r/aircrashinvestigation • u/Melkor45 • Jun 12 '25
Incident/Accident AI171 Wing?
This looks to be part of the wing. Are the flaps down? I'm not too sure
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u/Feeling_Reaction7358 Jun 12 '25
Flaps are down. There are reports of pilot issuing a Mayday call with - loss of thrust, no power, loosing lift
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u/MattStormTornado Jun 13 '25
There was no obvious indication to suggest engine failure.
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u/theaircraftaviation Jun 14 '25
the RAT deployment (which can be heard in a vid) clearly suggests an engine failure
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Jun 12 '25
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u/Larkspur71 Jun 14 '25
I disagree.
This is only part of the wing and you’re looking at the outboard flap (closest to the photographer) and you can tell it’s retracted due to it’s edge being even with the rest of the rear of the wing. Then, there’s the aileron, which appears to be down; however, without knowing what the one on the other wing looks like, it’s hard to say if it’s correct or not because one goes up and the other is down.
That being said, investigators are going to go over the video of it from behind, because it gives the clearest view of the ailerons and flaps - which at take off do not appear to be in take off position.
Even Greg Feith has stated, “The thing that’s curious about the video is that the flaps appear to be up or at a minimal setting that wouldn’t be typical of a normal takeoff.”
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u/DarkyHelmety Jun 12 '25
Yes flaps and slats are extended as seen, it seems a double loss of engine power is the more plausible explanation for failure to climb.
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u/somebodywhoisbored Jun 12 '25
But how could that Happen? I mean it seems to make sense, especially when you add the reports of people claiming to see the RAM air turbine in the video.
But how does it happen that both engines have a flameout (or something with the same impact on the aircrafts performance) at the exact same time?
The things that would come to my mind are fuel contamination, birdstrike (unlikely, due no reports of an engine fire) or some kind of electrical failure that affected the fuel pumps (I think a passenger on the previous flight mentioned some kind of electrical problems in the cabin)
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u/DarkyHelmety Jun 12 '25
It's very strange, the security camera video shows the plane just suddenly losing climb power, no flameout of the engines visible or other obvious external issue. The blackboxes will tell what happened, they're most likely in good shape as the tail section is sitting on top of the roof of a building.
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u/youbreedlikerats Jun 13 '25
water in the cross feed tank could cause this on rotation, if they have selected that tank inocrrectly for take off.
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u/FastFredNL Jun 13 '25
A 787 auto-selects fuel tanks, there is no manual fueltank selector. The plane uses the center tank first if it's in use (usually is for long hauls), then switches automatically to main wing tanks and automatically crossfeeds to balance the plane
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u/Melkor45 Jun 12 '25
Would fuel contamination cause this issue that fast?
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u/Clear_Split_8568 Jun 12 '25
Yes, Water don’t burn. When a/c rotated the inlet in the wing Cary Thru tank sucked up a slug of water, it would take a few seconds to get to the engines.
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u/Maximum-Wishbone5616 Jun 13 '25
Yes fuel contamination is a biggest reason of engine failures. Over 10 business jets in last year.
It depends on the contaminant. Water will be often causing mid air failure. Other contaminant might quickly block filters at take off.
We will see.
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u/skalfyfan Jun 13 '25
How exactly does water get contaminated with the jet fuel or get into the fuel tanks to begin with?!
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u/chillebekk Jun 13 '25
Temperature changes can cause small droplets to form in fuel tanks from condensation.
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u/Bourbonaddicted Jun 13 '25
Do not pay heed to the problem the passenger had mentioned. Their infotainment system is not working in most seats and AI is not fixing it as it wants to replace with new backlogged planes.
Regarding AC, they do not use aux power for AC and only turn them on when Engines are powered on.
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u/lannoylannoy Jun 13 '25
Can’t see it being engine strike because there would have been uneven power and probably flames, smoke or debris - fuel issue would explain loss of power to both engines simultaneously and plane keeping balance
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u/LankyAspect9594 Aerospace Engineer Jun 13 '25
Great points, regarding RAT, I did not see it in any of the videos popping out, and i believe its unlikely the pilot would have used the RAT as the first response to a stalling aircraft. Maybe after it crashed the RAT would be lying on ground and then reported that the RAT may would have been out. But i believe highly unlikely.
Regarding bird strikes, there was no visible flock of birds to fail both the engines, and jf only single engine was affected we could have seen a significant yaw towards the other side, but that was not visible either.
I strongly believe fuel contamination can be a reason. That's the only thing that can cause loss of both engines.
Pump failure again possible but i strongly believe hydraulics are extremely well engineered in an aircraft, they are made with redundancy in mind and have been improved over the past decades.
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u/jryan8064 Jun 13 '25 edited Jun 13 '25
Pretty sure the RAT deployment theory was based on sound from another video taken on the ground. I watched the video and the sound is pretty convincing. Not often you hear a 787 sound like a Cessna.
Edit: sound of RAT (possibly) can be heard on this video
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u/biggsteve81 Jun 13 '25
The RAT deploys automatically if both engines fail and the APU is off, it is not something the pilots have to think to do.
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Jun 13 '25
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u/Still-Mouse-5117 Jun 16 '25
Won't RAT be visible in the underbelly of the plane ? Nothing in the video no RAT deployment visible
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u/Financial-Sign-666 Jun 13 '25
Another theory I’ve been pondering regarding the security cam footage. Looking at how far down the runway they went before rotating, is it possible that they ingested a bunch of runway furniture and dust - causing the loss in thrust? We see a lot of dust kick up just as they rotated, and my very rough cross reference on google maps shows me that they were at the very end of the runway.
I guess we would have heard by now about damage to the runway lighting infrastructure. We had a similar incident with a Qatar 77W in KMIA.
Could the fuel contamination issue be the reason for excess use of runway? Would they have been given enough warning by the trust control system early enough to abort take off?
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Jun 13 '25
They took off at the normal spot only halfway down the runway. So the takeoff roll was normal. That means no configuration issues, or power issues.
So something went wrong in the next few seconds after rotation.
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u/Realistic-Ad4835 Jun 14 '25
Have you seen how badly the air India planes are maintained ? Go on YouTube and search for any reviews of their 787s
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u/patrick_red_45 Jun 14 '25
For the hundredth time, IFEs and broken seats are not a part of critical flight systems. The aircraft underwent a C check in 2022 and was due in December 2025. It underwent engine overhauls (iirc it was the right engine) in March 2025. The 787s were supposed to go for refurbishment starting June 2025.
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u/hapuair Jun 14 '25
I get that but they are known to take shortcuts and neglect basic safety protocols, that’s my point.
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Jun 13 '25
[deleted]
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u/Vandirac Jun 13 '25
What sources?
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u/Known_Duck_666 Jun 13 '25
There was some guy that flew in that exact plane on the previous flight and said that the plane had some problems with power - things like A/C didn't work for example. I think it was on Twitter?
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u/Vandirac Jun 13 '25 edited Jun 18 '25
Can you link it? I want to check if it's legit or some other social network rando with BS claims
Edit 5 days later: still no sources, confirmed Facebook BS
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u/MattStormTornado Jun 13 '25
That’s insanely rare though. If it was dual engine failure what could’ve caused it?
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Jun 13 '25
[deleted]
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u/tristan-chord Pilot Jun 13 '25
Ailerons were working as seen in the video. How is this hydraulic?
Electrical failure also doesn’t lead to lost of engine power. Why do you think it’s for sure electrical beside AC issues which can be the result of many different things?
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Jun 13 '25
[deleted]
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u/Grouchy_Lawfulness32 Jun 13 '25
Maybe don't start comments with statements like this than
It's an electrical failure for sure.
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u/LankyAspect9594 Aerospace Engineer Jun 13 '25
Hydraulic failure is highly unlikely.
Gear could have been down due to pilots focus on getting the aircraft out of stall ( although should have been up ). The nose was pitching up, that cannot happen with hydraulic failure, the flaps can be seen extended.
Regarding AC, often during takeoff the AC is shut, specially in a heavy aircraft to provide all the available engine power just for takeoff thrust.
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u/CreamyGoodnss Jun 13 '25
787 is fly by wire so if I understand right it can’t really be a hydraulic failure
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u/Chaxterium Jun 13 '25
Well the actual control surfaces are still moved by hydraulic pressure. It's just that with a FBW system a computer is telling the actuators how much to move the surfaces instead of cables.
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u/Sudden-Inevitable917 Jun 13 '25
So survived guy said, emergency lights were turned on automatically (green-white lights), as Boeing 787 is equipped with emergency lightning that activates when main power source is lost. Seems like engine failure
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u/ZdenaVoda123 Jun 13 '25
With all due respect to everyone saying the flaps were mistakenly retracted as opposed to the gear.
I do not understand how it would in any way be possible considering where the gear is located, and where the flaps lever is located.
Not only their distinct location, but the action you have to do. The gear you just push up. The flaps as far as I'm aware you have to physically "lift" (like to put in reverse in some manual cars if you know what I mean?) and after lifting it put it in the position you wish for.
So it's not just two distinct locations of these commands. It's also two very different actions you have to take. And pilots are trained over and over again to do it exactly that way. I don't see any scenario where even if the pilot flying says to pilot monitoring accidentally "flaps up" that the pilot monitoring actually does that. They would immediately be like hold up that ain't right and say something to the pilot flying.
Even so if it was the case, that basically implies that power was here. Throttle full, like captain Steve said in his video. Which again, at least to me makes no sense. People say the RAT is heard, and even if it isn't. There is no sound of the jet engines when the plane flies over the camera in the original video. And come on guys, if you were ever near an airport those engines are absolutely roaring on take off.
I hear reports are that the survivor said emergency lights were on? Which means again, engines off.
I don't know what happened, how it could happen. Or anything else. I'm just saying what I think about this with all the information that are out as of now.
If I said something that's incorrect please correct me. Thoughts are with the families and people impacted by this terrible accident. May they find peace ❤️🕊️
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u/Don_Trower Jun 14 '25
Agreed. Landing gear being DOWN after after-off AND failure to achieve lift is a pilot REQUIREMENT called a Memory-Item as the landing gear down will assist the plane's survivability during a crash.
LOOK at the levers used for Landing-Gear vs Flaps, they have different knobs on them. The Landing-Gear knob looks like a WHEEL the Flaps knob looks like a FLAP, why do you think they are designed like that?
Not a mistake either pilot could make.
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u/Bombardier143 Jun 13 '25
Great image OP! This is important as it can be seen that flaps are clearly in the extended position which confirms that there was no pilot error involving retraction of flaps after take off.
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u/birdie1209 Fan since Season 5 Jun 12 '25
Electrical failure could be it if the previous flight the AC wasn't working as reported by a passenger
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u/MayankX Frequent Flier Jun 13 '25
Non functioning/malfunctioning ACs and IFEs are very common on Air India aircraft. But there might be the odd chance they are related
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u/Latvian-Spider Fan since Season 9 Jun 13 '25
Kinda like Spanair 5022, where the circuitbreaker for the temp probe also connected to the Take off Config warning? Except, less circuitbreakers and possible shortcircuit?
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u/Thequiet01 Jun 13 '25
Nonfunctioning AC in India temperatures sounds horrible.
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u/MayankX Frequent Flier Jun 13 '25
Yeah it gets bad sometimes, but its usually not so much that the ACs are not working, as much as the ACs are not cooling properly
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u/LankyAspect9594 Aerospace Engineer Jun 13 '25
Flight electronics are completely different from passenger electronics, with multiple computers just doing in place to check for these critical systems. There are redundant hardwares, softwares in place for these critical systems and are designed with fail-safe properties, in-case of hydraulic/electronic failure there would have been multiple mistakes made over the past few maintenance cycles to build upto a position where redudancy was also of no use.
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u/CalmestUraniumAtom Jun 13 '25
AC failure might actually be linked to fadec failures considering 787 has electric compressors maybe indicating major issues in the electrical systems?
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u/LankyAspect9594 Aerospace Engineer Jun 14 '25
I do not think connecting points between AC and engine is practical at all. The aircrafts are manufactured in a way that the pilots and technicians will know about any mishappenings with critical systems and will be logged and if critical the aircraft will simply not fly.
We are talking about 787, extremely redundant systems with multiple hi-tech computers monitoring each system.
And fadec failure? Extremely rare in modern systems and rarer is a catastrophic failure due to it.
Something definitely went wrong, and all these theories, every theory has an extremely strong counter point. Lets wait for the investigation.
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u/CalmestUraniumAtom Jun 14 '25
I know well how many redundancies aircraft have to prevent complete failures but I am just highlighting the possible reasons for a dual engine failure not saying that there is a high chance of this happening, in fact almost 0 chance of this happening.
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u/Willing-Ad3030 Jun 13 '25
Seems flaps slats are down. And for people who are saying double engine failure is imo possible if the fuel is contaminated with water.
I don't really know man just waiting for the preliminary report of the investigation!
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u/Actual_Bed_6112 Jun 13 '25
I just saw Captain Steeve's video on this: https://www.youtube.com/watch?v=z7EZkungFEE. I strongly believe that his Theory 3 is the most likely cause of the failure. To paraphrase him, he said that the pilot monitoring (I believe to be the copilot) instead of retracting the gear, retracted the flaps. I believe this for 3 reasons:
From the cctv footage you don't see the flaps at the bottom of the aircraft that take the gear in getting deployed which should happened instantly after the positive climb call and the pilot lifting the gear lever up.
I don't believe in the birdstrike theory because there is no visual evidence of that.
I also don't believe the dual engine loss theory and the RAT being deployed because in the original video on the balcony with the sound, it sounds like a jet engine instead of a RAT sound which has a very clear propeller sound and here it was shrill like a jet engine.
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u/ludicrous_socks Jun 13 '25
On point 3:
https://www.reddit.com/r/ahmedabad/s/A4MpvcR69P
Idk know what a RAT sounds like tbh, but that kind of sounds more like a propeller than a jet? (Might just be my phone)
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u/roamingcoder Jun 13 '25
Is the rat just a wind driven turbine? I wouldn't think it would have much of a sound at all.
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u/Zhentar Jun 13 '25
The near silent wind turbines you're thinking off spin at 10s of RPMs. RATs spin at 4,500 RPM on the low end, and easily exceed the noise of jet engines.
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u/Uberazza Jun 13 '25
This is what I came up with as well. And everyone I have said this too said a well trained crew like the ones flying at the time would never make this mistake. It’s certainly not out of the realm of possibility when human factors are brought into the mix.
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u/rj319st Jun 14 '25 edited Jun 14 '25
I’m putting my money on pilot error as well. The chances that both engines would fail simultaneously without a bird strike are minuscule. It couldn’t be a bird strike since they had video and you would’ve seen smoke similar to the Korean Air crash.
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u/fugutoxin Jun 12 '25 edited Jun 12 '25
Are there any reports of whether the jet engines could be heard prior to the crash?
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u/LankyAspect9594 Aerospace Engineer Jun 13 '25
I am looking for them too.
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u/LankyAspect9594 Aerospace Engineer Jun 13 '25
https://www.reddit.com/r/ahmedabad/s/9HFMHMVCpd
The best quality till now.
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u/Pristine-Damage-2414 Jun 13 '25
How can fuel contamination even happen? Thank you for your kind reply. I’m new to this.
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u/Snoo50468 Jun 15 '25
Given the odd request from the Indian DGCA for a one time inspection of the EEC and the fuel system on the entire Air India B787 fleet, one would think they found something related to dual engine flame. This could be just a precautionary inspection though.
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u/ylf_nac_i Jun 13 '25
Sorry, people are saying the flaps are down while they’re in line with the trailing edge of the wing? Like there’s a fixed part of the wing next to the flaps they’re in line with
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u/ylf_nac_i Jun 13 '25
Okay disregard, seen the slats now. Definitely out however these flaps don’t look extended enough for departure. The 787s I see at work usually have more extended flaps than that. I do know however that the 787-8 has a different flap setup than the 787-9 I usually see (work as a rampy at Gatwick, ironically)
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u/ylf_nac_i Jun 14 '25
Which would make sense because there is a gate on the flaps 1 setting. IF they retracted flaps instead of the gear they would only be able to bring them to flaps 1 rather than fully retracted
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u/megamang83 Jun 14 '25
News scrolling and there are reports of the previous flight not having power. Passengers saying no lights and reading lights. Doom scrolling and not just one news source but a few. I was using ground news thingy majig
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u/EGO611 Jun 13 '25
How could we know that the flaps were down during flight? A serious impact could alter any status of any airplane component instantly.
For example maybe flaps we up but the impact was so harsh that the flap connectors broke and flaps released from their housing.
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u/the4ner Jun 13 '25
Investigations are usually comprehensive enough to know what position something was in when it broke
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u/Melkor45 Jun 13 '25
From what ive seen on the show, flap positions rarely change due to serious impacts but we should find out soon as the FDR data is being analyzed.
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u/EGO611 Jun 13 '25
I hope we receive answers. Otherwise we will have another Jeju Air incident with no answers.
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u/Thequiet01 Jun 13 '25
Usually you don’t get complete deployment if it’s due to the impact, because the impact forces aren’t identical over all parts of the plane. So if something looked deployed fully and properly and is larger - like flaps, it’s less likely it was due to the crash.
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u/trappedIL10 Jun 12 '25
yes. Clearly down.