It's impressive. Hard to include the awful sense of jeopardy of a real crisis, though. The screams from the passengers, the panic, the knowledge that if things go badly wrong you WILL die. No reset button. I suppose that's why they pay test pilots so much.
You may have to land a plane one day. Its always good to know & not need it than to need it & not know it. In the unlikely event that this happens youll thank your lucky stars & save your life.
Mentor Pilot proves a very good point. On the Ethiopian crash, they apparently re-engaged the stab trim back on four times to try and regain control the trim as it was impossible to change the trim manually as shown in his video with the high speed. I wonder how many 737 pilots are trained to perform the rollercoaster manoeuvre to move the trim manually with disengaged stab trim?
Kevin Taylor I believe the roller coaster maneuver was out of question for the Ethiopian as the out of trim stabilizers had already overwhelmed the elevators. So pulling on the yoke was futile. Also they were too close to the ground, and did not have the luxury of altitude to perform such maneuver.
Mentour Pilot, I would like to thank you for addressing the question about terrain escape maneuver and for providing further explanation in this subject. You are doing an absolutely fantastic job with those videos. Keep it going and have a lovely, clear sky.
The part I don't understand is why there is no disengage that stops all automatic trim inputs (ex. MCAS) but allows the pilot using the electric motor to trim manually. Car analogy: I touch the brake or shift gears, the cruise control disengages. I can then accelerate, brake and turn manually. The cruise control does not re-engage again. This system as it was built is like a car designed so cruise control can only be disengaged by turning off the engine, losing brake assist and power steering as well.
Great analogy! Spot ON! Only explanation that makes any sense to me is that Boeing ran out of money after paying their CEO & management & shareholders.
Seeing you guys struggling to trim the aircraft brings chills really, only God knows what struggles the crews of Lion Air and Ethiopian Airlines went through
This video is not related to the MAX it shows a feature which is well publicized in manuals and should be fully understood by people flying the aircraft.
I totally understand that it has nothing to do with the max accidents but still it brings chills, knowing what the problem is and knowing how to fix it yet you can't because of aerodynamic pressures, very chilling
Would it make sense in a situation like this to triple-gong the purser so he can work on the captain's side handle of the trimwheel while the captain handles to control column?
What's the red button you mentioned? Can you do a tour of the behind the scenes parts of the flight simulator machine? I think that would be fascinating.
I heard in a video somewhere, at some point, that it's bad luck to let the simulator crash. I presume the red button is a stop button. If you are certain the plane is going down, there is no point in letting it play out, and hence, bad luck.
Ah, please show us the roller-coaster maneuver. It would be epic and since it's not been taught anymore, I'm sure everyone will find it very interesting. Also thanks for uploading this video and giving us a taste of what was in the deleted one which I couldn't watch. Thank you for everything you do. I'm not a pilot but I'm a scientist so I find plane fascinating in their complexity and ingenuity. So all the sims you show are really fascinating to me. Thanks again.
That was an Absolutely Fantastic Video!! Great explanation at the end of why you shouldn't turn to avoid terrain if you don't have visual! Great Stuff!!
EveryTypeOfVideo - Hi! Yes, you're right. Instrument training is bizarre. The cockpit's blacked out completely, so you can see absolutely nothing but your instruments. Learning to rely exclusively on them when you have (literally) zero visibility is enormously difficult and utterly non-intuitive. It feels totally unnatural. Your senses are screaming at you that you're banking, or diving, or climbing, or even completely upside-down, but you have to ignore the urge to try to make sense of things. It's very hard to trust instruments alone when flying blind, but it's even harder to reject what your body's telling you to do. When up feels like down and left is 'obviously' right, you have no hope of avoiding disaster without the right training.
My flying is limited to a Cherokee 140 where trim is "small", simple, straightforward and obvious. This video put the "big plane" trim in a different perspective. I had no idea that trim could become such a struggle. I learned a LOT from this. Thank you!
Thanks for great videos. I would have enjoyed you getting out of the mis-trim as if it were real and also telling us about the altitude loss as it was going on.
Looks to me like the method of applying force to the trim wheels could be designed better, something that gives the pilots more leverage. Seems very clunky, and in an emergency situation could be downright dangerous.
That rollercoaster maneuver is similar to reeling in a really big fish.. We also had a recent tragic loss of life when a local pilot here descended into IMC and lost situational awareness with terrain on 3 sides, she added power to climb out, but also entered into a circular climb pattern where during the turn she struck one of the mountains and perished. Had the turn not been initiated, it was estimated she could have avoided the peak that she struck. Hindsight does have 20/20 vision, but a turn into the unknown when disorientated near terrain is certainly maximising your risk.
Reminds me of the time I took off from Palm Springs in a Cessna 172. There's a mountain on runway heading, which I had been told to maintain, and I felt like departure had forgotten about me, as I got closer to it. I finally asked, "can I turn?", and they said, "Yes, assume own navigation". I turned!
I know this might sound crazy, but if you can’t trim because of aerodynamic forces, get some passengers to move temporarily. In the scenario demonstrated, have 8 to 10 passengers in the front row go to the rear galley. That will move one ton from the front to the back. Obviously this is dangerous for the passengers, but it’s better than losing control of the aircraft and crashing. The roller coaster makes sense, but if your altitude is too low, then you can’t do it. The only option left is to move the CG, to unload the stabilizer. If you need to add nose down trim, just invite any pilots to visit the cockpit and I’ll be there in a jiffy. The passengers will just think it’s professional courtesy, but I’ll know you need help (because FAA regulations prohibit passengers in the cockpit) and you are deviating to save the flight.
Mentour Pilot, I have been made aware that the excessive force required to manually trim the horizontal stabilizer on the B737 goes way back to the first airplanes and at one time Boeing had a flight manual procedure on how crews were to deal with it. So why didn't the FAA demand that Boeing redesign the system to correct the problem? Was it because up until the Max8 debacle it was simply a non issue because the main electric trim system never failed to operate and never ran away and the autopilot servo motor was almost as good? In 32 years working on 737's I only saw one autopilot servo motor that failed to operate and that was because a human removed it's electrical connector before flight and failed to reinstall it. Therefore the crew simply didn't use the manual trim because it was not need until the Max8 debacle which forced the crew into trying to use a system that Boeing and the FAA knew would not work under the conditions that the crew was faced with. In my opinion a chain failures led up to this situation and they are as follows: #1 AOA sensor provides false data to poorly programmed MCAS system #2 MCAS causes autopilot stab trim to run toward full nose down trim. #3 Flight crew treats this as a runaway trim situation and follows the flight manual. #4 flight manual says turn both stab trim cutout switches off and left off. #5 Boeing has changed the wiring on Max8 airplanes so that turning off either switch turns off both motors and also tuning on either switch back on turns on both the defective autopilot servo motor and the good main trim motor. #6 Crew is forced to turn the cut off switches off again and trim the stabilizer manually, which they cannot accomplish and we all know the sad ending.
Mentour, GREAT VID! I can't help but to wonder what happens to a pilot after a missjudgement like in your "terrain, terrain, pull up" video? Does the pilot file a report and if so what then? Thanks.
I turned off notifications from your app a few weeks ago. Back then you got a notification of somthing you said and when clicking the notification I was just sent to your chat channel in the app. Don't underestimate the work it takes tom make a good app. It seems you have so far.
I can see that it is almost impossible to trim any 737 manually further nose-down if the mis-trim is already down. But the BAD situation is that it is IMPOSSIBLE to trim it manually in the REQUIRED direction to save the aircraft, to trim it nose-up. The cranking of ONE pilot can NOT overcome the aerodynamic force that is against the manual trim-up effort. Two pilots would be needed to overcome the limitations of the mechanical (emergency) system. But one of the pilots has to pull the yoke back with all his force and has no free hand to assist the manual trim effort at his side with the second cranking handle. The FAA should look into this too. Why was the 737 NG certified in this DEFICIENT way? The problem was already existing before the 737MAX. Suggestion: The TRIM CUTOUT switches should be changeover switches that disconnect the primary electric trim system that includes the autopilot trim, trim switches at the pilot's control wheel and the electric motor near the jackscrew. When doing the switchover there should be an alternate electric trim system with an alternate (additional) set of trim stitches at the control wheels and a DC-motor in the pedestal which (via a clutch) is able to drive the trim-wheel in the pedestal. The electric DC motor has to have enough torque to drive the (former exclusively manual) system and should be connected to the Emergency DC bus. Second suggestion: FAA should mandate this modification to ALL 737 within six months.
I've done some video editing before and tried to make things look consistent from one cut to another especially where you had to do something similar to what you did, there's always something that changes, the dog teleporting in is hilarious!
I love your Channel and all the information and lessons that you teach me. But I have to say that you're dog is so cute. I always watch it in the background. He/she really loves you!!
Between the advice of "not try this at home" and Patxi's teleportation super power I am speechless..!! Hahah great video as allways, thankyou Peter for this kind of demonstrations, showing the case of something going beyond all limits.
we did something similar with a c-172 sim. the c-172 trim system somehow failed and its stuck full forward. we still did our lesson of 4hrs instrument training and it was really a workout in the gym. we were literally hugging the yoke while practicing instrument flying. it was one hell of a lesson :)
Very interesting. Stressing the incredibly wide speed range of a big passenger jet is vital information for a lot of people who perhaps aren't familiar with aviation. A small plane like a Piper Cub or a Cessna 172 will have a takeoff and landing speed not much different from its cruising speed. So, say, from 75mph up to 140mph (NOT accurate figures, just an example!). A big jet might cruise at over 500mph, but take off and land at only 130 or so. That's a huge difference. Imagine driving a car without power steering at its top speed of 120mph. Then try it at 240mph. Then 360mph. Then 480mph. The steering forces would be incredible, and very difficult to control. Air is amazingly thick, dense, 'heavy' stuff at high speeds. It's more like pushing against water, so it's easy to imagine how hard it must be to overcome a big jet's colossal aerodynamic loads without hydraulic assistance or any kind of 'power steering'.
Not sure what your point is. In the video the elevator control still has hydraulic power assist, which was working well. Power assist always has a taper-off function where there is decreasing assist towards the limit of the movement as well as a reduction of assist with increasing speed. This is to prevent slamming the controls against their mechanical stops with destructive force and to avoid abrupt maneuvering loads that could exceed the strength of the structure or could cause violent maneuvers that jeopardize the mission, e.g. cause a rollover in a car or skidding and loss of traction. The whole point of trimming is to position the stabilizer so it is doing all the work to hold the airplane in the desired pitch attitude with zero force on the elevator, i.e. for a 737 and other large airplanes, the elevator is in its neutral position, lined up with the stabilizer's chord line, with deflection from that position available to cause quick changes in pitch attitude if necessary.
Thanks for showing how the second 737 MAX crashed. The MCAS was working against the pilots with constantly 2.3 units AND on the trim and 100 pound force on the column was induced by a 500kts nose-dive into the ground without any chance to pull up again. I thought "why didn`t they just trim the plane per hand after trim cutout?", and this video explains perfectly that this is impossible. Except for bodybuilders whe urgently need an excessive five minute workout during a steep nosedive.......
The very fact that, at really critical moments, really huge physical vigour is required (and even that my not be enough), shows what a joke female "pilots" are. Here, too, women are a recipe for disaster!
Very interesting, I see the connection here that when there is a trim overun situation the pilots mind in a time of extreme stress especially, defaults to throttles to the wall and pull up as trained for terrain emergencies, which would make the trim over-run manual adjustments almost impossible at high airspeed and elevator, quite concerning
I do wonder why there's no possibility to disengage all systems that automatically trim the aircraft without also disengaging the manual trim using the motor. I can see how being able to physically trim the aircraft is valuable if the motor breaks or can't be controlled anymore but there should be a step in between where only the automatic stabilizer systems are disengaged in my very humble opinion. Can anyone shed any light on this design decision?
Spot ON! You nailed it! There should be a new step in between where ALL auto control systems are disengaged but the jackscrew electric motor remains in play controlled by the cockpit up & down trim pushbuttons.
I was wanting to go to toilet after a big meal and there was a Long queue once, Unfortunately No matter how Hard tried i couldnt apply enough back pressure. I Had to Dump Fuel There and Then !!
That reminds me of a story in my initial pilot training when I was flying a small Cessna cross country (by myself). On those long flights and not having a toilet, I had to use an empty bottle to dump my fluid into. When I lifted the now filled bottle and reached behind to put it back into the cargo area, I had to re-trim the aircraft afterwards. I was surprised that it made a small but noticeable difference.
i believe the newer fly by wire joystick is the oposite of the older fly by cable with a yoke control. Airbus did away with the weight of some mechanicals and replaced them by mostly reliable software logic
I am really surprised they haven't redesigned that manual trim wheel lever. The could make the design to were handle first is a little wider and easier to grip. You can actually lock out that lover and have it to where it can pop up extending the actual lever so the pilot or co-pilot can actually provide more leverage and it will give you more force making easier to trim.
Wow great Explanation... Mentor.. Thanks a lot for your effort. One thing understand from here is you need to know all the physics and the mechanics of the flight control...
Your dogs make me laugh every time! The brown one makes me think of a Steif stuffed animal. I believe that they just enjoy spending time with you on the couch during your talks. So relaxed!
When I was in college there was a prank people in the dorms would play on each other where they'd have some people push super hard against a door while one person wedged as many coins as possible into the space between the door and the frame. This would keep lots of pressure against the door, which was applied to the bolt. The bolt then had so much friction that the person inside could not physically turn the doorknob and so they were locked into their own room.
If my memory is OK to move the stab for 1 degree we need 15 manual rotation of the trim wheel. For 4 degrees - 60 rotation and this will take about 1 minute.
Toriy ... Well, in the case of Ethiopia they hit Stab Trim CUTOUT about three minutes into the six minutes, but hey, why not then rewrite 50-year-old tried & true runaway procedure in mid-air instead, right? (21:33) ... and return the Stab Trim CUTOUT to Normal? _
1 min - this is in ideal situation, if there are no high forces on the stub. If there are forces, as we can see from the video above (some rotations took more than 5 sec from the FO), manual trimming does not help or takes more than 1 min. If you are, let's say, 5000 feet AGL and going down with vertical 2000-4500 feet per minute... I am not sure that any vertical S maneuver may help for 100%. Ideally they have to trim forces first and then use CUT OUT... Ethiopian pilots switched the system back when they realized that manual trim is no help (if I understand properly) Yes, I think the time really has come to rewrite the procedure for the 737 family. I believe, pilots worldwide know about the situation, but looks like they really need a help here from the manufacturer. But again... the authority of the Yoke must be enough even with the is stub fully up/down, isn't it?
An addition to the present manual trim wheel : a small central toothed gear that slides out of the trim wheel's " wheel", on the co-pilot's side; and another handle that can swing a 'worm gear' onto the center toothed addition. Then a small handle on the worm gear wheel turns fast, exerting a very high torque on the trim wheel. Then, the worm gear handle swings away, and the splined center gear pops back flush.
Not sure if you even read TH-cam comments anymore, but I just noticed your nav light pillows on your couch. I think that's neat for a pilot to have. Or should I say, super cool!
I'm really mind-blown. I don't understand why in a big plane like a 737, a pilot should ever be required to use a big amount of his physical strength on the controls in order to move the elevators, or any other flight control surfaces for that matter. An electrical engine that weights about 4kg is able to match and exceed any amount of force that a person can exert with his arms. Surely we should have the technology to do that on such a big plane! Having to struggle with any demanding physical task seems very distracting, and an impairment for pilots that could already find themselves in a high-adrenaline emergency situation. And considering that male pilots already seem to struggle, female pilots could have even more of a hard time coping with that. I can understand that the need to apply more pressure on the control stick can provide some useful feedback information to the pilot, but surely it should be possible to employ some servo-assisting technologies similar to the ones employed in modern car steering wheels, so that the pilot could still feel some pressure on the control, yet they would never have to struggle to push or pull the controls.
He's demonstrating extreme control forces created by intentionally extreme mis trimming of the horizontal stabilizer. Pilots would not do this intentionally on a real flight. Perhaps test pilots in certification flight tests.
I flew a Rollason Condor at Shoreham..used to trim by rotating a large wheel by flaps lever and hands off to see if plane dived or climbed, easy to use and stabilised within seconds. doing final approach used to also operate carburretor heater
Thank you. That was fascinating. One thing I found myself wondering: in this situation, would you consider calling someone else into the cockpit to help the co-pilot wind the captain's trim handle, since you weren't in a position to do that yourself?
No, there wouldn’t be time or a possibility to do that. In any case it would be almost impossible to explain what needs to be done and for that person to access
With the miss trim demonstration , I believe he was referring to the fatal Ethiopian flight without actually mentioning it. With the speed the aircraft was going, full thrust after takeoff, and the stabilizer severely out of trim due to erroneous activation of MCAS, it was virtually impossible to manually trim the aircraft nose up using the manual trim wheels. The roller coaster maneuver was out of question because the elevators were already overwhelmed by the out of trim stabilizers. Also, they were too close to the ground. And even if they were able to move the manual trim wheels, it would have been too late, as it would have taken too long before they could manually trim the aircraft nose up again. And they would have still crashed. So sad.
Mentour Pilot, or anyone who knows, can you explain the EXACT difference in function of the 2 Stab Trim Cutout switches on the various 737 models? A thread / comment on a machinist forum claims the 737NG has the switches labeled as "Stab Trim Cutout" & "Auto Pilot Cutout" meaning that the Stab Trim Cutout switch deactivates ALL power to electric trim motor but the Auto Pilot Cutout disables ONLY automated trim commands leaving the pilots thumb trim switches functional. So the function of the 2 switches is DIFFERENT. As I understand it--- in the 737 MAX what used to be the "Auto Pilot Cutout" switch is simply labeled as a "Backup" for the "stab trim cutout", both switches have the SAME function and are always operated together. I looked at google images of 737 stab trim cutout switches and indeed I see switches labeled both ways but the pics are not necessarily noted as to which plane version they belong to. In all the discussions about those cutout switches and runaway trim I've not heard any case where one switch would be operated without the other, they are ALWAYS moved together. Many comments on the recent 737 MAX crashes have suggested there needs to be a way to shut off the automated trim commands but leave the manual electric trim functional. Some even suggesting there needs to be a BIG RED BUTTON to deactivate uncommanded trim inputs. Can it be that earlier 737 versions indeed have this ability? But the MAX does not?
NOTE: couch pilot the stab trim cutout probably cuts out the switches on the yokes and the autopilot one the autopilot. they're probably always moved together because the pilots are not isolating the fault yet. The "big red button" is probably the AP disconnect switch on the yoke switch is used to quickly cut power to the trim motor. (easer to push) I'm not sure about the differences between earlier 747s and the 747 MAX (again, couch pilot) but I'm pretty sure that's it.
Maybe Boeing should add a two speed wheel control (like boat's winches) in case of high speed manual trim operation) Or require mandatory workout for first officer ;)
there is a trim wheel on each side. Seems the nature of manual trim wheels make them useful in only a few situations (slow operation, lower air speed, surface load). Adding a few intermediate gears could make the trim handles EFFORTLESS, right ??
@@glasser2819 With the right gearing, a hex "nut" on the wheel axle, and a handful of charged up Harbor Freight cordless drills (better buy their "premium" brand to pass FAA muster) with matching sockets on them in the cockpit, that should work fine.
Seems like a second set of electric trim motors not linked to the automation would of been better than a hand crank. Like they say in the GTA 5 avenger mission "who still cranks?"
@Thomas Headley ... Why would the overheads be opened? Doesn't make sense for the maneuver shown. It's not a rapid, violent drop like would happen in strong turbulence.
Okay. Nice video. Now explain how the 737 MAX and the MCAS minimize, maximize, mitigate or aggravate the stabilizer control crisis you described. I just love it when the flight control systems and the pilot get into it over who is really the PIC.
the trim wheels being hard and slow, the manual procedure seems applicable in only few cases for small trim adjustements. As demonstrated in simulator, others "run away" cases when plane level is too far out of trim... very limited chance of success. 😂
An example of when the terrain escape maneuver would have saved a whole plane full of people: Dan Air flight 1008. The pilot chose to go into an extreme bank to try and turn around and get out of the high terrain, rather than just leveling the wings and pulling up while applying full power. The plane impacted terrain at a steep bank angle and nobody survived.
The MCAS glitch caused it to take over the horizontal stab and put the plane into a dive. The pilots corrected by switching off the toggle switches to disable the automatic horiz stab control. Question I still have: Why did the pilots switch the toggles back on? Was it because, with the toggle switches off, the hand crank is also disabled, and so they had no choice but to switch the toggles back on to have a chance of recovering from the dive? Even without the horiz trim way out, why would it be so physically strenuous to manual trim using the hand cranks? There's no motor assist for the hand cranks? It's just old fashioned mechanical linkage?
The mechanical backup system is connected to the trim actuators by cables and drums. MCAS had driven the system to the stops using the electric motors and no amount of manual force could overcome the aerodynamic forces at the speed, altitude and elevator positions existing.
@@paulavery366 Part of the problem on the Ethiopian airplane is that the crew never did anything to control their speed, when the aircraft pitched down. They basically went into the dirt at takeoff power. They also didn't cut out the trim system until the aircraft was badly mistrimmed. As a result, the airplane was flying at or beyond its maximum operating speed, and the pilots could not overcome the aerodynamic forces with the manual trim wheels. They likely turned the trim system back on because they believed that only the motors could budge the stabilizer.....which was true, but they would have needed to do things perfectly to recover. They were likely almost beyond the point of no return. Their only real hope of recovery would have been to get the power to idle, pop the speed brakes, turn the trim system back on and IMMEDIATELY dial in some nose-up trim, followed IMMEDIATELY by again turning off the Cut-Out Switches. If they could get the airplane slowed down and get the stabilizer far enough off the full nose-down position, they might have had a chance to manually trim the airplane......or perhaps go another cycle of turning the trim back on, dialing in a burst of nose-up trim, then turning it back off again.
Would an Airbus in direct law in the same aerodynamic stress be as difficult to trim - clarify meaning elevator force would exceed ability to ovecome stab trim?
Roller coaster maneuver kind of like reeling in a big fish. Dipping the rod to reduce line tension & take advantage of increased slack while reeling in before pulling back up again and repeating the cycle until the result is achieved.
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![ร้อยพ่อพันแม่ - WanMai [Official MV]](http://i.ytimg.com/vi/XY2pNYASEbg/mqdefault.jpg)
"do not do this at home". what a nice hint for us guys flying around in a 737 at home :D
Die Besoffenen Straßenköter Gedenkkanal Exactly what I was going to comment
We are so lucky that he warned us.
Armchair pilots.
It's actually perfectly safe to perform this as shown in the video - no simulator was harmed in the making of the video.
i did try this at home before he warned me - will I be OK?
I am impressed that the simulator reproduces the aerodynamic forces on the controls so realistically.
It's impressive. Hard to include the awful sense of jeopardy of a real crisis, though. The screams from the passengers, the panic, the knowledge that if things go badly wrong you WILL die. No reset button. I suppose that's why they pay test pilots so much.
Yup. It's pretty realistic (I think it is a five axis simulator)
they cost like 20 million if i remember correctly
something like that.@@Infiltator2
I was thinking the same thing ....
We need this to be a series! I could watch these videos 24/7 even though the things I learn here will never apply to me.
You may have to land a plane one day. Its always good to know & not need it than to need it & not know it. In the unlikely event that this happens youll thank your lucky stars & save your life.
Coming back to watch your older videos really highlights how much better your English has gotten! Good job
Mentor Pilot proves a very good point. On the Ethiopian crash, they apparently re-engaged the stab trim back on four times to try and regain control the trim as it was impossible to change the trim manually as shown in his video with the high speed. I wonder how many 737 pilots are trained to perform the rollercoaster manoeuvre to move the trim manually with disengaged stab trim?
Kevin Taylor I believe the roller coaster maneuver was out of question for the Ethiopian as the out of trim stabilizers had already overwhelmed the elevators. So pulling on the yoke was futile. Also they were too close to the ground, and did not have the luxury of altitude to perform such maneuver.
@@eudofia how is Boeing getting away with such an oversight!?
@@DanA-ji1vm Beats me. I guess they are too big to fail, and so are getting away with everything.
12:27 - memories of hanging onto the column for dear life exactly that whilst training in a Cessna 172
Mentour Pilot, I would like to thank you for addressing the question about terrain escape maneuver and for providing further explanation in this subject. You are doing an absolutely fantastic job with those videos. Keep it going and have a lovely, clear sky.
Thank you! I am really happy you liked it!
I have no particular interest in aviation, but your videos are always fascinating. Thank you!
For a non pilot, it is amazing what you go through to fly me to my daughter
The part I don't understand is why there is no disengage that stops all automatic trim inputs (ex. MCAS) but allows the pilot using the electric motor to trim manually. Car analogy: I touch the brake or shift gears, the cruise control disengages. I can then accelerate, brake and turn manually. The cruise control does not re-engage again. This system as it was built is like a car designed so cruise control can only be disengaged by turning off the engine, losing brake assist and power steering as well.
Great analogy! Spot ON! Only explanation that makes any sense to me is that Boeing ran out of money after paying their CEO & management & shareholders.
0:01 - omg Mento' is giving the yoke the HEIMLICH MANEUVER...!!!
Hahahahaha
No, just happy to have it aboard.
I'm glad you found a way to get this information out there without upsetting anyone. Bravo.
"Control collumn: Hold firmly."
"OOOOOOH I am."
Had me busting laughing.
Seeing you guys struggling to trim the aircraft brings chills really, only God knows what struggles the crews of Lion Air and Ethiopian Airlines went through
I am sure the folks at Boeing hate this video.
This video is not related to the MAX it shows a feature which is well publicized in manuals and should be fully understood by people flying the aircraft.
I totally understand that it has nothing to do with the max accidents but still it brings chills, knowing what the problem is and knowing how to fix it yet you can't because of aerodynamic pressures, very chilling
@@MentourPilot Dude, you were hugging the yoke, the force should have been huge...
Very good video, though!
Great Job! I'm a ATC at Boston Center for 28 Yrs now.
robert ATC Ah! Montreal ATC is always telling the aircrafts going south east to contact Boston Center, 134,9 ! 🙂
Very interesting. Would you consider doing a video of you and your copilot doing the roller coaster maneuver in the simulator?
Not at this point.
If you mean a roll, he has already done that.
kay g And disappear into the earth LOL!
copilot say oh no not me again , i have lost both my arm after this video
Would it make sense in a situation like this to triple-gong the purser so he can work on the captain's side handle of the trimwheel while the captain handles to control column?
What's the red button you mentioned? Can you do a tour of the behind the scenes parts of the flight simulator machine? I think that would be fascinating.
Q: What's the red button you mentioned? A: self destruct.
I think it's the record button on the camera.
i much believe it has to do with the motion of the simulator platform. an emergency stop switch to the platform..
@@altavaer oh yeah that makes sense.
I heard in a video somewhere, at some point, that it's bad luck to let the simulator crash. I presume the red button is a stop button. If you are certain the plane is going down, there is no point in letting it play out, and hence, bad luck.
Who needs a gym when u hav a 737 sim to practice runwaway stabilizer exercise
Ah, please show us the roller-coaster maneuver. It would be epic and since it's not been taught anymore, I'm sure everyone will find it very interesting. Also thanks for uploading this video and giving us a taste of what was in the deleted one which I couldn't watch. Thank you for everything you do. I'm not a pilot but I'm a scientist so I find plane fascinating in their complexity and ingenuity. So all the sims you show are really fascinating to me. Thanks again.
That was an Absolutely Fantastic Video!! Great explanation at the end of why you shouldn't turn to avoid terrain if you don't have visual! Great Stuff!!
EveryTypeOfVideo, do you like Every Type Of Video? :)
@@mauriciomarianocarneiro???
Just a joke cause of the nickname. 🤣😂
🌍🌎🌏 =D
EveryTypeOfVideo - Hi! Yes, you're right. Instrument training is bizarre. The cockpit's blacked out completely, so you can see absolutely nothing but your instruments. Learning to rely exclusively on them when you have (literally) zero visibility is enormously difficult and utterly non-intuitive. It feels totally unnatural.
Your senses are screaming at you that you're banking, or diving, or climbing, or even completely upside-down, but you have to ignore the urge to try to make sense of things. It's very hard to trust instruments alone when flying blind, but it's even harder to reject what your body's telling you to do. When up feels like down and left is 'obviously' right, you have no hope of avoiding disaster without the right training.
My flying is limited to a Cherokee 140 where trim is "small", simple, straightforward and obvious. This video put the "big plane" trim in a different perspective. I had no idea that trim could become such a struggle. I learned a LOT from this. Thank you!
Thanks for great videos. I would have enjoyed you getting out of the mis-trim as if it were real and also telling us about the altitude loss as it was going on.
Looks to me like the method of applying force to the trim wheels could be designed better, something that gives the pilots more leverage. Seems very clunky, and in an emergency situation could be downright dangerous.
Tack för förklaringen. Du är den enda jag hittat som beskriver problematiken. 👍🌟🌟🌟
That rollercoaster maneuver is similar to reeling in a really big fish..
We also had a recent tragic loss of life when a local pilot here descended into IMC and lost situational awareness with terrain on 3 sides, she added power to climb out, but also entered into a circular climb pattern where during the turn she struck one of the mountains and perished. Had the turn not been initiated, it was estimated she could have avoided the peak that she struck. Hindsight does have 20/20 vision, but a turn into the unknown when disorientated near terrain is certainly maximising your risk.
Another amazing video.
Thank you soooooooo much for the effort so we can understand how pilots work hard so we can enjoy our flight.
This has to be one of the best channels of TH-cam , if not THE best! Thank you!
Reminds me of the time I took off from Palm Springs in a Cessna 172. There's a mountain on runway heading, which I had been told to maintain, and I felt like departure had forgotten about me, as I got closer to it. I finally asked, "can I turn?", and they said, "Yes, assume own navigation". I turned!
accidents are always a stupid combination of unforseen events.
Two pilots is a great solution for safer flight, right?
I know this might sound crazy, but if you can’t trim because of aerodynamic forces, get some passengers to move temporarily.
In the scenario demonstrated, have 8 to 10 passengers in the front row go to the rear galley. That will move one ton from the front to the back.
Obviously this is dangerous for the passengers, but it’s better than losing control of the aircraft and crashing. The roller coaster makes sense, but if your altitude is too low, then you can’t do it. The only option left is to move the CG, to unload the stabilizer.
If you need to add nose down trim, just invite any pilots to visit the cockpit and I’ll be there in a jiffy. The passengers will just think it’s professional courtesy, but I’ll know you need help (because FAA regulations prohibit passengers in the cockpit) and you are deviating to save the flight.
I have myself been on a flight where passengers have been asked to move to help trim the plane.
at this stage, i reckon that Dog could fly a 737 :D
08:15 - Dog: We already did elevators !!
Dave Fox Is that a stick? Please, please, throw me the stick!
@@stuartmcconnachie Patxi would probably get scared if the stick shaker activated
Patxi is Snoopy's (Red Baron's) girlfriend, also a fighter pilot😁
@@keineahnung6124 Patxi is a boy!!!
@@iangill8984 oops!!,oh well it's 2019,let's not be judgement Al. Lol.
Mentour Pilot, I have been made aware
that the excessive force required to manually trim the horizontal
stabilizer on the B737 goes way back to the first airplanes and at
one time Boeing had a flight manual procedure on how crews were to
deal with it. So why didn't the FAA demand that Boeing redesign the
system to correct the problem? Was it because up until the Max8
debacle it was simply a non issue because the main electric trim
system never failed to operate and never ran away and the autopilot
servo motor was almost as good? In 32 years working on 737's I only
saw one autopilot servo motor that failed to operate and that was
because a human removed it's electrical connector before flight and
failed to reinstall it. Therefore the crew simply didn't use the
manual trim because it was not need until the Max8 debacle which
forced the crew into trying to use a system that Boeing and the FAA
knew would not work under the conditions that the crew was faced
with. In my opinion a chain failures led up to this situation and
they are as follows: #1 AOA sensor provides false data to poorly
programmed MCAS system #2 MCAS causes autopilot stab trim to run
toward full nose down trim. #3 Flight crew treats this as a runaway
trim situation and follows the flight manual. #4 flight manual says
turn both stab trim cutout switches off and left
off. #5 Boeing has changed the wiring on Max8 airplanes so that
turning off either switch turns off both motors and also tuning on
either switch back on turns on both the defective autopilot servo
motor and the good main trim motor. #6 Crew is forced to turn the cut
off switches off again and trim the stabilizer manually, which they
cannot accomplish and we all know the sad ending.
Lmfaao the toilet-backpressure analogy 😅😂
Thank you Mentour for the detailed illustration of the trim system, I was wondering how the mechanical system worked.
Mentour, GREAT VID! I can't help but to wonder what happens to a pilot after a missjudgement like in your "terrain, terrain, pull up" video? Does the pilot file a report and if so what then? Thanks.
Yes, a report is filed and the CVR is retained for a subsequent investigation. What happens to the pilots depends on the investigation.,
I turned off notifications from your app a few weeks ago. Back then you got a notification of somthing you said and when clicking the notification I was just sent to your chat channel in the app. Don't underestimate the work it takes tom make a good app. It seems you have so far.
Why does a Herkules have 4 AOA sensors and a passenger jet only use one of the 2 AOA sensors? Seems that aviation have been too focused on costs!?
You went ahead with the “Red” and “Green” (port and starboard) pillows! Yay
EXCELLENT video! Finally a well explained video telling what might have happened to that 737 Max.
Exactly what came to mind and as in the early report referencing speed and angle, it may explain the situation they faced it's chilling.
I can see that it is almost impossible to trim any 737 manually further nose-down if the mis-trim is already down. But the BAD situation is that it is IMPOSSIBLE to trim it manually in the REQUIRED direction to save the aircraft, to trim it nose-up. The cranking of ONE pilot can NOT overcome the aerodynamic force that is against the manual trim-up effort. Two pilots would be needed to overcome the limitations of the mechanical (emergency) system. But one of the pilots has to pull the yoke back with all his force and has no free hand to assist the manual trim effort at his side with the second cranking handle. The FAA should look into this too. Why was the 737 NG certified in this DEFICIENT way? The problem was already existing before the 737MAX. Suggestion: The TRIM CUTOUT switches should be changeover switches that disconnect the primary electric trim system that includes the autopilot trim, trim switches at the pilot's control wheel and the electric motor near the jackscrew. When doing the switchover there should be an alternate electric trim system with an alternate (additional) set of trim stitches at the control wheels and a DC-motor in the pedestal which (via a clutch) is able to drive the trim-wheel in the pedestal. The electric DC motor has to have enough torque to drive the (former exclusively manual) system and should be connected to the Emergency DC bus. Second suggestion: FAA should mandate this modification to ALL 737 within six months.
Cockpit warning: Dog Bored! Play! Play! Play!...Dog Bored! Play! Play! Play!
I've done some video editing before and tried to make things look consistent from one cut to another especially where you had to do something similar to what you did, there's always something that changes, the dog teleporting in is hilarious!
Hey Mentour, you should do a video about the Stratolaunch plane, largest in the world :)
These videos are the best. I'd imagine it's pretty fun practicing for these with your airline.
these being exposed shows what pilots have to put up with and keep calme with a straight face.
Pilots are seriously special people.
Great action packed video Mentour i enjoyed it, wishing you good health and back to flying soon my friend. Have a good weekend.
I love your Channel and all the information and lessons that you teach me. But I have to say that you're dog is so cute. I always watch it in the background. He/she really loves you!!
Amazing videos. Hope you get back flying soon
He has kidney stones. Unable to fly at present.
@CSRT4 Ever he is on medical leave and has been for a while
Loved the "Just teleported in" caption around 17:05.
Another brilliantly informative video, can't wait for the next one!
Careful, we don't want to snap off that trim handle!
And it's no coincidence that those wheels look like exercise weights...
Between the advice of "not try this at home" and Patxi's teleportation super power I am speechless..!! Hahah great video as allways, thankyou Peter for this kind of demonstrations, showing the case of something going beyond all limits.
we did something similar with a c-172 sim. the c-172 trim system somehow failed and its stuck full forward. we still did our lesson of 4hrs instrument training and it was really a workout in the gym. we were literally hugging the yoke while practicing instrument flying. it was one hell of a lesson :)
Very interesting. Stressing the incredibly wide speed range of a big passenger jet is vital information for a lot of people who perhaps aren't familiar with aviation. A small plane like a Piper Cub or a Cessna 172 will have a takeoff and landing speed not much different from its cruising speed. So, say, from 75mph up to 140mph (NOT accurate figures, just an example!).
A big jet might cruise at over 500mph, but take off and land at only 130 or so. That's a huge difference. Imagine driving a car without power steering at its top speed of 120mph. Then try it at 240mph. Then 360mph. Then 480mph. The steering forces would be incredible, and very difficult to control.
Air is amazingly thick, dense, 'heavy' stuff at high speeds. It's more like pushing against water, so it's easy to imagine how hard it must be to overcome a big jet's colossal aerodynamic loads without hydraulic assistance or any kind of 'power steering'.
We did that 120MPH in my Dad"s Sprint Car. My XJ12s do 150MPH. Your point is?
Unpowered steering becomes easier the higher the speed.
Not sure what your point is. In the video the elevator control still has hydraulic power assist, which was working well. Power assist always has a taper-off function where there is decreasing assist towards the limit of the movement as well as a reduction of assist with increasing speed. This is to prevent slamming the controls against their mechanical stops with destructive force and to avoid abrupt maneuvering loads that could exceed the strength of the structure or could cause violent maneuvers that jeopardize the mission, e.g. cause a rollover in a car or skidding and loss of traction.
The whole point of trimming is to position the stabilizer so it is doing all the work to hold the airplane in the desired pitch attitude with zero force on the elevator, i.e. for a 737 and other large airplanes, the elevator is in its neutral position, lined up with the stabilizer's chord line, with deflection from that position available to cause quick changes in pitch attitude if necessary.
Thanks for showing how the second 737 MAX crashed. The MCAS was working against the pilots with constantly 2.3 units AND on the trim and 100 pound force on the column was induced by a 500kts nose-dive into the ground without any chance to pull up again.
I thought "why didn`t they just trim the plane per hand after trim cutout?", and this video explains perfectly that this is impossible. Except for bodybuilders whe urgently need an excessive five minute workout during a steep nosedive.......
The very fact that, at really critical moments, really huge physical vigour is required (and even that my not be enough), shows what a joke female "pilots" are. Here, too, women are a recipe for disaster!
‘Dwayne Johnson to the flight deck’.
‘Do not do this at home’ - surely you mean ONLY do this at home 😅.
Juck Norris as copilot would be able to trim the stabilyzer manually in highspeed misstrim situation with his left ear.
Very interesting, I see the connection here that when there is a trim overun situation the pilots mind in a time of extreme stress especially, defaults to throttles to the wall and pull up as trained for terrain emergencies, which would make the trim over-run manual adjustments almost impossible at high airspeed and elevator, quite concerning
I do wonder why there's no possibility to disengage all systems that automatically trim the aircraft without also disengaging the manual trim using the motor. I can see how being able to physically trim the aircraft is valuable if the motor breaks or can't be controlled anymore but there should be a step in between where only the automatic stabilizer systems are disengaged in my very humble opinion. Can anyone shed any light on this design decision?
@Penny Lane
LOGICAL.
In the end one of the big issues today is pilots need to remember how to
_"Just FLY the plane"_
Spot ON! You nailed it! There should be a new step in between where ALL auto control systems are disengaged but the jackscrew electric motor remains in play controlled by the cockpit up & down trim pushbuttons.
I was wanting to go to toilet after a big meal and there was a Long queue once, Unfortunately No matter how Hard tried i couldnt apply enough back pressure. I Had to Dump Fuel There and Then !!
That reminds me of a story in my initial pilot training when I was flying a small Cessna cross country (by myself). On those long flights and not having a toilet, I had to use an empty bottle to dump my fluid into. When I lifted the now filled bottle and reached behind to put it back into the cargo area, I had to re-trim the aircraft afterwards. I was surprised that it made a small but noticeable difference.
737NG - genuine fly-by-wire :-)
Lmaoo
i believe the newer fly by wire joystick is the oposite of the older fly by cable with a yoke control.
Airbus did away with the weight of some mechanicals and replaced them by mostly reliable software logic
Hahahaha.....cable is also a wire.
I am really surprised they haven't redesigned that manual trim wheel lever. The could make the design to were handle first is a little wider and easier to grip. You can actually lock out that lover and have it to where it can pop up extending the actual lever so the pilot or co-pilot can actually provide more leverage and it will give you more force making easier to trim.
I keep commenting this but your videos are fantastic and well explained 👍👍👍👍
Wow great Explanation... Mentor.. Thanks a lot for your effort. One thing understand from here is you need to know all the physics and the mechanics of the flight control...
Back in the days when I was a flight simulator mechanic, I would have been angry at you.
Damn! Flight simulator mechanic....that's a specialty...! 😀
@@henryrollins9177 that's actually what my papa (maternal grandfather) used to do lol
why?
Your dogs make me laugh every time! The brown one makes me think of a Steif stuffed animal. I believe that they just enjoy spending time with you on the couch during your talks. So relaxed!
Great video!
"The red button" - I wish they have it in MAX...
When I was in college there was a prank people in the dorms would play on each other where they'd have some people push super hard against a door while one person wedged as many coins as possible into the space between the door and the frame. This would keep lots of pressure against the door, which was applied to the bolt. The bolt then had so much friction that the person inside could not physically turn the doorknob and so they were locked into their own room.
Well done, Copilot! You showed a lot of man- muscle- power! xD
7:07: Your cute and lovely little piece of paws, fur, and tail. 7:26: That cute little head moving.
You'll break the simulator!
I was worried the machine or copilot was about to break.
Samir
This was excellent. The addindum for the pull up exercise makes total sense. Thank you.
If my memory is OK to move the stab for 1 degree we need 15 manual rotation of the trim wheel. For 4 degrees - 60 rotation and this will take about 1 minute.
Toriy ... Well, in the case of Ethiopia they hit Stab Trim CUTOUT about three minutes into the six minutes, but hey, why not then rewrite 50-year-old tried & true runaway procedure in mid-air instead, right? (21:33) ... and return the Stab Trim CUTOUT to Normal?
_
1 min - this is in ideal situation, if there are no high forces on the stub. If there are forces, as we can see from the video above (some rotations took more than 5 sec from the FO), manual trimming does not help or takes more than 1 min. If you are, let's say, 5000 feet AGL and going down with vertical 2000-4500 feet per minute... I am not sure that any vertical S maneuver may help for 100%. Ideally they have to trim forces first and then use CUT OUT... Ethiopian pilots switched the system back when they realized that manual trim is no help (if I understand properly) Yes, I think the time really has come to rewrite the procedure for the 737 family. I believe, pilots worldwide know about the situation, but looks like they really need a help here from the manufacturer. But again... the authority of the Yoke must be enough even with the is stub fully up/down, isn't it?
Toriy Shaov No. A fully deflected stabilizer will quickly overwhelmed the elevator. So pulling on the yoke is useless.
An addition to the present manual trim wheel : a small central toothed gear that slides out of the trim wheel's " wheel", on the co-pilot's side; and another handle that can swing a 'worm gear' onto the center toothed addition. Then a small handle on the worm gear wheel turns fast, exerting a very high torque on the trim wheel. Then, the worm gear handle swings away, and the splined center gear pops back flush.
Thx that you explained this technique - roller-coaster or just yoyo effect that I mentioned in the previous video 😊
Not sure if you even read TH-cam comments anymore, but I just noticed your nav light pillows on your couch. I think that's neat for a pilot to have. Or should I say, super cool!
Thank you!! I thought I needed something aviation inspired in my sofa!
I'm really mind-blown. I don't understand why in a big plane like a 737, a pilot should ever be required to use a big amount of his physical strength on the controls in order to move the elevators, or any other flight control surfaces for that matter.
An electrical engine that weights about 4kg is able to match and exceed any amount of force that a person can exert with his arms. Surely we should have the technology to do that on such a big plane!
Having to struggle with any demanding physical task seems very distracting, and an impairment for pilots that could already find themselves in a high-adrenaline emergency situation.
And considering that male pilots already seem to struggle, female pilots could have even more of a hard time coping with that.
I can understand that the need to apply more pressure on the control stick can provide some useful feedback information to the pilot, but surely it should be possible to employ some servo-assisting technologies similar to the ones employed in modern car steering wheels, so that the pilot could still feel some pressure on the control, yet they would never have to struggle to push or pull the controls.
It’s an old bird. And we are talking some serious non-normals here.
This failure is to account for when the electric motors have failed.
He's demonstrating extreme control forces created by intentionally extreme mis trimming of the horizontal stabilizer. Pilots would not do this intentionally on a real flight. Perhaps test pilots in certification flight tests.
Andrea Chiavazza absolutely correct. I am demonstrating a phenomenon, not a normal occurrence.
I flew a Rollason Condor at Shoreham..used to trim by rotating a large wheel by flaps lever and hands off to see if plane dived or climbed, easy to use and stabilised within seconds. doing final approach used to also operate carburretor heater
Thank you. That was fascinating. One thing I found myself wondering: in this situation, would you consider calling someone else into the cockpit to help the co-pilot wind the captain's trim handle, since you weren't in a position to do that yourself?
No, there wouldn’t be time or a possibility to do that. In any case it would be almost impossible to explain what needs to be done and for that person to access
@@MentourPilot unless he or she is a Mentour Pilot’s subscriber
With the miss trim demonstration , I believe he was referring to the fatal Ethiopian flight without actually mentioning it. With the speed the aircraft was going, full thrust after takeoff, and the stabilizer severely out of trim due to erroneous activation of MCAS, it was virtually impossible to manually trim the aircraft nose up using the manual trim wheels. The roller coaster maneuver was out of question because the elevators were already overwhelmed by the out of trim stabilizers. Also, they were too close to the ground.
And even if they were able to move the manual trim wheels, it would have been too late, as it would have taken too long before they could manually trim the aircraft nose up again. And they would have still crashed. So sad.
Mentour Pilot, or anyone who knows, can you explain the EXACT difference in function of the 2 Stab Trim Cutout switches on the various 737 models? A thread / comment on a machinist forum claims the 737NG has the switches labeled as "Stab Trim Cutout" & "Auto Pilot Cutout" meaning that the Stab Trim Cutout switch deactivates ALL power to electric trim motor but the Auto Pilot Cutout disables ONLY automated trim commands leaving the pilots thumb trim switches functional. So the function of the 2 switches is DIFFERENT. As I understand it--- in the 737 MAX what used to be the "Auto Pilot Cutout" switch is simply labeled as a "Backup" for the "stab trim cutout", both switches have the SAME function and are always operated together. I looked at google images of 737 stab trim cutout switches and indeed I see switches labeled both ways but the pics are not necessarily noted as to which plane version they belong to. In all the discussions about those cutout switches and runaway trim I've not heard any case where one switch would be operated without the other, they are ALWAYS moved together.
Many comments on the recent 737 MAX crashes have suggested there needs to be a way to shut off the automated trim commands but leave the manual electric trim functional. Some even suggesting there needs to be a BIG RED BUTTON to deactivate uncommanded trim inputs. Can it be that earlier 737 versions indeed have this ability? But the MAX does not?
NOTE: couch pilot
the stab trim cutout probably cuts out the switches on the yokes and the autopilot one the autopilot. they're probably always moved together because the pilots are not isolating the fault yet. The "big red button" is probably the AP disconnect switch on the yoke switch is used to quickly cut power to the trim motor. (easer to push) I'm not sure about the differences between earlier 747s and the 747 MAX (again, couch pilot) but I'm pretty sure that's it.
Simply one of the best aviation videos I have seen. LOVE the PMDG 737NGX. Will try it at home...
11:58
DO NO TRY THIS AT HOME!
Me: Cool I won't.
Great video, both the main portion and the terrain escape addendum.
Would love to see the “roller coaster” demonstrated in the simulator!
Maybe Boeing should add a two speed wheel control (like boat's winches) in case of high speed manual trim operation)
Or require mandatory workout for first officer ;)
there is a trim wheel on each side.
Seems the nature of manual trim wheels make them useful in only a few situations (slow operation, lower air speed, surface load).
Adding a few intermediate gears could make the trim handles EFFORTLESS, right ??
@@glasser2819 With the right gearing, a hex "nut" on the wheel axle, and a handful of charged up Harbor Freight cordless drills (better buy their "premium" brand to pass FAA muster) with matching sockets on them in the cockpit, that should work fine.
It's already slower than automatic trim, increasing the gear reduction would make it eve n slower
re: "require mandatory workout for first officer" 12:37 - DAMMIT LORENZO, PUT YOUR BACK INTO IT...!!!
Seems like a second set of electric trim motors not linked to the automation would of been better than a hand crank. Like they say in the GTA 5 avenger mission "who still cranks?"
You've taught us a lot of stuff so far! Thank you *VERY* much and keep it up!!
What minimum altitude is required for the rollercoaster/trim manoeuvre?
This would be an emergency procedure with many variables, the only mandatory item being don't hit the ground.
@Thomas Headley ... Why would the overheads be opened? Doesn't make sense for the maneuver shown. It's not a rapid, violent drop like would happen in strong turbulence.
Excellent video mate thank you so much for taking the time to explain so clearly and also love the simulator videos
Great video as always. Thank you!
Thank YOU for being awesome and watching.
Okay. Nice video. Now explain how the 737 MAX and the MCAS minimize, maximize, mitigate or aggravate the stabilizer control crisis you described. I just love it when the flight control systems and the pilot get into it over who is really the PIC.
Should the electrical motor fail, say 'locking it up'....will manual trim be able to bypass the stuck motor ?
the trim wheels being hard and slow, the manual procedure seems applicable in only few cases for small trim adjustements.
As demonstrated in simulator,
others "run away" cases when plane level is too far out of trim... very limited chance of success. 😂
An example of when the terrain escape maneuver would have saved a whole plane full of people: Dan Air flight 1008. The pilot chose to go into an extreme bank to try and turn around and get out of the high terrain, rather than just leveling the wings and pulling up while applying full power. The plane impacted terrain at a steep bank angle and nobody survived.
12:30-when I put the lid of the salad spinner on crooked.
Even though it was a sim, my hands were sweating watching this... Wow...
The MCAS glitch caused it to take over the horizontal stab and put the plane into a dive. The pilots corrected by switching off the toggle switches to disable the automatic horiz stab control. Question I still have: Why did the pilots switch the toggles back on? Was it because, with the toggle switches off, the hand crank is also disabled, and so they had no choice but to switch the toggles back on to have a chance of recovering from the dive? Even without the horiz trim way out, why would it be so physically strenuous to manual trim using the hand cranks? There's no motor assist for the hand cranks? It's just old fashioned mechanical linkage?
The mechanical backup system is connected to the trim actuators by cables and drums. MCAS had driven the system to the stops using the electric motors and no amount of manual force could overcome the aerodynamic forces at the speed, altitude and elevator positions existing.
@@paulavery366 Part of the problem on the Ethiopian airplane is that the crew never did anything to control their speed, when the aircraft pitched down. They basically went into the dirt at takeoff power. They also didn't cut out the trim system until the aircraft was badly mistrimmed. As a result, the airplane was flying at or beyond its maximum operating speed, and the pilots could not overcome the aerodynamic forces with the manual trim wheels. They likely turned the trim system back on because they believed that only the motors could budge the stabilizer.....which was true, but they would have needed to do things perfectly to recover.
They were likely almost beyond the point of no return. Their only real hope of recovery would have been to get the power to idle, pop the speed brakes, turn the trim system back on and IMMEDIATELY dial in some nose-up trim, followed IMMEDIATELY by again turning off the Cut-Out Switches. If they could get the airplane slowed down and get the stabilizer far enough off the full nose-down position, they might have had a chance to manually trim the airplane......or perhaps go another cycle of turning the trim back on, dialing in a burst of nose-up trim, then turning it back off again.
I always have to keep going backwards to hear what he said because I cant keep concentration when I see those cute puppies!!!!! ❤️⭐️
Would an Airbus in direct law in the same aerodynamic stress be as difficult to trim - clarify meaning elevator force would exceed ability to ovecome stab trim?
Roller coaster maneuver kind of like reeling in a big fish. Dipping the rod to reduce line tension & take advantage of increased slack while reeling in before pulling back up again and repeating the cycle until the result is achieved.
Do an introduction to your four-legged friend in a future video!!!
It is very impressive showing your pilot`s skills and what could happen behind the scenes - but I am thinking about using a train next time.
Hello Pilot and F/O 😊😊