The strength of that pylon holding the engine is incredible. You'd think with all that force, that it would snap off the wing. Great video! Cute dog. 😀
@ electron. it's not just the pylon... the engine is mounted onto the pylon / wing via explosive bolts...!! the bolts are used to secure ie hang the engine to the pylon / wing BUT at same time are designed to shear off and "release" ie let go of engine in case of accident, so that the engine would not rip the wing apart..!!
I understand that this is mostly directed to new pilots who are just beginning to learn their craft,but it is immensely fascinating to those of us who aren’t and probably will never be pilots.
@Honkler In that case Dutch and Swedish accents in English sound similar to you. Most Swedes who speak English with a bit of an accent sound like that.
I was in a DC8 many years ago. The pilot wanted to quickly lose altitude to avoid a thunderstorm and reversed thrust in flight to quickly land. I was amazed while none of the other passengers seemed to understand what was happening. Never forgot it.
@@charliebrown6161 A DC-8 most certainly does have spoilers (aka speed brakes). Erroneous deployment of the spoilers shortly before landing in Toronto is what crashed Air Canada flight 621, a DC-8, in July 1970, killing everyone on board.
@@HartmutWSager There are quite a few variants of DC-8 with radically different features. Some criticism of that denzel film with the extinguisher for example not cutting the engines, genuinely was possible on that earlier style of DC-8. In this case only the first few out of the factory had airbrakes, as it was removed before full deployment.
@@carbon1255 Indeed, there are quite a few variants of DC-8 with different features, just like there are in most other plane series too, but are we even talking about the same item here? You have again referred to "airbrakes", which I took as a mislabelling of "speedbrakes", which itself is a mislabelling of spoilers. If you are referring to spoilers, practically every large jet aircraft of the last 70 years has them (to diminish lift right after touchdown). Otherwise, what are you referring to with "airbrakes"? Obviously not the reverse thrust mechanism (though the term "airbrakes" might be apt there), since you are separately referring to reverse thrust. Please clarify. Love your logo! But, you didn't want to "be dated" with Carbon-14? No spare neutrons handy?
The Lauda air plane, that crashed was called " Mozart". I flew with her the same route from Vienna to Sydney one year before the accident happened. She was brandnew. I never felt so safe. Couldn't believe it when it happened. I sat in this beauty. All the flight attendants were beautiful modells from the catwalk. So sad! This crash destroyed the upcoming " Lauda Air".
Can only imagine how amazing that was. FAs now on US airlines are generally the opposite of runway models. Nikki Lauda clearly knew how to run a class operation
I just have to say, I found this channel only because of my interest in supersonic air travel and interest in the Concorde and thanks to a couple of your high quality videos on the subject, I continued watching more and more of your videos any time I have a question or curiosity regarding air travel. Your content is phenomenal! I'm borderline addicted to your videos, I can't stop watching, they all seem so interesting and captivating! Also, I'm a huge automotive enthusiast and it's interesting to see how much translates from the auto world to the aircraft world. I have a pretty good understanding of a lot of things you talk about, such as when you talked about brakes and braking in this video.
I was a passenger on a DC8 where the thrust reversers broke off on one engine immediately upon landing in Calgary many moons ago. The aircraft crabbed sideways and hopped up and down in the air. Rather scary. I was on a flight from Vancouver to Montreal and after 8 hours of waiting while they were repairing, they announced they were transferring us to another aircraft and we all cheered.
This actually happened a while ago on a 767 in mid-flight and during cruising, it caused a massive bad chain of events. The aircraft reached extreme G-forces and then broke up and crash into a mountain range, unfortunately, killing all on board.
First time I watch one of your videos, and was impressed you knew the 10ft or below radar alt thrust rev deployment was possible. I know guys licenced on type who don't believe me when I tell them that. After the Lauda incident, there were two AD's I distinctly remember directly related to that crash, that came out on the B732's I was working on at that time. One was a mechanical lock on it's JT8 buckets and the other had to do with passenger seats. I once watched a BA B744 have 2 engines go into uncommanded thrust rev right after rotation. The mechanical locks that were incorporated on the RB211 after the Lauda crash meant the reversors only extended about 2 inches before mechanically locking. Of course the power automatically reduces in said engines, but she was able to climb out with full pax and around 118 tons of fuel. I say around 118 tons, because thats what we used to fuel our B744 for the same route.
As always, your explanations are on point and very well for me as a "normal" curious passenger to understand. Thanks for taking all the time and patience! :)
Love your show! Very well explained..... my curiosity has been answered.... I’ve always been fascinated by the subsequent investigations of air-crashes and how the industry seems very committed to understanding and improving the engineering of airliners, pilots and processes. Nice to know that you’re also keen about understanding. Keep going!
On the DC-8 you don't have in flight spoilers / speed brakes to slow down the plane on descend. The plane only has ground spoilers that activate when you have weight on wheels. In flight you can engage the reverse thrust on the inner (n 2 and 3) engines. It's a interesting plane to fly compared to more modern designs.
True - I got my flight engineer rating on the DC-8 and you could use idle reverse inflight on the #2 and #3 engines. Some crews would not do it, and Douglas apparently was concerned enough about a stuck reverser inflight that they put an "emergency stow" switch on the captain's overhead panel.
When the propellors change pitch angle to reverse thrust there must be a huge amount of pressure at the hub bearing for a few seconds. Been in a turbo prop and you can feel like you are being wrenched out of your seat for a moment until the aircraft slows down. Love the moving cuddly toy beside you, very realistic, looks like a real dog trying to get affection from his master 😀😀
Farlig66 ya he treats the doggie like a teddy bear an inanimated object. Should give some video time to the dog by petting the dog giving it some attention .
Thank you for mentioning that the DC-8 can deploy thrust reversers and descend rapidly. I remember reading about this in an aviation magazine in the mid to late 1960's. Now, my pilot friends can stop thinking that I made it up. Happy Landings, Mack
Correct me if i'm wrong, applying reverse thrust allows you to reduce brake's input and thus limit heat's rise. But if you apply maximum reverse thrust and maximum brake, aren't you supposed to stop faster?
I agree with Slyze33, applying thrust reversers on full and full brakes WILL DEFINITELY shorten the landing distance. Mentour clearly said there is no difference.. This does not compute!! Maybe we are missing something here.
@@ashwinmohan4503 the brake settings specify a rate of deceleration, so from a pilots point of view the statement is correct. The pilot won't actually decide how hard the brakes are worked he only decides how fast he wants to stop.
@@stefan514 The "guy in the video" is an instructor pilot for an airline. I agree that it wasn't phrased as well as it could or should have been, but the context is "what do we do in line operations?". This isn't a video or a channel for people who are interested in 130-0 deceleration runs with $100M aircraft for shits and giggles. The answer is, "we use reverse thrust to reduce stress on the wheel brakes" which is EXACTLY what he said in the video.
Don’t know if it’s still done this way, but when I was flying the Jurassic and classic B-737’s runway RTO and landing figures were based on brakes only so T/R added a safety measure. Not to imply they don’t reduce landing distances because they do quite well. We used to power out of some gates on rare occasions when a tug was not available. As for deploying the T/R before touchdown, besides being a bad idea a pilot considering it should fly/land that particular airplane a few times beforehand to confirm the T/R deploy simultaneously. If they’re not synchronized which happens you’ll hit the ground on the side that deploys first. Maybe to the point of damaging the A/C.
I remember the Lauda Air incident well. As far as I remember the pilots had the time to check the handbook, when the indicator for the thrust reverser came on - and it stated that there is no action necessary. So they probably might have had time to shut down the engine before losing complete control - if they would have known that this is the correct action. I think Boeing until then believed, that such an incident would not be possible and that the thrust reverser indicator could only be a malfunction of the panel. Tragic mistake. Niki Laude proved then in many simulator tests, that the pilots had no chance to regain control and the fault was clearly with Boeing. Thanks again for the great video! And your dog is just lovely!
The pilots reduced power to idle and even cutoff the fuel, but not fast enough. In the sim, they showed that the crew would only have 3-4 seconds to shutdown the engine before a catastrophic failure. They missed that window by only a couple seconds. Extremely tragic. Niki Lauda is a hero, forcing Boeing to fix this problem once and for all.
I always love it when the thrust reverse is used, especially when it's wet out. Sounds and feels amazing. I'd be the guy craning his neck to look at the engine haha
Lauda air 004 is worth a mention, among others. Thrust reversers have interlocks on them now because there have been a few accidents due to inadvertent deployment.
What I gathered is that they use reverse thrust to (partly) replace braking instead of using using both at max. So they don't try to reduce stopping distance, maybe because that would just increase the distance they have to taxi, maybe because that would be uncomfortable. If they would rely on a combination of reverse thrust and braking to land on a short runway, you've also got little margin for error. One sudden rain and you're no longer able to land.
@@DutchBlackMantha That is okay, so it is not calculated like that, but the question is not why they do not use it to further reduce stopping distance, but why is that has zero impact on it. This part is also not clear for me. If you can stop the plane with brakes on the same distance as you can stop it with reverse trust /okay, not exactly/, then adding the two up together should reduce the stopping distance. So once again, I understand that they do not do it, and I understand why they do not do it, so my question is more related to physics than let's say logic.
It doesn’t make sense, because he’s wrong about that part. He is confusing planning and safety factors with physics. Of course they don’t want to plan that reverse thrusting will reduce braking distance, because if it fails, they may not be able to stop safely. But any time reverse thrust thing is being used, it absolutely does reduce braking distance. That is just undeniable physics.
@@bobbyjbobbyj Yeah he missed that part of the explanation. If its done in dry conditions why would the breaks not get as hot? Because the reverse thrust took some of the kinetic energy the brakes otherwise had to suck up all by themselves. And if you would apply max brakes and max reverse thrust you wouild stop sooner but with hotter brakes.
@@albinfiskare I understood that part. I was also confused, he explained it like even if you had max breaks and full reverse, you would take up the same stop distance as just full breaks. That part didn't make sense.
The DC-9 series 30 actually always deployed their thrust reversers in flight as a matter of routine. Watch videos of the “9’s” landing. Take note when the reversers are deployed. You should see they are deployed after the mains are on the ground but before the nose is on the ground. We would pop the reversers without adding power on touch down and let the drag of the reversers gently lower the nose to the ground. Once the nose was on the ground, we then would add power to provide negative thrust. The DC-9 is not officially on the ground until the nose is down. That is because it did not have a WOW switch on the mains as with most other large commercial aircraft. It has a “Ground Shift Mechanism” on the nose gear. So as far as the aircraft knew, we were deploying the reversers while the aircraft and all the systems were still in the air. The longer series 80 DC-9’s didn’t do this because the engine exhaust were so close to the ground at landing attitude, the reversers would actually strike the ground if deployed and break off. This fact was learned the hard way by Hawaiian Airlines.
"As a matter of routine"? Hardly. The aircraft operating manual prohibited it, and a captain would be disciplined by the company, if detected or reported. Also, he would be in serious trouble if he had to cancel the reverse for a go around, in which case a full 8 seconds would be required for the engine to transition from reverse idle to take off thrust. I also have a type rating (And 8,000 hours) in the BAC 1-11, with the Rolls-Royce Spey engine, which was approved for use of reverse thrust in flight, as the idle to full spool-up time was only 2.8 seconds, as quick as propeller thrust. It was also approved for the use of idle power on approach, because of that advantage. This resulted in very quiet landings, with no reverse and long roll-outs, traffic permitting, and the terminal was at the far end of the runway. (10L at PIT, for example)
I enjoyed this video very much (and your dog is awesome). This topic has been on my mind for some time: About a decade ago I caught a ride on my employer's Citation III. It was a long flight, and I was sitting in the back row by myself. Out of curiosity I started opening cabinets in the head-compartment and found the flight manuals. I'm an aviation fan and an engineer so I was drawn to the manual labeled "Emergency Procedures." I opened to a random page and the first thing I saw was "Inadvertent In-Flight Deployment of Thrust Reverser." The thought that something like that could happen had never entered my mind. My brain did a quick calculation of the moment that would be created if one side deployed at speed while the other did not. All I could picture was our pretty plane turning into a Frisbee. I'm not a nervous flyer, but this was enough to make me put the manuals back where they belonged and return my attention to the novel I had been reading.
When I was in my early 20s, I am now in my mid 50s, I flew from Orange County, CA. to Sacramento Metro on an Embraer Brasilia. When the pilot was entering the landing pattern he did, in fact, bring the prop pitch in to beta. Whether by mistake, or because he needed to slow the aircraft quickly. I was sitting just behind the port wing, and had a clear view of the port engine. I could hear the change in prop sound, I could see the change in the prop silhouette, the engine did begin to shudder significantly, and visibly, and I could feel very significant deceleration over many seconds. I have since asked a few airline pilots about this, and have been told that this would NEVER happen, but I know what I experienced. I think that those pilots were just talking the party line. At the time this event occurred, I did already have some small aircraft flight experience. I have not before, or since, experienced that sort of deceleration over such a long period of time. I can say that it was quite an effective way to slow the aircraft.
My dogs show up to band practice and lay out in the middle of the floor... Labs. Gun dogs. Not afraid of noise AT ALL. I have one that follows me around when I vacuum.
Let me sum this us. "We use thrust reverse because there is no reason not to" Basic physics in play for frictions both for safety and for efficiency of the aircraft. Great video.
But what I really want to know is when the runway is dry and you enable reverse thrust and there is loads of air driving forward why doesn’t that slow down the plane but when it’s wet it does. I understand how the brakes work and that they need cooling but when it’s wet why do the reverse thrusters slow down the plane but not when it’s dry 🤷♂️ Please like so this can be answered Thanks
He's overgeneralizing or not explaining fully. When it's dry the thrust reversers will obviously still provide a force which will slow the plane more, it just isn't nearly as big of an influence when it's dry versus wet. Just like when it's wet you'll still get braking force even though it's less but it's not zero.
David Landon ok thanks so much for your help final question why is there a difference in the amount of thrust when it’s dry compared to wet is it due to the fact they just add more power?
@@tomwhyte Air conditions affect the power of engines in a few ways. Colder is more power because denser air, some water can actually add power because it expands into steam but that's a fairly small increase. As I understand it wet conditions shouldn't impact power significantly.
@@dlandon2000 Effects of humidity on turbine engine performance have been extensively tested. Moisture content itself has no direct effect on combustion, however atmospheric conditions associated with humidity have a negative effect on performance due to decrease in air density associated with rise in humidity. Condensed moisture is a bit different in the fact that H2O as a liquid is non-compressible, and therefore has even more of a negative impact on turbine engine performance due to volume it occupies in the compressor stage that could be compressed air. This reduction in total air(oxygen) has the same negative effects as lower air density on overall thrust/performance that is not offset by said moisture changing back to steam.
Tom, it is explained, watch again ;-) "Reverse thrust is not used to reduce the distance but to help reduce heat on brakes" means that they do not try to get the shortest distance and rather use the same distance, applying less brakes, thus generating less heat (you know, the time needed for the discs to cool down versus the short time available between rotations...). On the other hand, on wet runway, the brake on wheels is poor since the anti-skid releases the brake to avoid loss of control and going out of runway. You can compare that to the ABS on a car (with the difference of the amount of energy -mass/speed- involved). So you need an alternative way to kill speed AND keep on the runway; the reversers slow you down and the wheels keep the trajectory. Remember the planes wheels are quite slick and really subject to aquaplaning, then the job of braking is transfered to reversers so less adherence is required for the wheels. In wet conditions, heat is a lesser issue than on hot dry days. So, wet or dry runway, reversers actually slow down the plane, but for different purposes than shortening the distance. Hope this helps.
Actually, the Space Shuttle trainer aircraft, a highly modified Gulfstream 2, had the capability of reverse thrust in flight. Not sure if it came that way or if they modified for that. But, they took astronauts up to 38,000 feet and threw the engines into reverse to simulate the rate of descent of the orbiter. Normal glideslope for an airliner is about 3%, for the orbiter, it was about 22%. That's headed downhill quite fast.
A trust reverser would be if you got on the intercom before flight and said “Hello, this is uuhhhh your captain speaking, and uuuuuhhh this is my first day as a captain uuuuuhhh have a nice flight”.
I'd be able to relax under those conditions. If he said it was his first day as first officer, I'm boarding the next flight. I don't know of any crashes where it was the first officer's first day, and I don't want to learn of one through first hand experience 😂
I love your videos and find them fascinating, and hanging on every word you are saying but I am totally watching your dogs the entire time. They are freaking adorable and stealing the scene from you.
Once i saw the engine “open” just before landing. I was really scared. Then, I looked over thrust reverse and finally figured out what I saw. It occurred about 1-2 min before landing, and I assume the put it because of excessive landing speed (normally aircraft land on oposite direction in this airport, from land to sea direction but it was morning so I supposed there was wind in sea to land direction). The reverse thrust was applied just few seconds. Thank you for your channel, I’m not a pilot and I’m afraid of flight but thank to you I’m learning a lot :) greeting from Chile.
That would make sense for the winds in the morning to be in the landward direction though typically that is the prevailing coastal breeze every morning so it's odd that they would usually be landing the other way even in the morning. Granted landward after sunrise and seaward after sunset is the expected pattern resulting from differential heating and cooling rates of land and water but that said strictly speaking that would only be absolutely true ignoring other factors (ie if the atmosphere was always completely still otherwise). Guess it is possible that airport is in a location that is usually subjected to even stronger prevailing winds that overcome that effect. Well either that or simply observer bias if for example you usually flew in to that airport at a different time of day that would make the wind patterns common at that time of day seem more usual than they necessarily were.
Hi, I have a question. I've always wondered what would happen if you attempted to do a barrel roll in a full motion flight simulator? As the simulator floats on 4 hydraulic rams it can only pitch and roll the cabin to certain angles - it cannot physically turn the cabin upside down! So I'm assuming it would stop banking at a certain angle and remain there until the bank or pitch returned to within range. But if you continued to bank over vertical (so the plane is upside down), there will come a time where the bank 'as indicated in the flight deck' will be the opposite to the actual physical angle of the flight sim. Do you see what I mean? The plane will be at Left 60 degrees at the limit of the hydraulic rams, continue banking... 70 degrees, 80 degrees, 90 degrees (vertical) and continue rolling upside down. Impossible for the rams to place the flight sim at this angle. Then what if you just kept banking until the bank came back into the scope of the hydraulic rams, this would almost be in the opposite direction to where the rams were left - does it quickly flip to catch up? (hope that makes sense!). Anyway, that's my question if you are able to answer (perhaps in a new video?). Great videos by the way, always watch them.
Bank of the pod is NOT equal to the bank angle of the plane. In coordinated curves the is NO bank (at least as I understand it). Banking is used to give the acceleration sensation of uncoordinated curves. Say you drop a wing, but don't initiate the corresponding yaw, and even counteract the yaw that would be induced by roll-yaw-coupling with opposing rudder input. That makes the plane hang oddly in the air (and you in your chair, thus can be felt as a lateral acceleration). Simulating this acceleration is what the tilting mechanism is for. (Similarly back and forth for speed acceleration and braking.) In coordinated flight, the projected image is rotated to give the correct sensory feedback, not the pod. All that being said: A simulator of course can NOT simulate all the sensory feedback of aerobatics. Just imagine the g-forces in a loop or a tight curve. There's no way to simulate that for an extended time in a tethered pod.
Very interesting video, now I know what you are talking about when you say "reverse thrust" in any other video, although the name already indicates something like that ;) The dog is so cute!
He probably did confuse a lot of people. And he was wrong about that. He is confusing planning and safety factors with physics. Of course you don’t want to plan to need reverse thrust to stop before the end of the runway, but it’s undeniable physics that if they are applied, it will reduce the braking distance.
I found this fascinating and informative as an aeroplane geek, but I think your dog was bored senseless 😂 I think you should re-upload with subtitles for the pooch 😂😂😂
I was on a Delta flight from LAX to I think Minneapolis a number of years ago, I cant recall if it was an Airbus or a Boeing but it was a mid size (737, A320) twin engine jet. We had a thrust reverser on one engine unexpectedly deploy shortly after takeoff and it was quite unpleasant for a few moments, the plane yawed violently and lost a lot of altitude quickly. They managed to shut the engine down and we did a heavy landing with all the emergency crews back in LAX. A ex 767 pilot friend of mine tells me we were very very lucky to get away with that and it could easily have ended very badly. The most disturbing thing for me was that they never let us get off the plane, they just bolted the thrust reversers closed so they couldn’t deploy and sent us on our way, which also meant a very very long landing roll at the other end because they only had brakes.
The reverse thrust linked to "weight" on the landing gear was introduced, if i´m not mistaken, after the accident of a Fokker 100 aircraft - TAM airlines - in 1996, in Brazil, when the right reverse thrust opened as soon as the plane took off, causing its crash 24 seconds later...the pilots never had the chance to know what happened, once there was no alarm to this malfunction by that time. According to Northrop Grumman (engine manufacturer), this failure would happpen with a remote chance of "1: 100 billion" - well, they won the lottery as it seems - so the company thought it was unnecessary to inform the airlines and pilots about this possibility.
That accident was pretty shocking at the time, one of the deadliest in Brazil's history. I happened to live close enough to the airport at the time to see the smoke billowing from the crash. "According to Northrop Grumman (engine manufacturer), this failure would happpen with a remote chance of "1: 100 billion" " An excellent reminder that probability estimations have error bars, often very large ones.
On the C-130 Hercules you can't go into the beta range in flight. The C-130 the Navy landed on an aircraft carrier back in the 60s had the beta lock disabled so that the prop would be in reverse by the time it hit the deck. The C-17 does use its bypass thrust reversers to do high angle combat descends.
You can youtube C-17 airshow" and see it. Unfortunately, from the ground, it is a bit anti-climatic until they use the revereser to actually back up on the ground immediately after landing. Its hard to know a "steep combat approach" from a normal unless you actually fly them. In the plane however, it is a bit more exciting. Having a cargo plane that nose low with reversers out is... a different experience. C-17s are the only aircraft I know of that are built to deploy reversers in flight (and have procedures to do so). I could be wrong though... There may be some hot and spicy (chinese) or vodka (russian) flavored variants that can do it as well. I am biased... but I doubt they do it very well...
Can't go into reverse in flight on the C-130, P-3 Orion or C-2/E-2 aircraft. He's normally spot on in all of his videos, but this had me shaking my head more than a couple of times.
This is an excellent introduction to reversers. Some thoughts: 1. Wheel brakes and airbrakes might best described as "effective" rather than "efficient". Reversers are efficient with regard to their reversal of available thrust, but I'm not sure what an "efficient" wheel brake would be. 2. Reversers have been used for backing jets out of the gate at rustic terminals, this might be mentioned as an introduction to foreign object ingestion.
The Lauda Air 767 was powered by a P&W 4000 series engine that didn't use a weight on wheels sensor activation system. GE CF6-80C powered 767 aircraft use weight on wheel sensors, and will not activate in flight. The CF6-80C was modified for re-powering the The Lockheed C5B aircraft, becoming the C5M. There is/was a requirement to be able to deploy the reverser in flight. The reverser blocker doors, cascades, and link arms had to be beefed up. The translating cowling blocker door reverser is much more effective that the as you called them bucket reversers. In the industry, they're referred to as clam shell reversers. Clam shell reversers have short time on wing life due to heat impingement.
Excellent info, thank you! I always thought the clam shell reversers looked pretty bad in comparison to the more modern type. I can imagine the heat generated that close to the turbine is probably 1000s of degrees.
T/Rs on any 767 could not be activated in flight due to the 'squat switch' which senses whether it's on the ground or not. There is an electrical circuit that prevents T/R actuation in flight. Lauda's 767 had a malfunction of that control circuit. GE provided their own T/Rs while Boeing-Wichita built the Pratt T/Rs. I think Rohr built the Rolls engine T/Rs. GE's design was determined to be in compliance, but a supplemental mechanical sync lock was added to the Pratt and Rolls T/Rs to prevent a recurrence on a number of Boeing, Douglas and Airbus airplanes. I know, since I invented it and have the patent.
@@Greatdome99 Sadly, Lauda’s 767 was doomed by overconfidence by Boeing and a “single point of failure.” A rare (and thus extremely difficult to reproduce) failure in the T/R ISO Valve may have been the ultimate cause of the in-flight T/R activation, but just like the O-Rings in the SRB’s were the ultimate cause of the Challenger explosion, it was overconfidence that had become endemic in NASA’s culture which ended up putting repeated pressure on Morton-Thiokol to issue a “GO” over several concerns about the extreme cold weather and the known flaw. Flight safety shouldn’t require passenger deaths to get right; it shouldn’t be something that is narrowly defined as contingent on a failure being survivable in one specific aspect of flight. Absolutely I’m grateful for the improvements made, but the cost is simply too high.
@@Greatdome99+ The 747 and 767 Boeing aircraft are the first aircraft where Boeing didn't manufacture the nacelle in-house. Engine manufacturers were being held to meet fuel burn guarantee/promises. They own the package of engine, nacelle and thrust reverser. Boeing Wichita didn't manufacturer the Pratt 4000 series reverser, Rhor did down the Chula Vista CA. General Electric didn't manufacturer their own reverser. Martin Marietta in Middle River MD was the designer and built the reverser.
I hit this randomly, thought I'd be bored after a minute or two and move on, found myself totally engaged and watching the whole thing! Thanks for an interesting and informative video. (Now subscribed) Your dog is like "yeah i know all this already, when do we go the outside daddy?"
Mechanic here. You can trick most lockout systems by pulling certain circuit breakers and/or throwing certain test switches. Basically, you have to configure the aircraft so that it thinks it's on the ground, which... causes other very unsafe problems, but yeah, it can be done. We do lots of logic tests with aircraft on jacks, you'd be surprised what you can get them to do if you have a lot of specific system know-how.
SanctuaryReintegrate, wow.. impressed person here...you mean to say if you redirect or circuit those systems that you suddenly can do it? As in you take away or fool the systems that should prevent it? incredible! Thank you captain obvious...
Ask the crew and passengers of Lauda Air flight 004 when it fell out the sky from 30000+ feet due to one of the thrust reversers activated due to a faulty solenoid.
This was a sad accident. TAM Airlines flew a nice fleet of Fokker 100, one of them took off from São Paulo Congonhas airport. Reverser on the right engine deployed and the pilots did not have the training to overcome the situation. Auto thrust brought the lever to iddle, this would solve the problem, but the pilots did not link cause and consequence, so they forced the thurst lever to full power again, loosing control and crashing on some houses in the neighborhood.
I don't understand how reverse thrusts don't affect landing distance on dry land, like it's still a counter force, it SHOULD REDUCE , and in simulators thrust reversers actually can stop the plane
They still reduce landing distance, but runways at most major airports are long enough that they aren’t needed - instead, they’re simply used to assist the brakes in slowing the airplane down so the brakes don’t heat up as much.
When driving a car do you press the brake pedal as hard as possible every time you stop? If he goes full brake and full reverse thrust every time he lands a plane I doubt he'd have a job for long.
a little funfact about the traning of space shuttle pilots: Because the spaceshuttle is comperatively not very aeroydynamic, it has a 20° initial approach glideslope at 300knots and a decent rate of 10.000ft/min. To simulate that they train in a Gulfstream II jet with the gear extended and the engines in reverse.
I'm happy to hear that the safety checks for thrust reversers have gotten better! The FlightChannel produced an animated video on the Lauda air flight 004, and since then I haven't been able to not think about that accident while on a plane. I'm a long time fearful flyer, but it's not the turbulence that bothers me, it's all the minute details that could go wrong and set off a chain reaction in flight that could produce an accident. Like how on JAL 123 a cracked fan blade caused that entire thing. Thanks for explaining this!
Sir, haven't they yet contacted you for teaching at a Flight Academy or so? Very seldom do someone get my attention and respect as you do. Very sharp thinking, so eloquent speaking. Best of luck in your pursuits, and may God keep you safe.
Does reverse thrust in dry and hot conditions really not minimise the landing distance? In my undestanding of physics, its just one more force added to the others like spoilers and brakes to slow down the aircraft. I really think you will achieve the shortest landing distance with all forces combined, including reverse thrust, no matter if its dry and hot. But maybe I am wrong here. An answer would be super helpfull :D Great video as always :D
Flaps produce lift.......essential at slower speeds. Ground spoilers destroy lift, therefore gluing the aircraft to the ground.....again, they're essential and help to slow the aircraft down. I agree that with brakes, reverse thrust and ground spoilers combined you'd achieve the shortest landing distance
I had the same confusion, but I think he means there is no difference *for the same landing distance*. The thrusters add more force, so the brakes can work less to stop in the same distance.
Spoilers do very little to stop the airplane. You are right, it is the combined use of all braking systems that maximizes stopping power. That's why you'll notice, if you hang out at an airport and watch some landings, that the pilots use both brakes and thrusters to stop passenger planes.
@@jameskoralewski296 The primary purpose of the ground spoilers is to maximise wheel brake efficiency by "spoiling" or dumping the lift generated by the wing and thus forcing the full weight of the aircraft onto the landing gear. The spoiler panels also help slow the aircraft by producing aerodynamic drag.
I remember we had 2 or 3 aborted takeoffs in a Sabena A310 out of Dakar around 1983. I was in the front seat in business class and saw the captain leaning out of the door and looking back at the port engine. I said hello and asked what was going on and he apologised for not getting us back to Brussels. he said he kept getting a reverse thrust warning light on one engine before V1. I laughingly said 'I like it here' let's just stay'. That is what happened, in fact as the crew were running out of hours and the engineers needed more time to be sure that the problem was a faulty indicator. One engine going into reverse would have been fatal. There was also a big gap between attempts in order to let the brakes cool.
Old fashioned "organic" (asbestos) brake linings were efficient when cold then as they heat up they become less efficient - "fade." Full metallic brake linings on the other hand are inefficient when cold then as they heat up they become more efficient. For highway cars a compromise is made to balance between cold/hot by mixing metal "shavings" in the organic material - "semi-metallic" brake linings for more consistent brake performance.
That works for disc brakes but not for drum brakes. When heated the drums expand away from the shoes. It doesn't matter what the brake lining is of it isn't applying pressure to the opposite surface.
Another accident with thrust reversers deployed in flight (in fact, during takeoff) was the TAM flight 402 in 1996 in Brazil. The thrust reversers kept deploying contrary to pilot's will, which in turn led the aircraft into an asymmetric thrust that led it to a stall mid takeoff.
The strength of that pylon holding the engine is incredible. You'd think with all that force, that it would snap off the wing. Great video! Cute dog. 😀
@ electron. it's not just the pylon...
the engine is mounted onto the pylon / wing via explosive bolts...!! the bolts are used to secure ie hang the engine to the pylon / wing BUT at same time are designed to shear off and "release" ie let go of engine in case of accident, so that the engine would not rip the wing apart..!!
@@bahardin3992 I know all that already.
@@electronicsNmore that could have been politer
@@fastflight2494 it was polite, I didn't put an exclamation point after what I said.
@@electronicsNmore fair point. Sorry about that
I understand that this is mostly directed to new pilots who are just beginning to learn their craft,but it is immensely fascinating to those of us who aren’t and probably will never be pilots.
'First officer doggo' is adorable 🐕💜
MaltaMcMurchy Tyats the captain fool
@@woaa8117 Yeah, he's the captain.
I also like to watch these dog videos 🥳 They are brilliant 👍
1. That dog is alive.
2. Most of his videos start off sounding as if he is speaking German.
3. Cool vid.
He is Swedish, so it honestly isn't that strange.
@Honkler In that case Dutch and Swedish accents in English sound similar to you. Most Swedes who speak English with a bit of an accent sound like that.
He is Hitlers grandson
@Honkler Echt niet.
it's interesting isn't it, considering he's Swedish. lol
I was in a DC8 many years ago. The pilot wanted to quickly lose altitude to avoid a thunderstorm and reversed thrust in flight to quickly land. I was amazed while none of the other passengers seemed to understand what was happening. Never forgot it.
Alan Snider DC 8s can reverse the inboard engines as they do not have speed brakes
@@charliebrown6161 A DC-8 most certainly does have spoilers (aka speed brakes). Erroneous deployment of the spoilers shortly before landing in Toronto is what crashed Air Canada flight 621, a DC-8, in July 1970, killing everyone on board.
@@HartmutWSager I worked on the DC8 some years ago and although I agree about reverse thrust, I do not recall and airbrakes.
@@HartmutWSager There are quite a few variants of DC-8 with radically different features. Some criticism of that denzel film with the extinguisher for example not cutting the engines, genuinely was possible on that earlier style of DC-8.
In this case only the first few out of the factory had airbrakes, as it was removed before full deployment.
@@carbon1255 Indeed, there are quite a few variants of DC-8 with different features, just like there are in most other plane series too, but are we even talking about the same item here? You have again referred to "airbrakes", which I took as a mislabelling of "speedbrakes", which itself is a mislabelling of spoilers. If you are referring to spoilers, practically every large jet aircraft of the last 70 years has them (to diminish lift right after touchdown). Otherwise, what are you referring to with "airbrakes"? Obviously not the reverse thrust mechanism (though the term "airbrakes" might be apt there), since you are separately referring to reverse thrust. Please clarify.
Love your logo! But, you didn't want to "be dated" with Carbon-14? No spare neutrons handy?
As an aircraft engineer myself I love your vids. It's interesting to see a pilot with your level of mechanical knowledge. Great job highspeed
The Lauda air plane, that crashed was called " Mozart".
I flew with her the same route from Vienna to Sydney one year before the accident happened.
She was brandnew. I never felt so safe.
Couldn't believe it when it happened.
I sat in this beauty.
All the flight attendants were beautiful modells from the catwalk.
So sad! This crash destroyed the upcoming " Lauda Air".
Can only imagine how amazing that was. FAs now on US airlines are generally the opposite of runway models. Nikki Lauda clearly knew how to run a class operation
It’s absolutely amazing the amount of knowledge needed to know to fly a ✈️. Love the videos and the 🐕
Your dog is like "There is no one in the room. Who is he talking to?" 😅
They don't judge their humans for mental conditions. The good doggos just trust we're talking to someone they don't see.
Owner talking to the people in his wall again
I love how well you explain in detail. Thank you for taking your time to explain the detail. !
I just have to say, I found this channel only because of my interest in supersonic air travel and interest in the Concorde and thanks to a couple of your high quality videos on the subject, I continued watching more and more of your videos any time I have a question or curiosity regarding air travel. Your content is phenomenal! I'm borderline addicted to your videos, I can't stop watching, they all seem so interesting and captivating!
Also, I'm a huge automotive enthusiast and it's interesting to see how much translates from the auto world to the aircraft world. I have a pretty good understanding of a lot of things you talk about, such as when you talked about brakes and braking in this video.
I was a passenger on a DC8 where the thrust reversers broke off on one engine immediately upon landing in Calgary many moons ago. The aircraft crabbed sideways and hopped up and down in the air. Rather scary. I was on a flight from Vancouver to Montreal and after 8 hours of waiting while they were repairing, they announced they were transferring us to another aircraft and we all cheered.
That was always a thought of mine. What if one side fails. Do you careen down the rest of the runway like a childs pinwheel.
This actually happened a while ago on a 767 in mid-flight and during cruising, it caused a massive bad chain of events. The aircraft reached extreme G-forces and then broke up and crash into a mountain range, unfortunately, killing all on board.
Lauda air was the airline !but nikki the owner found the fault and got compensated by Boeing !
As in Niki Lauda the F1 legend?
First time I watch one of your videos, and was impressed you knew the 10ft or below radar alt thrust rev deployment was possible. I know guys licenced on type who don't believe me when I tell them that. After the Lauda incident, there were two AD's I distinctly remember directly related to that crash, that came out on the B732's I was working on at that time. One was a mechanical lock on it's JT8 buckets and the other had to do with passenger seats. I once watched a BA B744 have 2 engines go into uncommanded thrust rev right after rotation. The mechanical locks that were incorporated on the RB211 after the Lauda crash meant the reversors only extended about 2 inches before mechanically locking. Of course the power automatically reduces in said engines, but she was able to climb out with full pax and around 118 tons of fuel. I say around 118 tons, because thats what we used to fuel our B744 for the same route.
The dog must be thinking jees my owner talks to himself a lot.
Lol
That's what I thought
I commented this same thing on one of his other videos the other day 🤣
I bet he wishes that he would talk about dog biscuits!
@@heididietrich9800 Dog biscuits and a long walk in the park.
As always, your explanations are on point and very well for me as a "normal" curious passenger to understand. Thanks for taking all the time and patience! :)
Love your show! Very well explained..... my curiosity has been answered.... I’ve always been fascinated by the subsequent investigations of air-crashes and how the industry seems very committed to understanding and improving the engineering of airliners, pilots and processes. Nice to know that you’re also keen about understanding. Keep going!
On the DC-8 you don't have in flight spoilers / speed brakes to slow down the plane on descend. The plane only has ground spoilers that activate when you have weight on wheels. In flight you can engage the reverse thrust on the inner (n 2 and 3) engines. It's a interesting plane to fly compared to more modern designs.
True - I got my flight engineer rating on the DC-8 and you could use idle reverse inflight on the #2 and #3 engines. Some crews would not do it, and Douglas apparently was concerned enough about a stuck reverser inflight that they put an "emergency stow" switch on the captain's overhead panel.
When the propellors change pitch angle to reverse thrust there must be a huge amount of pressure at the hub bearing for a few seconds. Been in a turbo prop and you can feel like you are being wrenched out of your seat for a moment until the aircraft slows down.
Love the moving cuddly toy beside you, very realistic, looks like a real dog trying to get affection from his master 😀😀
Love your doggie - what a proper little teddy bear, so cute!!! 🐶🐶
He should have his own channel
Farlig66 ya he treats the doggie like a teddy bear an inanimated object. Should give some video time to the dog by petting the dog giving it some attention .
At 11:44 the dog has the same reaction as my GF has every time I’ll start talking shop
The doggo so cute
He is indeed.
Mentour Pilot yesss lol
He'd do a great First Officer.
Pet the damn dog!
He's cute, but he needs less caffeine :)
Short answer: the plane flies back to the departure point and everybody gets their money back.
Viktor Kaganovich 😂😂😂
and happily ever after, the end
Wow Thumbs up there
Or worse, goes even more back to every other flights
Viktor Kaganovich lmao good one brother
I had asked myself this question myself when I accidentally engaged reverse thrust in X-Plane 11 today. Great video.
Murphy The Gamer l like your dog
Thank you for mentioning that the DC-8 can deploy thrust reversers and descend rapidly. I remember reading about this in an aviation magazine in the mid to late 1960's. Now, my pilot friends can stop thinking that I made it up. Happy Landings, Mack
I never realized how interesting all this stuff is, I like it.. Thanks
Your dog is cracking me up! He's just laying there like a kid
Awesome video!! Answered all my questions 😁
EveryTypeOfVideo 😀
Excellent!! I’m happy to hear that
Correct me if i'm wrong, applying reverse thrust allows you to reduce brake's input and thus limit heat's rise. But if you apply maximum reverse thrust and maximum brake, aren't you supposed to stop faster?
There's no point in that if you stop short of the taxiway.
@@Markle2k his point is, that the guy in the video said that reverse thrust makes zero difference on a dry runway, which makes no sense.
I agree with Slyze33, applying thrust reversers on full and full brakes WILL DEFINITELY shorten the landing distance. Mentour clearly said there is no difference.. This does not compute!! Maybe we are missing something here.
@@ashwinmohan4503 the brake settings specify a rate of deceleration, so from a pilots point of view the statement is correct. The pilot won't actually decide how hard the brakes are worked he only decides how fast he wants to stop.
@@stefan514 The "guy in the video" is an instructor pilot for an airline. I agree that it wasn't phrased as well as it could or should have been, but the context is "what do we do in line operations?". This isn't a video or a channel for people who are interested in 130-0 deceleration runs with $100M aircraft for shits and giggles.
The answer is, "we use reverse thrust to reduce stress on the wheel brakes" which is EXACTLY what he said in the video.
He’s so cute! Look at him biting his paw😆
?
OMG, L-O-V-E your sweet dog! What a complete doll 😍😍😍
Patxi is such an adorable pup ❤️
He definitely is. Laying here with me right now.
he's really working the camera in this one ! lol
Patxi? Are you a bask country lover? :)
@@MentourPilot
Pretty soon, Patxi is going to need to hire his own agent! He could have his own TH-cam channel!
what is this breed? very sweet.
Don’t know if it’s still done this way, but when I was flying the Jurassic and classic B-737’s runway RTO and landing figures were based on brakes only so T/R added a safety measure. Not to imply they don’t reduce landing distances because they do quite well. We used to power out of some gates on rare occasions when a tug was not available. As for deploying the T/R before touchdown, besides being a bad idea a pilot considering it should fly/land that particular airplane a few times beforehand to confirm the T/R deploy simultaneously. If they’re not synchronized which happens you’ll hit the ground on the side that deploys first. Maybe to the point of damaging the A/C.
I remember the Lauda Air incident well. As far as I remember the pilots had the time to check the handbook, when the indicator for the thrust reverser came on - and it stated that there is no action necessary. So they probably might have had time to shut down the engine before losing complete control - if they would have known that this is the correct action. I think Boeing until then believed, that such an incident would not be possible and that the thrust reverser indicator could only be a malfunction of the panel. Tragic mistake.
Niki Laude proved then in many simulator tests, that the pilots had no chance to regain control and the fault was clearly with Boeing.
Thanks again for the great video! And your dog is just lovely!
The pilots reduced power to idle and even cutoff the fuel, but not fast enough. In the sim, they showed that the crew would only have 3-4 seconds to shutdown the engine before a catastrophic failure. They missed that window by only a couple seconds. Extremely tragic. Niki Lauda is a hero, forcing Boeing to fix this problem once and for all.
Bits of what I think is the CVR to that crash are on here.
I always love it when the thrust reverse is used, especially when it's wet out. Sounds and feels amazing. I'd be the guy craning his neck to look at the engine haha
Same same
Lauda air 004 is worth a mention, among others. Thrust reversers have interlocks on them now because there have been a few accidents due to inadvertent deployment.
"It deployed!"
He mentions it 17:31
Yet puppy is back yet again!
Love these videos.
I don't understand how reverse thrust has 0 impact on stopping distance if it's the only thing that slows you down on a wet runway.
What I gathered is that they use reverse thrust to (partly) replace braking instead of using using both at max. So they don't try to reduce stopping distance, maybe because that would just increase the distance they have to taxi, maybe because that would be uncomfortable. If they would rely on a combination of reverse thrust and braking to land on a short runway, you've also got little margin for error. One sudden rain and you're no longer able to land.
@@DutchBlackMantha That is okay, so it is not calculated like that, but the question is not why they do not use it to further reduce stopping distance, but why is that has zero impact on it. This part is also not clear for me. If you can stop the plane with brakes on the same distance as you can stop it with reverse trust /okay, not exactly/, then adding the two up together should reduce the stopping distance. So once again, I understand that they do not do it, and I understand why they do not do it, so my question is more related to physics than let's say logic.
It doesn’t make sense, because he’s wrong about that part. He is confusing planning and safety factors with physics. Of course they don’t want to plan that reverse thrusting will reduce braking distance, because if it fails, they may not be able to stop safely. But any time reverse thrust thing is being used, it absolutely does reduce braking distance. That is just undeniable physics.
@@bobbyjbobbyj Yeah he missed that part of the explanation. If its done in dry conditions why would the breaks not get as hot? Because the reverse thrust took some of the kinetic energy the brakes otherwise had to suck up all by themselves. And if you would apply max brakes and max reverse thrust you wouild stop sooner but with hotter brakes.
@@albinfiskare I understood that part. I was also confused, he explained it like even if you had max breaks and full reverse, you would take up the same stop distance as just full breaks. That part didn't make sense.
The DC-9 series 30 actually always deployed their thrust reversers in flight as a matter of routine. Watch videos of the “9’s” landing. Take note when the reversers are deployed. You should see they are deployed after the mains are on the ground but before the nose is on the ground. We would pop the reversers without adding power on touch down and let the drag of the reversers gently lower the nose to the ground. Once the nose was on the ground, we then would add power to provide negative thrust.
The DC-9 is not officially on the ground until the nose is down. That is because it did not have a WOW switch on the mains as with most other large commercial aircraft. It has a “Ground Shift Mechanism” on the nose gear. So as far as the aircraft knew, we were deploying the reversers while the aircraft and all the systems were still in the air.
The longer series 80 DC-9’s didn’t do this because the engine exhaust were so close to the ground at landing attitude, the reversers would actually strike the ground if deployed and break off. This fact was learned the hard way by Hawaiian Airlines.
"As a matter of routine"? Hardly. The aircraft operating manual prohibited it, and a captain would be disciplined by the company, if detected or reported. Also, he would be in serious trouble if he had to cancel the reverse for a go around, in which case a full 8 seconds would be required for the engine to transition from reverse idle to take off thrust. I also have a type rating (And 8,000 hours) in the BAC 1-11, with the Rolls-Royce Spey engine, which was approved for use of reverse thrust in flight, as the idle to full spool-up time was only 2.8 seconds, as quick as propeller thrust. It was also approved for the use of idle power on approach, because of that advantage. This resulted in very quiet landings, with no reverse and long roll-outs, traffic permitting, and the terminal was at the far end of the runway. (10L at PIT, for example)
And, if you're wondering, Mohawk, Allegheny, USAir.
I enjoyed this video very much (and your dog is awesome). This topic has been on my mind for some time:
About a decade ago I caught a ride on my employer's Citation III. It was a long flight, and I was sitting in the back row by myself. Out of curiosity I started opening cabinets in the head-compartment and found the flight manuals. I'm an aviation fan and an engineer so I was drawn to the manual labeled "Emergency Procedures." I opened to a random page and the first thing I saw was "Inadvertent In-Flight Deployment of Thrust Reverser." The thought that something like that could happen had never entered my mind. My brain did a quick calculation of the moment that would be created if one side deployed at speed while the other did not. All I could picture was our pretty plane turning into a Frisbee. I'm not a nervous flyer, but this was enough to make me put the manuals back where they belonged and return my attention to the novel I had been reading.
Wow I’m blown away - not the force of the reverse thrust, but didn’t expect this to be such a large topic
When I was in my early 20s, I am now in my mid 50s, I flew from Orange County, CA. to Sacramento Metro on an Embraer Brasilia. When the pilot was entering the landing pattern he did, in fact, bring the prop pitch in to beta. Whether by mistake, or because he needed to slow the aircraft quickly. I was sitting just behind the port wing, and had a clear view of the port engine. I could hear the change in prop sound, I could see the change in the prop silhouette, the engine did begin to shudder significantly, and visibly, and I could feel very significant deceleration over many seconds. I have since asked a few airline pilots about this, and have been told that this would NEVER happen, but I know what I experienced. I think that those pilots were just talking the party line. At the time this event occurred, I did already have some small aircraft flight experience.
I have not before, or since, experienced that sort of deceleration over such a long period of time. I can say that it was quite an effective way to slow the aircraft.
The dog is like: huh rejected take off? How about rejected me :(
Mark Grudt -- :-)
My dogs show up to band practice and lay out in the middle of the floor...
Labs. Gun dogs. Not afraid of noise AT ALL. I have one that follows me around when I vacuum.
Let me sum this us.
"We use thrust reverse because there is no reason not to"
Basic physics in play for frictions both for safety and for efficiency of the aircraft.
Great video.
Thought airlines sometimes skip reverse thrust to save fuel (assuming they've calculated that the runway length is sufficient for safe braking)
Thank you for answering this question, and your dog is wonderful :D
I love how you have different videos than captain joe so I get to watch both channels and learn new things
But what I really want to know is when the runway is dry and you enable reverse thrust and there is loads of air driving forward why doesn’t that slow down the plane but when it’s wet it does. I understand how the brakes work and that they need cooling but when it’s wet why do the reverse thrusters slow down the plane but not when it’s dry 🤷♂️
Please like so this can be answered
Thanks
He's overgeneralizing or not explaining fully. When it's dry the thrust reversers will obviously still provide a force which will slow the plane more, it just isn't nearly as big of an influence when it's dry versus wet. Just like when it's wet you'll still get braking force even though it's less but it's not zero.
David Landon ok thanks so much for your help final question why is there a difference in the amount of thrust when it’s dry compared to wet is it due to the fact they just add more power?
@@tomwhyte Air conditions affect the power of engines in a few ways. Colder is more power because denser air, some water can actually add power because it expands into steam but that's a fairly small increase. As I understand it wet conditions shouldn't impact power significantly.
@@dlandon2000 Effects of humidity on turbine engine performance have been extensively tested. Moisture content itself has no direct effect on combustion, however atmospheric conditions associated with humidity have a negative effect on performance due to decrease in air density associated with rise in humidity.
Condensed moisture is a bit different in the fact that H2O as a liquid is non-compressible, and therefore has even more of a negative impact on turbine engine performance due to volume it occupies in the compressor stage that could be compressed air. This reduction in total air(oxygen) has the same negative effects as lower air density on overall thrust/performance that is not offset by said moisture changing back to steam.
Tom, it is explained, watch again ;-)
"Reverse thrust is not used to reduce the distance but to help reduce heat on brakes" means that they do not try to get the shortest distance and rather use the same distance, applying less brakes, thus generating less heat (you know, the time needed for the discs to cool down versus the short time available between rotations...).
On the other hand, on wet runway, the brake on wheels is poor since the anti-skid releases the brake to avoid loss of control and going out of runway. You can compare that to the ABS on a car (with the difference of the amount of energy -mass/speed- involved). So you need an alternative way to kill speed AND keep on the runway; the reversers slow you down and the wheels keep the trajectory. Remember the planes wheels are quite slick and really subject to aquaplaning, then the job of braking is transfered to reversers so less adherence is required for the wheels. In wet conditions, heat is a lesser issue than on hot dry days.
So, wet or dry runway, reversers actually slow down the plane, but for different purposes than shortening the distance.
Hope this helps.
I'm not fan of poodles, but I love dogs and yours seem to be a lot of fun !
Actually, the Space Shuttle trainer aircraft, a highly modified Gulfstream 2, had the capability of reverse thrust in flight. Not sure if it came that way or if they modified for that. But, they took astronauts up to 38,000 feet and threw the engines into reverse to simulate the rate of descent of the orbiter. Normal glideslope for an airliner is about 3%, for the orbiter, it was about 22%. That's headed downhill quite fast.
Thank you take care your self 2. As always you're simply the best instructor & personality. Thanks
the concept of thrust reversers is very well explained.
Dog: "I'm living the dream!"
I want to be that dog when I grow up.
Really. Looks bored. Wants a scratch a snack a walk a bitch anything
A trust reverser would be if you got on the intercom before flight and said “Hello, this is uuhhhh your captain speaking, and uuuuuhhh this is my first day as a captain uuuuuhhh have a nice flight”.
Slaphappy Duplenty hahahaha 👍🏻
epic!
You very clever
I'd be able to relax under those conditions. If he said it was his first day as first officer, I'm boarding the next flight. I don't know of any crashes where it was the first officer's first day, and I don't want to learn of one through first hand experience 😂
Hahahaha
7:34 the dog is so cute :D
I love your videos and find them fascinating, and hanging on every word you are saying but I am totally watching your dogs the entire time. They are freaking adorable and stealing the scene from you.
Bruh your dog is just too cute in this video even looks at us to make sure we are listening!! 💕
Once i saw the engine “open” just before landing. I was really scared. Then, I looked over thrust reverse and finally figured out what I saw. It occurred about 1-2 min before landing, and I assume the put it because of excessive landing speed (normally aircraft land on oposite direction in this airport, from land to sea direction but it was morning so I supposed there was wind in sea to land direction). The reverse thrust was applied just few seconds.
Thank you for your channel, I’m not a pilot and I’m afraid of flight but thank to you I’m learning a lot :) greeting from Chile.
That would make sense for the winds in the morning to be in the landward direction though typically that is the prevailing coastal breeze every morning so it's odd that they would usually be landing the other way even in the morning. Granted landward after sunrise and seaward after sunset is the expected pattern resulting from differential heating and cooling rates of land and water but that said strictly speaking that would only be absolutely true ignoring other factors (ie if the atmosphere was always completely still otherwise). Guess it is possible that airport is in a location that is usually subjected to even stronger prevailing winds that overcome that effect. Well either that or simply observer bias if for example you usually flew in to that airport at a different time of day that would make the wind patterns common at that time of day seem more usual than they necessarily were.
13:11 for the actual title question
thank you
lol
Thx
When I pressed the time stamp an ad pupped up
People like you need to be appreciated
Hi, I have a question. I've always wondered what would happen if you attempted to do a barrel roll in a full motion flight simulator? As the simulator floats on 4 hydraulic rams it can only pitch and roll the cabin to certain angles - it cannot physically turn the cabin upside down! So I'm assuming it would stop banking at a certain angle and remain there until the bank or pitch returned to within range. But if you continued to bank over vertical (so the plane is upside down), there will come a time where the bank 'as indicated in the flight deck' will be the opposite to the actual physical angle of the flight sim. Do you see what I mean? The plane will be at Left 60 degrees at the limit of the hydraulic rams, continue banking... 70 degrees, 80 degrees, 90 degrees (vertical) and continue rolling upside down. Impossible for the rams to place the flight sim at this angle. Then what if you just kept banking until the bank came back into the scope of the hydraulic rams, this would almost be in the opposite direction to where the rams were left - does it quickly flip to catch up? (hope that makes sense!). Anyway, that's my question if you are able to answer (perhaps in a new video?). Great videos by the way, always watch them.
I'd be curious to know that as well.
i hope it ejects you out of the room, with extreme prejudice for being an idiot.
Bank of the pod is NOT equal to the bank angle of the plane. In coordinated curves the is NO bank (at least as I understand it). Banking is used to give the acceleration sensation of uncoordinated curves. Say you drop a wing, but don't initiate the corresponding yaw, and even counteract the yaw that would be induced by roll-yaw-coupling with opposing rudder input. That makes the plane hang oddly in the air (and you in your chair, thus can be felt as a lateral acceleration). Simulating this acceleration is what the tilting mechanism is for. (Similarly back and forth for speed acceleration and braking.)
In coordinated flight, the projected image is rotated to give the correct sensory feedback, not the pod.
All that being said: A simulator of course can NOT simulate all the sensory feedback of aerobatics. Just imagine the g-forces in a loop or a tight curve. There's no way to simulate that for an extended time in a tethered pod.
Interesting question!
mrmattandmrchay the I
Very interesting video, now I know what you are talking about when you say "reverse thrust" in any other video, although the name already indicates something like that ;)
The dog is so cute!
Highly informative, you answered a question I always had and wanted to understand for a long time. Thanks
When you said that "on a dry runway the thrust reversers don't reduce the landing distance at all", I think you confused a lot of people.
James Barca Of course the thrust reversers do work the same, it doesn't matter if the runway is wet or dry. Anti-physical bullshit.
WET OR DRY the reverse's come on..
He probably did confuse a lot of people. And he was wrong about that. He is confusing planning and safety factors with physics. Of course you don’t want to plan to need reverse thrust to stop before the end of the runway, but it’s undeniable physics that if they are applied, it will reduce the braking distance.
I found this fascinating and informative as an aeroplane geek, but I think your dog was bored senseless 😂
I think you should re-upload with subtitles for the pooch 😂😂😂
Mentour, you and your canine co-star do a great double act . . .
DUUUUUDE, I never would've thought about using them to cool the brakes! That's fabulous
I was on a Delta flight from LAX to I think Minneapolis a number of years ago, I cant recall if it was an Airbus or a Boeing but it was a mid size (737, A320) twin engine jet. We had a thrust reverser on one engine unexpectedly deploy shortly after takeoff and it was quite unpleasant for a few moments, the plane yawed violently and lost a lot of altitude quickly. They managed to shut the engine down and we did a heavy landing with all the emergency crews back in LAX. A ex 767 pilot friend of mine tells me we were very very lucky to get away with that and it could easily have ended very badly. The most disturbing thing for me was that they never let us get off the plane, they just bolted the thrust reversers closed so they couldn’t deploy and sent us on our way, which also meant a very very long landing roll at the other end because they only had brakes.
Wow that sounds so horrifying and the solution so dodgy?
The reverse thrust linked to "weight" on the landing gear was introduced, if i´m not mistaken, after the accident of a Fokker 100 aircraft - TAM airlines - in 1996, in Brazil, when the right reverse thrust opened as soon as the plane took off, causing its crash 24 seconds later...the pilots never had the chance to know what happened, once there was no alarm to this malfunction by that time. According to Northrop Grumman (engine manufacturer), this failure would happpen with a remote chance of "1: 100 billion" - well, they won the lottery as it seems - so the company thought it was unnecessary to inform the airlines and pilots about this possibility.
That accident was pretty shocking at the time, one of the deadliest in Brazil's history. I happened to live close enough to the airport at the time to see the smoke billowing from the crash.
"According to Northrop Grumman (engine manufacturer), this failure would happpen with a remote chance of "1: 100 billion" "
An excellent reminder that probability estimations have error bars, often very large ones.
On the C-130 Hercules you can't go into the beta range in flight. The C-130 the Navy landed on an aircraft carrier back in the 60s had the beta lock disabled so that the prop would be in reverse by the time it hit the deck. The C-17 does use its bypass thrust reversers to do high angle combat descends.
Id love to see that video
You can youtube C-17 airshow" and see it. Unfortunately, from the ground, it is a bit anti-climatic until they use the revereser to actually back up on the ground immediately after landing. Its hard to know a "steep combat approach" from a normal unless you actually fly them.
In the plane however, it is a bit more exciting. Having a cargo plane that nose low with reversers out is... a different experience.
C-17s are the only aircraft I know of that are built to deploy reversers in flight (and have procedures to do so). I could be wrong though... There may be some hot and spicy (chinese) or vodka (russian) flavored variants that can do it as well. I am biased... but I doubt they do it very well...
Can't go into reverse in flight on the C-130, P-3 Orion or C-2/E-2 aircraft. He's normally spot on in all of his videos, but this had me shaking my head more than a couple of times.
This is an excellent introduction to reversers. Some thoughts:
1. Wheel brakes and airbrakes might best described as "effective" rather than "efficient". Reversers are efficient with regard to their reversal of available thrust, but I'm not sure what an "efficient" wheel brake would be.
2. Reversers have been used for backing jets out of the gate at rustic terminals, this might be mentioned as an introduction to foreign object ingestion.
Thumbs up for the pup! Great explanation, love your videos, thanks for sharing...
Amazing that he does these in one take.
The Lauda Air 767 was powered by a P&W 4000 series engine that didn't use a weight on wheels sensor activation system. GE CF6-80C powered 767 aircraft use weight on wheel sensors, and will not activate in flight.
The CF6-80C was modified for re-powering the The Lockheed C5B aircraft, becoming the C5M. There is/was a requirement to be able to deploy the reverser in flight. The reverser blocker doors, cascades, and link arms had to be beefed up.
The translating cowling blocker door reverser is much more effective that the as you called them bucket reversers. In the industry, they're referred to as clam shell reversers. Clam shell reversers have short time on wing life due to heat impingement.
Excellent info, thank you! I always thought the clam shell reversers looked pretty bad in comparison to the more modern type. I can imagine the heat generated that close to the turbine is probably 1000s of degrees.
T/Rs on any 767 could not be activated in flight due to the 'squat switch' which senses whether it's on the ground or not. There is an electrical circuit that prevents T/R actuation in flight. Lauda's 767 had a malfunction of that control circuit.
GE provided their own T/Rs while Boeing-Wichita built the Pratt T/Rs. I think Rohr built the Rolls engine T/Rs. GE's design was determined to be in compliance, but a supplemental mechanical sync lock was added to the Pratt and Rolls T/Rs to prevent a recurrence on a number of Boeing, Douglas and Airbus airplanes. I know, since I invented it and have the patent.
@@Greatdome99 Sadly, Lauda’s 767 was doomed by overconfidence by Boeing and a “single point of failure.” A rare (and thus extremely difficult to reproduce) failure in the T/R ISO Valve may have been the ultimate cause of the in-flight T/R activation, but just like the O-Rings in the SRB’s were the ultimate cause of the Challenger explosion, it was overconfidence that had become endemic in NASA’s culture which ended up putting repeated pressure on Morton-Thiokol to issue a “GO” over several concerns about the extreme cold weather and the known flaw. Flight safety shouldn’t require passenger deaths to get right; it shouldn’t be something that is narrowly defined as contingent on a failure being survivable in one specific aspect of flight. Absolutely I’m grateful for the improvements made, but the cost is simply too high.
@@Greatdome99+
The 747 and 767 Boeing aircraft are the first aircraft where Boeing didn't manufacture the nacelle in-house. Engine manufacturers were being held to meet fuel burn guarantee/promises. They own the package of engine, nacelle and thrust reverser.
Boeing Wichita didn't manufacturer the Pratt 4000 series reverser, Rhor did down the Chula Vista CA.
General Electric didn't manufacturer their own reverser. Martin Marietta in Middle River MD was the designer and built the reverser.
The little dog is saying I've heard this before and he's facepalming lmao cute dog
Pornographers
The dog is boring, I know.
doggie was cute when she was a small puppy, and she is still cute! :)
I hit this randomly, thought I'd be bored after a minute or two and move on, found myself totally engaged and watching the whole thing! Thanks for an interesting and informative video. (Now subscribed)
Your dog is like "yeah i know all this already, when do we go the outside daddy?"
Excellent video as always. These just keep getting better and better.
Peter i appreciate your hard work and videos, i just downloaded your paid ap sort of appreciation to your work.keep it up Sir
Mechanic here. You can trick most lockout systems by pulling certain circuit breakers and/or throwing certain test switches. Basically, you have to configure the aircraft so that it thinks it's on the ground, which... causes other very unsafe problems, but yeah, it can be done. We do lots of logic tests with aircraft on jacks, you'd be surprised what you can get them to do if you have a lot of specific system know-how.
SanctuaryReintegrate, wow.. impressed person here...you mean to say if you redirect or circuit those systems that you suddenly can do it? As in you take away or fool the systems that should prevent it? incredible! Thank you captain obvious...
@@Hermanos22 No problem, man. Always happy to share.
the dog is like "look at me, im so cute" * stares at the camera * "are you looking??"
Greetings from Thailand! Lauda Air 004 has occurred here.
That dog is living his best life now 😊
Ask the crew and passengers of Lauda Air flight 004 when it fell out the sky from 30000+ feet due to one of the thrust reversers activated due to a faulty solenoid.
@Bernhard Jordan Indeed - but *much* lower altitude.
This happened right after V-2 on a flight from Sao Paulo to Rio (in Brazil), and everyone on the twin-engined airliner died.
This was a sad accident. TAM Airlines flew a nice fleet of Fokker 100, one of them took off from São Paulo Congonhas airport. Reverser on the right engine deployed and the pilots did not have the training to overcome the situation. Auto thrust brought the lever to iddle, this would solve the problem, but the pilots did not link cause and consequence, so they forced the thurst lever to full power again, loosing control and crashing on some houses in the neighborhood.
I don't understand how reverse thrusts don't affect landing distance on dry land, like it's still a counter force, it SHOULD REDUCE , and in simulators thrust reversers actually can stop the plane
The could be used to reduce the landing distance, but instead are used to reduce the braking effort and save wear and heating on the wheel brakes.
Perhaps thrust reversers are not any more effective than wheel brakes on a dry surface?
They still reduce landing distance, but runways at most major airports are long enough that they aren’t needed - instead, they’re simply used to assist the brakes in slowing the airplane down so the brakes don’t heat up as much.
Some thrust reversers can actually back up a plane from a standing position.
When driving a car do you press the brake pedal as hard as possible every time you stop? If he goes full brake and full reverse thrust every time he lands a plane I doubt he'd have a job for long.
I watch your hilarious adorable pup while listening to you. Lol great videos! Thanks
A Brilliantly erudite discourse, thank you for taking the time to share this information, greatly enjoyable, safe journey always, best wishes
a little funfact about the traning of space shuttle pilots: Because the spaceshuttle is comperatively not very aeroydynamic, it has a 20° initial approach glideslope at 300knots and a decent rate of 10.000ft/min. To simulate that they train in a Gulfstream II jet with the gear extended and the engines in reverse.
Great Video always wanted to know that. By the way, I think your dog wants it's own TH-cam Channel.
I'm happy to hear that the safety checks for thrust reversers have gotten better! The FlightChannel produced an animated video on the Lauda air flight 004, and since then I haven't been able to not think about that accident while on a plane. I'm a long time fearful flyer, but it's not the turbulence that bothers me, it's all the minute details that could go wrong and set off a chain reaction in flight that could produce an accident. Like how on JAL 123 a cracked fan blade caused that entire thing. Thanks for explaining this!
Pilots error is the cause of most accidents not mechanical failure.
Sir, haven't they yet contacted you for teaching at a Flight Academy or so? Very seldom do someone get my attention and respect as you do. Very sharp thinking, so eloquent speaking. Best of luck in your pursuits, and may God keep you safe.
I like the clamshell thrust reversers! They’re cool looking!
Does reverse thrust in dry and hot conditions really not minimise the landing distance? In my undestanding of physics, its just one more force added to the others like spoilers and brakes to slow down the aircraft. I really think you will achieve the shortest landing distance with all forces combined, including reverse thrust, no matter if its dry and hot. But maybe I am wrong here. An answer would be super helpfull :D Great video as always :D
Flaps produce lift.......essential at slower speeds. Ground spoilers destroy lift, therefore gluing the aircraft to the ground.....again, they're essential and help to slow the aircraft down. I agree that with brakes, reverse thrust and ground spoilers combined you'd achieve the shortest landing distance
I had the same confusion, but I think he means there is no difference *for the same landing distance*. The thrusters add more force, so the brakes can work less to stop in the same distance.
Spoilers do very little to stop the airplane. You are right, it is the combined use of all braking systems that maximizes stopping power. That's why you'll notice, if you hang out at an airport and watch some landings, that the pilots use both brakes and thrusters to stop passenger planes.
There has been a number of runway over run accidents caused by pilots forgetting to set the spoilers
@@jameskoralewski296 The primary purpose of the ground spoilers is to maximise wheel brake efficiency by "spoiling" or dumping the lift generated by the wing and thus forcing the full weight of the aircraft onto the landing gear. The spoiler panels also help slow the aircraft by producing aerodynamic drag.
I remember we had 2 or 3 aborted takeoffs in a Sabena A310 out of Dakar around 1983. I was in the front seat in business class and saw the captain leaning out of the door and looking back at the port engine. I said hello and asked what was going on and he apologised for not getting us back to Brussels. he said he kept getting a reverse thrust warning light on one engine before V1. I laughingly said 'I like it here' let's just stay'. That is what happened, in fact as the crew were running out of hours and the engineers needed more time to be sure that the problem was a faulty indicator. One engine going into reverse would have been fatal. There was also a big gap between attempts in order to let the brakes cool.
Better to take a faulty light seriously, than to just conclude that all is fine.
A Lauda Boeing 767 crashed because the left engine's thrust reverser opened in mid-flight, it was Lauda Flight 004
Exactly the incident I was thinking of
Yea
He covered that towards the end.
Could shut it down... but you'd not know it was happening
Just love the dog. Makes it more interesting
3:17 loved the connection to cars. Honestly makes it much eaisier to understand.
He makes an excellent case for traveling by train.
Flying is safer than cars, buses and trains.
he just said that's its impossible to pull the handbrake mid flight .... but yeah, feel free to travel by train.
Yet trains aren't as safe as planes, you do you I guess 😂
I thought you said "Trust reverser", I immediately thought of my wife ;D
divorcee?
lol
Dude. Lots of us have been there. Those who haven't, they have no freaking idea.
Lol me too
Eternal Tech Me either! Can I ask what MGTOW is though... 🤔
Old fashioned "organic" (asbestos) brake linings were efficient when cold then as they heat up they become less efficient - "fade."
Full metallic brake linings on the other hand are inefficient when cold then as they heat up they become more efficient. For highway cars a compromise is made to balance between cold/hot by mixing metal "shavings" in the organic material - "semi-metallic" brake linings for more consistent brake performance.
That works for disc brakes but not for drum brakes. When heated the drums expand away from the shoes. It doesn't matter what the brake lining is of it isn't applying pressure to the opposite surface.
Another accident with thrust reversers deployed in flight (in fact, during takeoff) was the TAM flight 402 in 1996 in Brazil. The thrust reversers kept deploying contrary to pilot's will, which in turn led the aircraft into an asymmetric thrust that led it to a stall mid takeoff.
Love this channel.
Even though I know all of this, it’s nice to see someone teaching others about flying.
Thankyou.