Air India Flight AI171 Boeing 787 Dreamliner Crash - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: June 12, 2025, 10:42:04 am
content: A tragic crash just happened immediately after takeoff.The first crash of Boeing 787 Dreamliner.242 on board.https://x.com/flightradar24/status/1933086087682904336Crash footage:https://x.com/i/status/1933096539192238159https://www.bbc.com/news/live/c8d1r3m8z92t

author: tom66
author_rank: Super Contributor
timestamp: June 12, 2025, 11:00:44 am
content: Oh no. And it looks like it hit a hospital when it came down. For such a plane to crash so quickly after taking off there are not many possible faults. Double engine fault due to bird strike or runway contamination perhaps. Tragic.

author: TERRA Operative
author_rank: Super Contributor
timestamp: June 12, 2025, 11:01:44 am
content: I saw talk of flaps possibly not being engaged leading to a stall.I have no idea about plane stuff, so I can't make any educated comments on the mechanics of what happened.

author: jpanhalt
author_rank: Super Contributor
timestamp: June 12, 2025, 11:09:26 am
content: That is strange. I had to read it and watch the video several times. The crash apparently occurred during or after takeoff, yet the video looked like an approach and flaring too high or attempted go around , then drop/stall. Engine failure(s) like the Hudson river crash several years ago?

author: EEVblog
author_rank: Unknown
timestamp: June 12, 2025, 11:46:37 am
content: Quote from: TERRA Operative on June 12, 2025, 11:01:44 amThat seems to be the going consensus on X at the moment. But as always at this point

author: EEVblog
author_rank: Unknown
timestamp: June 12, 2025, 11:49:26 am
content: Quote from: jpanhalt on June 12, 2025, 11:09:26 amSeems like direct takeoff, but the ADS-B might not be updated that quickly to show a last minute turn.But I think the hospital it crashed into is directly inline with the runway.

author: EEVblog
author_rank: Unknown
timestamp: June 12, 2025, 11:55:51 am
content: Found the crash site map on X, correlates with where I was looking at too.https://x.com/FinanceLancelot/status/1933093997448491181

author: tom66
author_rank: Super Contributor
timestamp: June 12, 2025, 11:57:55 am
content: Quote from: TERRA Operative on June 12, 2025, 11:01:44 amThis would surely lead to a configuration alarm (flaps in wrong configuration for flight) but it's possible that in the moment this got lost as pilots focus on maintaining altitude not realising the situation they are in.

author: jpanhalt
author_rank: Super Contributor
timestamp: June 12, 2025, 12:35:19 pm
content: T.O. Flaps are typically set before the TO roll begins. I don't know about that level of aircraft, but if flaps are not properly set, and there a warning for that, it should have occurred when TO power was applied. Surely, someone has a picture of the TO, and of course, it will be in the flight data recorder when that is analyzed.

author: TERRA Operative
author_rank: Super Contributor
timestamp: June 12, 2025, 01:02:46 pm
content: Yeah, I was wondering about alarms even before takeoff if the flaps weren't engaged.The black box data will hopefully reveal what went wrong..

author: tom66
author_rank: Super Contributor
timestamp: June 12, 2025, 01:34:31 pm
content: Can't rule out crew tiredness or crew resource management issue... many times captain has done something wrong and FO doesn't want to overrule feeling that they are not senior enough. Some airlines are very careful about CRM but others less so.

author: tggzzz
author_rank: Super Contributor
timestamp: June 12, 2025, 02:15:35 pm
content: If you want to try toguesswhat position the flaps and spoilers were in, you can look at the flight immediately before and during the crash... Before making my guess, I'd like to see what the flaps look like in a normal takeoff.(It might be the same footage as on twatter; I wouldn't know)

author: asmi
author_rank: Super Contributor
timestamp: June 12, 2025, 02:51:31 pm
content: Quote from: tom66 on June 12, 2025, 01:34:31 pmThis is a long haul flight, so crew must be fresh from home.

author: asmi
author_rank: Super Contributor
timestamp: June 12, 2025, 03:00:41 pm
content: Quote from: jpanhalt on June 12, 2025, 12:35:19 pmIt's not just a warning, but entire takeoff profile (V1, V2, Vr speeds) is calculated by the onboard computer depending on the flaps setting. If pilot attempts to rotate plane at Vr calculated for engaged flaps while actually having flaps all the way up, it would simply not lift off at all and will crash beyond the end of the runway - unless it somehow manages to accelerate fast enough for "clean" take off. Though I'm not even sure these large planes can take off in "clean" configuration - maybe when they are close to empty, but not while being fully loaded likely above max landing weight (which is normal for long haul as by the time they reach their destination they will burn enough fuel to be under that limit).The only flaps-related issue I can think of could be that they accidentally raised flaps higher than intended, and lost lift - because that flare up in the video does look like an attempt to get more lift by increasing angle of attack.

author: asmi
author_rank: Super Contributor
timestamp: June 12, 2025, 03:08:44 pm
content: Oh, and something I should have started with - RIP to deceased, my sympathies to their friends and families.

author: tom66
author_rank: Super Contributor
timestamp: June 12, 2025, 03:59:05 pm
content: Quote from: asmi on June 12, 2025, 02:51:31 pmDoes not mean they got enough sleep the night before. Some airlines really wreck their crew flight schedule. For instance, same crew might have landed 10pm from a similar London flight, then depart again at 1pm the next day. If their day-night cycle doesn't sync well, they could get really rough sleep and not be as attentive during critical phases of flight.This was considered to be one of the contributing factors to the Asiana disaster at SFO.

author: bdunham7
author_rank: Super Contributor
timestamp: June 12, 2025, 04:10:29 pm
content: There's been a lot of speculation based on spotty preliminary information, but if we all just wait a bit I'm pretty sure we're going to get a lot more usable evidence pretty soon. The FDR and CVR will be in good shape and we'll get clarity on a lot of the other things that have been claimed. Initially there were claims that they did an intersection takeoff and didn't use the whole runway, now it appears those were based on spotty ADS-B data. There are claims that the flaps were up, that they were put up mistakenly, etc and the available videos don't really support that AFAIK. So just hang on--I doubt that this will end up as a mystery like the unfortunate recent 737 crash in Korea. The leading theories are 1) egregious pilot error 2) dual engine failure or 3) something else not obvious at this point. I'm leaning towards #3.

author: SiliconWizard
author_rank: Super Contributor
timestamp: June 12, 2025, 04:23:11 pm
content: The plane appears to have no flaps on the videos, which is definitely NOT normal.Was there an engine failure on top of that, aggravating the loss of lift?The only thing we can see for sure is no flaps, not even a notch, right after takeoff with the landing gear still down. That doesn't make sense.The investigation will tell why and if there were associated issues such as engine failure. At this point, I don't think we can say anything more than this.

author: LaserSteve
author_rank: Super Contributor
timestamp: June 12, 2025, 04:24:27 pm
content: RIP to all on board, and hope and prayers for the familes in this time of great loss.Here are some of the alarm tones.https://youtu.be/KJfP9bzSYx0https://youtu.be/RJUWAt2Q5LEhttps://youtu.be/7vexEOygCeEVisual and Aural warnings training video:https://youtu.be/pELSdEqo0HwFor stall there would be a stick shaker on the yoke.Steve

author: krish2487
author_rank: Frequent Contributor
timestamp: June 12, 2025, 04:28:08 pm
content: I m told that its not just the passengers on board that were casualties. The plane crashed in a populated area on some buildings. I m told that there are several tens of casualties from the crash impact as well. But again, we will probably know more after a few more hours.

author: BadeBhaiya
author_rank: Regular Contributor
timestamp: June 12, 2025, 04:34:26 pm
content: The plane crashed into a medical college hostel. Casualties are mostly medical students

author: bdunham7
author_rank: Super Contributor
timestamp: June 12, 2025, 04:47:59 pm
content: Quote from: asmi on June 12, 2025, 03:00:41 pmYou can rotate into ground effect but then either not be able to climb out of ground effect or experience increased drag and loss of energy when you do. If you are aware of a low energy problem you can use ground effect to accelerate and escape your predicament, but normal SOP is to climb sharply to about 400' before nosing down to accelerate. A twin-engine passenger jet typically has a lot of excess thrust available if everything is working so the standard reponse to low energy situations like wind shear or early rotation is to apply full power and maintain a nose-up pitch, essentially blasting your way out of trouble.

author: bdunham7
author_rank: Super Contributor
timestamp: June 12, 2025, 04:51:47 pm
content: Quote from: SiliconWizard on June 12, 2025, 04:23:11 pmI can't see that and whatever we see it isn't for sure. There's some disagreement among those with more expertise, but most agree that you can't tell that there are zero flaps there. Perhaps not a lot of flaps (1-5?) but you wouldn't necessarily expect a lot.

author: m98
author_rank: Frequent Contributor
timestamp: June 12, 2025, 05:04:49 pm
content: They might have retracted the flaps to increase gliding range after engine failure.

author: bdunham7
author_rank: Super Contributor
timestamp: June 12, 2025, 05:41:28 pm
content: Quote from: m98 on June 12, 2025, 05:04:49 pmIf they had a LOT of flaps set, as in a landing configuration, then retracting them to a lesser flaps setting might stretch the glide. See BA 38 at Heathrow. However in this case the flaps would have only been out a small amount and since I think it has been stated that their maximum speed was 174 knots--well below their minimum clean speed which I believe would be over 200kn--retracting flaps would have shed too much lift. They wouldn't have done that on purpose.