An Air India Boeing 787-8 Dreamliner operating as Flight AI171 from Ahmedabad to London’s Gatwick Airport crashed shortly after takeoff on Thursday. Out of 242 on board, only one survived. Now the question on everyone’s mind is: what exactly happened?
Veteran Indian Air Force (IAF) pilot and aviation expert Captain Ehsan Khalid spoke to NDTV to decode the anatomy of one of the deadliest crashes in India’s aviation history.
Q: There are two videos that we have of the crash. A 36-second video that’s been taken from somebody’s window. You can see the aircraft descending into the neighbourhood there. And a 59-second video which captures the entire sequence from takeoff to landing. What are your opening comments?
Captain Khalid: The only thing conclusive that I can see is that the landing gear has been down throughout, and landing gear is something that should have been taken up in almost all kinds of scenarios that a pilot gets in the aircraft, except when there is wind shear and the aircraft is committed to continue to descend. So we keep the landing gear down consciously.
Q: But we counted the time taken from the time the aircraft lifts off till the time it impacts the ground. It’s just 32 seconds.
Captain Khalid: That is the amount of time it will take to rotate the aircraft to go up. 825 feet is the wrong height, 625 feet is the wrong height. It would not have gone higher than 200 to 250 feet. So the aircraft, when it is taking off, it gets airborne, selects the landing gear up, and keeps the flap. Flaps are lift augmentation devices that allow the aircraft to continue climbing at lower speeds while it is accelerating. So the aircraft gets out of the ground effect. Ground effect, meaning, you know, there is a cushion of air between the wing and the ground. It adds to the lift, reduces the drag. So even if the aircraft speed is low, power is low, it will be able to get out to something like 100 to 150 feet out of the ground effect. Now the aircraft does not have the ground effect. There is a loss of power, or the speed is low.
Q: At this point in time, you can see the aircraft instead of continuing to ascend, it seems to level out and then it starts to descend.
Captain Khalid: One thing that can be ruled out is that there was no control jam. Control jam means the aircraft pilot moves the control, but it cannot move. It can happen. It does not happen in this case because in one of the videos, you will see the aircraft continuing to pitch up. So that is one of the indications that the aircraft was actively being flown by the pilot.
Q: The flaps are another point that has come up for a lot of debate. Let’s just talk for a moment about this image. It’s a very grainy image, and there are many experts who say you cannot tell one way or the other about the takeoff configuration. Does this look like a takeoff configuration to you?
Captain Khalid: No way. I’ve also tried to zoom it. You cannot say. You cannot make out that the aircraft is having a configuration problem here. Let’s assume that the flap is not in the right place, then the system has so much automation, it will shout at you, “Flaps.”
Q: It will not take off in a wrong configuration, then?
Captain Khalid: It is like somebody shouting at you, “Wrong configuration, wrong configuration.” You can’t take off. So that thing is ruled out. Aircraft has gone up. The flaps, let’s assume, not assume, I’m pretty certain that the flap is to the configuration. This aircraft, and many modern aircraft, in fact, all modern aircraft, have got flap auto-retraction mechanisms, and that gets signals from airspeed. It gets signals from the electrical system and sensors.
Q: What do you think happened? You know, these are early hours. I understand that. But what is your best guess?
Captain Khalid: I will tell you the most probable thing. Looking at the airfield like Ahmedabad, There were a lot of birds. That would cause distraction. But it will cause a loss of power, a loss of the indication system, loss of the airspeed system. That will now create a situation which is totally out of the book for the pilot. So what the pilot did at that point in time is not in the book. It will also preclude the landing gear from going up. It can also cause, without any interference from the pilot, flaps to go up. So let me tell you that Boeing 787 aircraft, having flown 30 million hours, has not had any of this wrong flap retraction. So in the field of speculation, we can speculate a lot, but certainly, the pilot was actively trying to control the aircraft, and they gave a Mayday” call. That means they were seeing something which is visually telling them that things are not right. We’ll know about that once the black box is analysed.
Q: So there is no way of telling from just this crash video or these still images whether the flaps played some kind of a role. That’s what you’re saying?
Captain Khalid: Absolutey. From here you can’t conclude. But the fact remains that the aircraft did not do a successful flight. There was a loss of lift. Loss of lift can happen because of loss of airspeed.
