On en sait plus sur le crash Air India 171 : DOUBLE panne moteur ?

Good morning, my friends. We know a little more about the Air India 787 that crashed two days ago in Ahmedabad. So there is some information that corroborates a theory that I put forward yesterday. And then, of course, there are two or three things that I was able to find that I will share with you. So first, the media has all gone for the flaps story. That means the media assumes that the flaps were not deployed during the takeoff roll. See alternative theories that the pilots got wet and retracted the flaps instead of retracting the landing gear. This theory is highly debatable. And even if it has its hypotheses, it has its merits. Well, it seems quite unlikely to me at this stage. First, people say you can't see the flaps in the videos during takeoff. Indeed, you can't see the flaps. But there's one thing you need to know. The 787 is a very modern plane with flaps that are much smaller than the old Boeings. If you look at the old Boeings, you'll see that the flaps look like barn doors. Literally, they're big barn doors that are placed one on top of the other, you know, that generally fit together. And then there are endless engine cranks with big screws that turn. And then they push the flaps outward so they not only deploy, increasing the wing surface, but also go down, increasing its curvature. You can see those. You can see them from very, very far away. That's not the case on the 787 because it took off a bit like a Cessna 152. It's just the trailing edge of the wing, the rear part of the wing that does that, that's going to lower. Look at that. It's the rear part of the wing that makes that tick. You see, you just have this part there that lowers, so there's nothing coming out and all that. So the device is pretty hard to see. By the way, I'm going to show you two videos. You're going to see 787s taking off from a distance, and I challenge you to guess whether the ones took off or not. Of course they did in these videos, but it's not something you can see or appreciate by eye. So that's the first point. Secondly, if we look, there is a very particular kinematics on the landing gear of the 787. That is to say that when the plane lands, there are four wheels per bogie. So it has two main landing gears. We're not talking about the nose gear. There are two main landing Gears, each with four wheels that are placed two by two, a bit like the, I don't know if we say beautiful on a semi trailer. In fact, four wheels like this. And in fact, they are positioned so that the rear wheels, the two rear wheels touch the ground first. So the plane arrives, the two rear wheels there, they touch down before, and then the bogey flattens. Okay, takeoff, how does that happen? Then during takeoff, it happens like this. You see a 787 accelerated. It takes off. The front wheels leave the ground first. The rear wheels follow. Right? That's the bogie, Right? Front wheel, rear wheel. And what happens when the pilots select the little one? They have a little lever there on the dashboard. They put it on the landing gear, retract. There's a hydraulic cylinder that does this to the bogie. Why? Because if it goes like this to retract, it will never go back into its housing. So it will align it with its housing. And this gives a very characteristic movement on the 787 that we don't see with other planes. It does this. The bogie does this like this. It goes horizontal and then starts to retract. I'm going to show you that. I'm going to show you a little bit on YouTube. I found a plane taking off. I'm going to zoom in on it and I'd like to invite you to watch. I would like to invite you to observe what the landing gear does. And you will notice that suddenly we see the bogey moving forward. And in fact, this corresponds to the moment when one of the pilots, the one who is monitoring the pilot, retracts the landing gear. This is the first thing that happens on the Air India. If we look at an enlargement of the video, we will see that the landing gear is horizontal. The bogies are in a horizontal state. That means that this action took place. That means that the guys had started this movement. And of course, afterwards they no longer had hydraulics to keep the landing gear retracting. What we probably have in this situation, we have our Boeing 787, which is flying with the landing gear down, the landing gear lever in the raised position, and probably somewhere there are shadow lights indicating that the landing gear is in transit. Okay, so this is a situation I think that in my opinion, of course, we will see with the investigation and everything excludes the fact that the pilots feel they made a mistake. So a takeoff with the flaps retracted is practically impossible on a 787. As I told you, there is the electronic checklist. There is also the story of the alarm configuration, which means that it is not like a spanner. For example, look at the spanner, right, which was an MD80. I think it was roughly spanner5 011 he which killed nearly 150 people in Spain. He had taken off with the flaps. He had tried to take off without the flaps. He never left the ground. In fact, when you're in an airplane, and especially a Boeing, even if you Hear it on Arbus 2, when you're on a Boeing, sometimes when the plane is heavy and takes off, you're sitting close to the wings. You literally hear the wings hanging like that. You hear a vibration at the moment of takeoff. When the plane pitches up, the wings are hanging in the air at that moment. If the leading edge slats, I'm not talking about the flaps at the back, they're less important. But if I take the leading edge slats, if they're not extended at that moment, the stall is guaranteed at that stage. Especially on Boeings. Why? Because Boeings fly faster, need to fly faster than Airbuses. All things being equal, you Compare a triple seven, for example, and you compare it to an Airbus 380. The Airbus 380 on an approach flies much slower than a Boeing 77 or a Boeing 787. Airbuses. An Airbus 330 behind one that is in front of a 787 poses problems for air traffic controllers because Boeings are generally these big Boeings that are classified as category D. They have higher approach speeds than Airbuses, which are category C. That means that the speed margins relative to stall are much wider, lets say on Airbuses than on Boeings. That means Boeings. Again, I'm not suggesting that an Airbus can take off with its slots retracted. I'm not suggesting that probably, if it tries, it will probably crash just as easily as a Boeing. But what I'm saying is that a Boeing has much less aerodynamic margin by choice. There's nothing in what I'm saying that suggests that one choice is better than the other. I'm simply saying that aerodynamically Bowens fly faster. That's a technological choice. There's no good or bad thing about it. It's just a choice that differentiates these two types of aircraft. Okay. All that to tell you I'm excluding this whole slat and flap thing. I don't believe it at all. But we'll see when the final report comes out. Now, the video I showed you yesterday, the video where you see guys talking, the plane moving away, all that I told you that at the beginning of it, you could hear a noise like a propeller. You could just hear a very fast tap, tap. Today, good news. The original high quality video has been released. That means we can now see and hear better. I would like you to hear the noise this plane makes. When you hear this noise, you realize that it makes the same noise as a club plane. Literally, it sounds like a propeller. This is probably what is called the rat or turbine ram. On the 787, there is a turbine that is placed towards the rear, a little towards the main rear landing gear. And in fact what it does is that when there is a loss of electricity or loss of engine in certain situations, what it will do is it will extend by itself. It can be extended manually, but there are situations where it extends by itself. It actually has a sort of alternator, a propeller. And with the relative wind, this alternator will provide electricity to the plane. So if it comes out, we can imagine that we are in a situation where both engines are stopped. We saw the spleen the last time we talked about it on this channel. It was when this Pakistani plane, an Airbus A320, crashed. Do you remember when it crashed with both engines? Well, it crashed with both engines because it tried to land without landing gear. I told you about it when it was a news story, but I never got around to talking about it. Maybe I should make a retrospective video on that. And in fact, what happened is that both engines crashed. So they finally stopped. And at one point we see the spleen that had come out. It means to provide more energy to this plane by using the force of the relative air. This spleen makes a particular noise that we hear in the case of the Indiana area. So we are roughly moving towards a situation of two engines shut down, aren't we? Which is quite consistent with the trajectory that we are seeing. And the flaps do not seem to be a factor in this statistic. So we also have something else. We have the testimony of the survivor, a survivor who was seated in seat 11A and miraculously survived. The media probably mistranslated it when they said that he jumped out of the plane. In fact, he did not jump out of the plane while it was in flight. It is likely that there was an impact and then he jumped to get away from the fire and all that. That is probably what he meant. Some media have even tried to corroborate this by showing an object that appears to have fallen from the plane and saying, look, he probably opened an emergency exit to jump out, which seems Unlikely for a passenger to release their seatbelt and open an emergency exit with positive pressurization. You should know that. I'm not 100% sure. I don't have all the documentation, but there's a lot about the 787. But often when airliners take off, there's a slight overpressure inside. You can feel it in your ears, which allows the doors to press against their seal. And so, technically speaking, if someone were to stand up and try to open an emergency exit while the plane is in this configuration, I doubt they'd be able to open it just like that. And what's more, the media shows what they call the door falling, but they don't show the passenger jumping out. So really, it's an extremely crazy idea. This object that we see jumping, this object is probably when there is an air accident, there is something that sometimes jumps, bounces violently against the ground and can go very high. It is the landing gear. Since these are tires filled with nitrogen, well, they can quite brutally hit the ground. If they do not explode, if they do not burst at that moment, they will tear and, well, they will bounce, bounce quite high and fall. So we see two landing gears. We see both. There's one that got embedded in the building, so that one stayed there. And there's another one that seems to be a little bit in the open air. And it is this one, probably, that bounced in the images that were very widely shared and wrongly by the media. Another thing, the passenger who survived, what did he say? He said the light went out, it came back on. The light went out, and the green light, and so on. Okay, this testimony is very interesting. This testimony is very interesting. And if we try to corroborate what happened, here's a little bit of what we can understand. The plane lines up on the Runway to take off, puts on the throttle, starts to accelerate, passes the decision speed v1. And so what happens is that now the pilot takes his hand off the throttles, he has to take off no matter what. At that point, we have an engine failure at some point. Why? We'll see. Maybe he hit some birds. Even if we didn't see any, maybe something happened. Poor maintenance, Something happened, by the way, we just pass between us, just between us. In the last few days, there was an alert on one of the engines on this plane, there was an alert that gave rise to some concerns, but it was verified, validated and everything. But on one of the engines, there was an alert. I can't tell you more. You won't see it anywhere. It came from here, it came from this channel. It came from me. But there were concerns. One of the engines gave rise to concerns on this plane. So one of the engines, but as long as it had been giving rise to concerns for some time, it failed. Okay. The plane continues to accelerate, pitches up, and lifts off the ground. When the engine fails, the pooh. You should know that the poo of the 787 has an auto start position. If an engine fails, it can start on its own, so be careful. When the engine is lost, the POO will engage its autostart cycle. But it can easily take 15 seconds plus a few seconds before the generators ramp up and are able to deliver power. But let's say that at that point, the APU will trigger the light in the cabin. We're trying to corroborate the passenger's story. The light in the cabin is normal. If an engine fails, the light won't change. The plane won't lurch suddenly if an engine fails. Because some have said, yeah, but I see a slight crab on takeoff, but I don't see it make a sharp movement and so on. The movement won't be that sharp. The reason is that it has the ability to correct itself, the asymmetry caused by an engine failure. So it corrects it in such a nice smooth way that you won't see anything abrupt, as if a human pilot had corrected it. So it practically corrects almost all of the asymmetry of the takeoff. Right. It will correct it all by itself. It is a very, very modern, very sophisticated aircraft. So that's why you won't see anything spectacular in the event of an engine failure. So I'll add that our aircraft starts to climb at that moment. The pilots necessarily take a positive vario. So what do they do? First action after takeoff. Positive vario. The landing gear lever clicks. Starts to retract the landing gear. The sequence begins. The landing gear. The main bogey makes a click like that, it goes horizontal. Right? The tilt is canceled by a small jack. At that moment, the second engine stops. Why does it stop? I don't know. Same reason as the first. It ate birds. It was stopped by mistake by a pilot who reacted by thinking slap. Huh? It can happen. Huh? Remember the Concorde? Huh? The Concorde, which did almost the same thing as the Concorde, did the same thing, the same trajectory as this plane. Ha. Ah. Two Takeoff. No engine during takeoff. It climbs. It wants to go to the airport. It can't do it and it falls. It stalls during acceleration. During Takeoff, there is an engine that was already manually stopped. Do you know what I mean? So sometimes we can have reactions that are a little quick, untimely, and unfortunately that can be wrong. That can be wrong. So was it a human who stopped it? Yes. Why not? Why not? In any case, it doesn't matter what the reason is. Once the second engine stops, what will happen is that the light goes out. So several things will happen very quickly. The light in the cabin goes out and immediately a light comes on with green aisles and everything. It's the emergency exit light. This one has absolute priority and so it's going to work on the aircraft's batteries. So what does the passenger see? He sees the light go out and the emergency exits are displayed immediately. In the meantime, the glider is going to pop out. The dashboard on the co pilot's side goes out. This is because the glider is very minimalist in the electrical current it provides. There's not enough to power everything, especially since life doesn't move very quickly. So choices have to be made. The landing gear won't continue to climb. We agree on this. Because the spleen, even if it supplies electrical current, can power electric pumps, hydraulic pumps, and that's the purpose of the entire spleen. It will be more for the controls. Right. I know that on most planes retracting the landing gear in the configuration of the hydraulic circuit, retracting the landing gear is not a priority. And honestly I haven't looked at the documentation properly yet, but I'd bet my life that it's the same on the 787. I can't see a 787 flying slowly on a spleen. I can't see energy being used to retract the landing gear. I don't think that's possible. But if someone comes to correct me in the comments, well, that's not a big deal. So I was saying at that point, uh, the pilots send my okay, they say they've lost power, they send my. The plane starts to come back towards the ground in a nose up position. It's slowly coming back towards the ground. We're talking about less than 500ft per minute. Right. And so what's going to happen is that at some point the poo arrives. That means the APAPU finishes its ignition cycle, auto ignition, and it arrives. When it arrives, the, the lights come back on in the cabin. So inside the cabin the lights come back on completely. So there in relation to the passenger, he sees the lights go off, come back off. That's kind of the Effect it has in the cockpit. We have the dashboard of the copy there, which is starting to come back to life a little. We most certainly have the GPWS which is yelling in five. In five, huh? Loss of altitude just after takeoff, loss of height after takeoff. So generally this type of alert is generated so the pilots know that they are diving, descending, right? And, and at that moment, of course, we will approach the impact. We will approach the impact with the building that houses the medical students. And then, well, here is the rest of the story. The rest of the story, we know it. This passenger who somehow manages to eject, then he runs for his life, all of this. So, uh, so there you have it, my friends. It is, it is a huge tragedy because here we count about 280 dead, roughly speaking, counting those who were on the plane, 242 minus one who survived. So 2, 4, 1 plus there are about 50 people who died on the ground. But as time goes on, it's a balance sheet because as they clear the rubble and all that, several buildings have burned in this area. So as time goes on, they're going to establish things with more precision. So there you have it, my friends. That's the story of the 787. We'll see later when the black boxes have been analyzed. They were found, by the way. When they've been analyzed, I'll give you more details and all that. So to finish, I would like to thank, of course, all the flight crew, all the air traffic controllers, the professionals who throughout the world, across airlines, plains countries, follow this channel and then provide a lot of information, documentation, share their analyses, their experiences, and without them, this channel could never have existed. Thank you. Thank you to them regarding my consulting schedule, consult me for personal and professional stories and so on. There are dates and I'll put the link in the video description and the pinned comment. Thanks for watching this video so far and we'll be back in the next one.