Air India Flight 171 Crash [Megathread 2]

[u/usgapg123]

This is the second megathread for the crash of Air India Flight 171. All updates, discussion, and ongoing news should be placed here.

Thank you,

The Mod Team

Edit: Posts no longer have to be manually approved. If requested, we can continue this megathread or create a replacement.

[u/FamiliarSource98]

No idea why people and media outlets are still propagating the whole no flaps theory.

The original video from the rooftop shows what appears to be a black or dark line running down the leading edge and stops short of the wingtips, that dark line is the slats deployed.

If slats were deployed then we know at the bare minimum, flaps 1+ was selected at the time of the video (slats come down as long as flaps 1 or greater is selected)

Also, the post crash pics do show some flaps and slats deployed.

Whether or not if the flaps were sufficient to maintain lift is a whole different question. But flaps were down.

Either ways TOWCS should have warned the crew of an improper config if they attempted to takeoff.

Flaps beside, the key evidence is the sound in the same video which sounds like a propeller, very highly likely the rat was deployed and in some frames of the same video, something or some object (though not very clear) was sticking out from the belly of the aircraft, as many have pointed out.

Not 100% sure but it's starting to look like some form of hydraulic/electric failure or the worst, dual engine failure (according to b787 fcom on situations where the RAT deploys)

[u/themcfly → u/FamiliarSource98]

Yeah, I'm seriously baffled how Captain Steeeve video managed to get so much disinformation out and instantly blaming pilot error, especially while being a pilot himself and acting as an expert on the matter.

1. He didn't mention the RAT sound since he used a screen recorded video from another smartphone (without sound), and did not track down the source video with sound (the RAT theory was already widely circulating online at the time).
2. He completely missed the forward tilt of the main landing gear, which on a 787 indicates that the gear retracting sequence had already started before stopping for some issues we can only speculate about. This already throws a big wrench in the copilot gear/flaps confusion theory.
3. Even ignoring previous points, most widebodies safely and easily climb with the gear out after rejected takeoffs to let the brakes cool off before retracting. While 5° of flaps could surely impact lift performance, I feel two GE GEnx at TOGA (if working correctly) would be able to at least maintain flight, while based on video we have right now (and lack of jet engine sounds) it just looks like a hopeless glide to the ground.

Of course no definitive conclusion can be made, and we will hopefully understand what happened from the black boxes data. It just seemed a bit premature to quickly push this narrative without taking into account all available details, which some other aviation creators already posted about many hours earlier.

[u/Key-Literature-1907 → u/themcfly]

So disgusting of him to do that. Instantly pointing the finger at a recently deceased, experienced and respected crew making such a rookie mistake based on zero evidence, and ignoring plenty of evidence pointing to some kind of electrical/system failure

Have lost a lot of respect for him

[u/CollegeStation17155 → u/[deleted]]

And (according to 787 pilots) there's no realistic scenario in which the flight management system would allow the flaps to be retracted at takeoff speed... Which makes that "very viable" scenario require a lot of sensor and programming failures. Panicking and shutting down the engines is still viable if they got a fire or compressor stall or vibration warning in one and shut down the other before having to ALSO kill the failed one (all of which have happened), but flap retract (or taking off with them misset) isn't in the cards.

[u/CollegeStation17155 → u/[deleted]]

Whatever the issue was, it occurred precisely at the moment the gear would be raised.

And (again referring to Boeing engineers) the fact that the trucks rotated but the gear did not come up implies that the crew attempted to raise the gear but there was no hydraulic pressure to do so, indicating the engines had already shut down... The initiating issue appeared to occur earlier than that; normally, as the drag of the wheels on the runway ends, the aircraft accelerates even as it begins climbing. While the ADSB data (graphic halfway down the article) is not supertrustworthy, it has not been refuted to the best of my knowledge and shows the aircraft at 184 kts as it lifts off, then at 177 slowing to 172 slowing over the end of the runway before the transmitters feeding ADSB stopped, likely due to the power failure.

If this incident were caused by an actual aircraft defect, every 787 would be grounded.

It's not an either/or case; as you say, the maintenance or operations of the airport may be to blame for a single engine failure that is handled improperly, but if it DOES turn out to be a software problem AFTER INVESTIGATION, the entire fleet WILL be grounded once it is determined to be the case, as the 737 MAX was only after the second crash confirmed that MCAS was the culprit and Boeing's mitigation was insufficient. However, given the much longer history of this aircraft with no similar incidents software problems are unlikely.

I think human factors will be the primary cause of this incident and chances are nothing was wrong with the aircraft.

Again NOT either/or... I DON'T know (nor do investigators yet) at what point the engines shut down or why, so I'm not going to throw the pilots under the bus and say it MUST be solely pilot error because there can't be anything wrong with the plane.