was of no concern to him, Donald Trump, who shut down the FAA when Boeing was ready to move forward for a fix to the problem. Oh, and just remember, Donald Trump's former Head of the FAA left service over a year ago. For over a year the agency has been headed by an acting head, as are many positions in the US Govt under Trump. After the Ethiopian accident, and the embarrassment to the FAA Trump has nominated a new Head of the FAA. There are many facets of the US Government that are functioning in a management void created by the current President. Please factor that into you analyses of what is going in the air safety realm right now.
Henry Delana Good description of the multiple technical and oversight failures!
I mostly agee with you, but went in the mind of the software engineer to use a single sensor to allow the auto-trim to go to full nose down, disregarding the pilot pulling on the yoke, the second AOA, the inertial platform, the gravity sensor all showing that the the plane was going in a regular take-off angle? Clearly a software update can take care of this problem, The question remaining is how many others short cut Boeing toke on this plane.
Now THATS a different question. One I have no answers for
@@MentourPilot Thanks for the quick answer, as for myself it will take a few years of safe max flying for me to fly one of them. Stay safe on the NG.
Great video, cutting through all the ‘noise’
So if the military version of MCAS already had the two critical features they are adding to the civilian version of MCAS then this begs the question why are they different? It sounds like they had already devised the best and safest solution for the military version of MCAS.
The architecture of the B767 flight control computers is different from the B737, so it was not possible to use the identical version of MCAS on the MAX.
@Gordon Richardson I think you misunderstand quantumac statement. In military, MCAS have more redundancy (and all of the sensor needed for redundancy is on the 737 MAX 8 too), in addition the system can be "easily" overridden. Thus when MCAS on civil does not have redundancy, this baffled a lot of mind (and more when we knew that BOEING actually has designed MCAS system which is "safer" in military airplane than in civil airplane. (of course you might say but computer and plane different, here the problem: the basic necessity apart from computer and plane different, it is still the same. MCAS should have redundancy and can be "easily" overridden)
eternalinsignia I understand that point, and am not trying to justify why that decision was made. I was just pointing out that the working and tested system could not be simply copied across two different computer systems.
quantumac The military B767 version of MCAS is not certified for passenger aircraft. Allowing the column cutout switches to override MCAS would violate one of the many technical requirements. Safe and effective are not always the same.
Anyone want to bet against that totally different software teams "designed" the 2 MCAS systems? That's probably where the B-737Max team didn't read the military version specs (if they even could). The civilian team may have only been given a general idea of the military version.
Thanks, for updating. A wonderful day
Excellent video Petter !👌😎
And I loved the puppies bonus at the end 😍!
Thank you Sophie!
I love your new outro