Air India Flight AI171 (Boeing 787-8) Crash

[Just a civilian pilot]

In terms of the crew in routine operation, sure. The automation helps. But there’s also computer menus where the pilots have to know how to navigate. I have enough issues going through a Tesla touchscreen, but the pilots have a lot of stuff.

And under the hood, there’s a lot more complexity because of all the automation. Millions of lines of software. Even the engines have a control computing unit.

https://www.collinsaerospace.com/wh...actuation/electronic-engine-controllers-fadec

Let’s put it this way; pilots coming from older aircraft found the A320 extremely complicated and the coarse very tough. We used to have pilots avoid upgrading on the higher paying A320 and upgrade on the DC9 because it was a lot easier back then.

Today, you put an Airbus pilot in a basic B727 and they would find it harder because they have become automation dependant ( AP, auto thrust, VNAV ).

You would be surprised how many pilots I see who descend far too early because the VNAV is off and they just follow it.

IMHO, they were better pilots back then.

 

[Just a civilian pilot]

From the Website The Aviation Herald FWIW.

On Jun 20th 2025 government officials stated, that India's AAIB is currently looking into another case of dual engine problems with an A321 that happened in London Gatwick in 2020, see: Incident: Titan A321 at London on Feb 26th 2020, left engine surged, engine stall indications for right engine, that was caused by fuel contamination. It appears on preliminary findings, that there was no error in the cockpit, it appears that as soon as the flight became airborne the power failure occurred leaving the aircraft unable to climb to a safe altitude.

 

[E365]

Interesting video…

A *theory* that an electrical fault cascaded into both engine fuel shutoff valves closing automatically.

 

[Just a civilian pilot]

Interesting video…

A *theory* that an electrical fault cascaded into both engine fuel shutoff valves closing automatically.

The aircraft apparently used up the entire runway and I don’t see how electrical problems could contribute to that.

You would think the crew would be alerted if they had serious electrical problems even on take off while fuel ( read about the Titan incident…..no warning until 500 on that flight ) problems may not have been obvious to the pilots, until they started losing thrust.

Why the aircraft used up so much runway is unusual.

You would almost think it didn’t have full thrust taking off and then they just quit after take off but I can’t see any aircraft not alerting pilots when they don’t have enough thrust assuming they did the take off calculations properly if reduced thrust.

That said, on the A320, ensuring we have the proper thrust is a call the PNF makes proper to 80 knots on take off…..” thrust set” ( N1 has to be within 1% or “ low power” call is made ).

 

[MolaKule]

Interesting video…

A *theory* that an electrical fault cascaded into both engine fuel shutoff valves closing automatically.

I think this is a far-fetched conjecture.

Let's see what the DR shows.

 

[Just a civilian pilot]

From the Website The Aviation Herald:

Something was going on even before the plane rotated and climbed to 600 feet IMHO.

I watch heavy B787s take off for Japan from my base and they don’t come close to using up the entire runway and they are less than 10,000 in some cases.

“On Jun 15th 2025 Government Officials reported the aircraft had a longer than normal takeoff run and used almost all of the 3505 meters/11499 feet long runway. 38 fatalities on the ground have been confirmed so far.”

 

[Number_35]

From the Website The Aviation Herald:

Something was going on even before the plane rotated and climbed to 600 feet IMHO.

I watch heavy B787s take off for Japan from my base and they don’t come close to using up the entire runway and they are less than 10,000 in some cases.

“On Jun 15th 2025 Government Officials reported the aircraft had a longer than normal takeoff run and used almost all of the 3505 meters/11499 feet long runway. 38 fatalities on the ground have been confirmed so far.”

Does this imply the engines were not producing the expected thrust?

 

[Pablo]

Does this imply the engines were not producing the expected thrust?

That is what popped in my feeble mind. But as to cause- TBD

 

[4WD]

From the Website The Aviation Herald:

Something was going on even before the plane rotated and climbed to 600 feet IMHO.

I watch heavy B787s take off for Japan from my base and they don’t come close to using up the entire runway and they are less than 10,000 in some cases.

“On Jun 15th 2025 Government Officials reported the aircraft had a longer than normal takeoff run and used almost all of the 3505 meters/11499 feet long runway. 38 fatalities on the ground have been confirmed so far.”

Yep, unloaded for air shows - 787’s launch like fighter jets …

 

[Just a civilian pilot]

Does this imply the engines were not producing the expected thrust?

Let me put it this way. The only time ( we try to take off with reduced thrust when take off performance calculations allow it to save engine wear…..lowest EGT ) we read reports about aircraft using up a lot more runway is when they underestimate the take off weight and don’t use enough reduced thrust as a result ( plus the V speeds are too low which is why tail strikes are reported as they try to force the plane into the air by pulling full back once they realize it’s not rotating normally at Vr speed ).

The thing I notice about this B787 rotation was that it appeared normal ( just took longer, more runway to reach Vr ) plus there wasn’t a tail strike leading me ( just my opinion ) to think they didn’t make any take off calculation errors and, for whatever reason, the aircraft engines weren’t producing enough thrust as strange as that sounds to me as a pilot given pilots ( only won’t realize if they make a take off performance calculation mistake ) know if the engines aren’t producing the required thrust by the time they apply take off thrust.

What are the chances it used up the entire runway and then wasn’t able to climb after 600 feet because appears it lost thrust on both engines, the landing gear is still down and the RAT apparently extended?

This is my opinion but I try to be logical about what could have caused it. All kinds of crazy theories.

 

[Just a civilian pilot]

Does this imply the engines were not producing the expected thrust?

See below please ( above now lol ).

 

[fdcg27]

From what I gather reading here and there, the current consensus among those who actually fly airliners is that there was a severe loss in engine output at some point after or around rotation, apparently enough to auto deploy the RAT and maybe autostart the APU.
The question is why and there remain a variety of theories on that, from fuel contamination to software errors not heretofore manifested in what is now a fully mature type and engine.
Given some altitude to work with, the crew could have probably worked it out or worst case found a better forced landing site, but they had neither time nor altitude to do anything and had to descend straight ahead into the structures there. Must have been horrifying for them with no options and no control over what was about to happen.
Incidentally, lightly loaded any turbofan airliner can perform like a fighter, especially a wide body twin.
These airplanes were built to carry a load and it is not unusual for the useful load at MTOW to exceed the OEW of the aircraft.

 

[4WD]

From the Website The Aviation Herald:

Something was going on even before the plane rotated and climbed to 600 feet IMHO.

I watch heavy B787s take off for Japan from my base and they don’t come close to using up the entire runway and they are less than 10,000 in some cases.

“On Jun 15th 2025 Government Officials reported the aircraft had a longer than normal takeoff run and used almost all of the 3505 meters/11499 feet long runway. 38 fatalities on the ground have been confirmed so far.”

good take off from the good guys
(and the spool up sounded sweet) …

 

[edyvw]

OK, how in the name of Zeus they are going to meet ICAO deadline of 30 days? They probably had dual loss of thrust and they are dillydallying with boxes:
https://www.reuters.com/world/india...india-jet-still-india-ani-reports-2025-06-24/

 

[IndyFan]

I have not read every response in this thread, so forgive me if I missed it.

Has there been any talk of a bird strike? Maybe it could have hit a large flock of birds as it was nearing rotation....too fast and far along to abort but enough effect that it caused either engine shutdown or reduced thrust enough not to permit climb out?

Or maybe this has been ruled out. There just aren't too many causes and the odds are very long for both engines to lose thrust at the same time.

I don't see birds in the video, but it is so grainy that small birds might not be visible.

Just wondering if this is being explored or if it has been ruled out.

 

[Just a civilian pilot]

I have not read every response in this thread, so forgive me if I missed it.

Has there been any talk of a bird strike? Maybe it could have hit a large flock of birds as it was nearing rotation....too fast and far along to abort but enough effect that it caused either engine shutdown or reduced thrust enough not to permit climb out?

Or maybe this has been ruled out. There just aren't too many causes and the odds are very long for both engines to lose thrust at the same time.

I don't see birds in the video, but it is so grainy that small birds might not be visible.

Just wondering if this is being explored or if it has been ruled out.

Birds were ruled out.

From the website The Aviation Herald:

On Jun 13th 2025 the DGCA reported, that initial preliminary findings rule out a bird strike as no bird carcasses have been found.

 

[fdcg27]

OK, how in the name of Zeus they are going to meet ICAO deadline of 30 days? They probably had dual loss of thrust and they are dillydallying with boxes:
https://www.reuters.com/world/india...india-jet-still-india-ani-reports-2025-06-24/

The thirty day timeline applies only to a preliminary report, which might be as vague or as detailed as the state leading the investigation is able or willing to make it.
In this case, the AAIB might simply write of possible causes considered and dismissed and that it has arrived at the working hypothesis that a significant or total loss of engine output occurred at or shortly after rotation, the causes for which are not yet determined and remain under investigation.

 

[Just a civilian pilot]

https://www.icao.int/Newsroom/NewsDoc2022/ICAO-Fact-Sheet_Accident_Investigation - 2022-04.pdf

 

[edyvw]

The thirty day timeline applies only to a preliminary report, which might be as vague or as detailed as the state leading the investigation is able or willing to make it.
In this case, the AAIB might simply write of possible causes considered and dismissed and that it has arrived at the working hypothesis that a significant or total loss of engine output occurred at or shortly after rotation, the causes for which are not yet determined and remain under investigation.

Yes, they could do that. However, one would expect there would be urgency to find an answer considering number of 787’s in use.

 

[fdcg27]

Yes, they could do that. However, one would expect there would be urgency to find an answer considering number of 787’s in use.

We agree on that.
It's also important that a definitive probable cause be identified and that may well take quite a bit more than thirty days.
There is also a background chorus of interested parties trying to escape any culpability.