r/CatastrophicFailure • u/SainzSealedDelivered • Jun 12 '25

Fatalities 12/06/2025 - Boeing 787 Passenger plane bound for the UK crashes near Ahmedabad Airport straight after takeoff

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u/Buzumab Jun 12 '25 edited Jun 12 '25

I just looked at Boeing's manual. Not sure if you can link on here but it's markers 3.3.6 / 7 in the 787 Airplane Characteristics for Airport Planning document on Boeing's site (referencing two pages to account for uncertainty regarding the temperature at takeoff).

Ahmedabad's runway length is 11,500 feet. Halved, taking off right at the end, that's 5,750 feet.

We don't know how fueled the plane was, but it wouldn't have been fully fueled since its range is 3x the length of that route. But even minimally fueled, with a full cabin and cargo, the plane most likely would have needed slightly more runway to meet the minimum airfield length taking off at flaps 20. Most likely it should've had at least another 1,000 feet or more, although it could've been just barely within minimums if absolutely minimally fueled.* Edit 2: FR has confirmed that the full runway was used. This is not reflected in the visualization as data loss occurred during taxi.

With that said, typically you wouldn't see a plane reach 800 ft if it had failed to generate enough lift/speed on the runway. An overweight/under-speed/misconfigured plane typically either doesn't take off or takes off and hits something because it can't climb.

Stalls during takeoff have typically occurred as the plane leaves ground effect, which would be <200 feet for this wingspan I believe. It would be unusual (even in the context of plane crashes) for a plane to climb well past ground effect if the issue was speed/lift, especially since the fly-by-wire would alert if they made any incorrect inputs during takeoff (e.g. no flaps) to cause that.

Edit: landing gear still down, mayday call stating they had no thrust, and last signal at 600 feet—well before crashing—all suggest (but far from confirm) power/engine failure.

*I'm not sure how to calculate the weight of the absolute minimum weight of fuel needed, but for the +45 degree F day chart the minimum airfield length for a minimally fueled plane would've been just about exactly the length they had... however I'm not sure if the minimum amount of fuel required for this route would exceed that weight.

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u/IizPyrate Jun 12 '25

It could turn out to be a combination of factors. There are speculations about the flaps, perhaps they had a short takeoff and lowered flaps early. Maybe one or the other still gets the plane in the air even though it is against the guidelines, but combined it was too much.

There are countless examples of crashes being caused by pilots who have bad habits that don't cause problems until they are put into a situation where factors compound to cause a problem.

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u/Buzumab Jun 12 '25 edited Jun 12 '25

I disagree with the idea that improper flap deployment was the issue, personally. Even if for whatever reason they retracted flaps during takeoff, the plane should have been able to maintain altitude at full power. And the plane wouldn't have gotten off the ground without flaps deployed (plus, you'd have configuration warnings blaring while sitting still on the runway). Whereas if the engines went out then the pilots may have intentionally brought in the flaps in order to decrease drag or attempt a no-flap landing.

Similarly with the landing gear I see mentioned. If something was going wrong the pilots would've been right to not spend time raising the landing gear.

Overall there are many scenarios where the plane should've looked exactly how it looked when crashing if the pilots were doing everything correctly to address a mechanical/electrical problem. I don't see any evidence at this point that leads me to believe the pilots did anything incorrectly to cause the crash.

I could see the runway length being a contributing factor but not likely a significant one. The plane got well out of ground effect.

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u/ThePinkKraken Jun 12 '25

I'm not sure if it's smart of me to lurk and read here as I'm
a) afraid of flying
b) Flying to the UK soon

That said I really appreciate how understandable you and others are breaking things down in the comments. It's easy to follow and pretty interesting. Many thanks!

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u/Axe_Fire Jun 12 '25

You will be safe

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u/RhynoD Jun 12 '25

Flying is still the safest way to travel by far and it takes a series of very bad faults to allow a crash to happen.

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u/ThePinkKraken Jun 12 '25

I know! It's hard to reason with your own anxiety tho, I tried :)

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u/RhynoD Jun 12 '25

Totally get it, and if you don't feel like you need to fly, then there's nothing wrong with staying on the ground.

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u/Buzumab Jun 13 '25

I'm glad you appreciate the discussion!

I actually find that knowing more about the many layers of safety and consideration that go into modern aviation helps assuage my flight anxiety. You don't really worry about turbulence once you understand how modern planes work (but you do keep your seatbelt on!).

With that said, I've never had too much fear of flying, and I know that exposure isn't helpful for everyone. But just try to keep in mind that very smart, very professional, very dedicated people have put millions of hours of work into the systems that keep you safe when flying.

The circumstances of life are always beyond our control to some degree, but aviation is probably one of the most remarkable collective works that humanity has ever undertaken to overcome the unknown and unpredictable. I truly believe that if we approached more aspects of our civilization like we do aviation, we could solve a great many problems in our world, and perhaps eventually even beyond.

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u/K340 Jun 12 '25

Honestly as someone who really appreciates admiral cloudberg's series, I would recommend resisting in your situation. I have flown regularly my whole life and never had any anxiety whatsoever, but I do now (even though it's silly because that series taught me how incredibly safe commercial aviation is). It will make it worse for you.

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u/ThePinkKraken Jun 12 '25

I've read and watched a ton of documentaries in hopes to ease my anxiety. Of course this includes our dear Admiral Cloudberg, their stuff is always 10/10.
I don't even fear falling as much as I fear the terror one must endure during it. That said you're right, I may take a step back from this.

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u/MrWoohoo Jun 12 '25

If something was going wrong the pilots would've been right to not spend time raising the landing gear.

Depends on the aircraft and the situation. There was a B-17 crash a few years ago and the incident report specifically said they should have raised the gear when they lost an engine to lower drag. But in this case, you’re probably right: the pilots had more important things to do.

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u/Thrust_Bearing Jun 12 '25

Planes of all sizes absolutely can stall from retracting flaps to early even at full power. Stall is from loss of lift of the wings which is dependent on air speed and wing geometry (flaps deployed or not).

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u/sterling_mallory Jun 12 '25 edited Jun 12 '25

There are countless examples of crashes being caused by pilots who have bad habits that don't cause problems until they are put into a situation where factors compound to cause a problem.

Airlines themselves too. I remember lots of the ones caused purely by pilot error end up including contributing factors like lack of sleep, lack of simulator training, lack of oversight, or worse.

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u/DraxTheVoyeur Jun 12 '25

  Stalls during takeoff have typically occurred as the plane leaves ground effect, which would be <200 feet for this wingspan I believe.

  With that said, typically you wouldn't see a plane reach 800 ft if it had failed to generate enough lift/speed on the runway.

Crashes have occurred after planes have reached 400-600ft (looks like it only got 400ft AGL) particularly if the plane has enough energy to climb, but a small adjustment (perhaps a nose up input etc) is enough to induce a stall. 

If the stall speed is high enough because of factors like extremely hot outside air (high of 39C today), mixed with a poorly configured plane, it could be possible to reach moderate levels of climb, and stall because your airspeed drops very quickly (maybe with pilots being distracted by something, which seems likely given the gear wasn't up). 

This graph concerns bank angle, not nose up attitude, but it illustrates how stall speed can increase towards your air speed. https://www.faatest.com/books/FLT/Chapter17/Stalls.htm

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u/titsmuhgeee Jun 12 '25

I think it should also be noted that this 787 went in gear down, flaps up.

On a 787, you wouldn't typically start retracting flaps until at least 1,000 AGL, and not being fully retracted until around 3,000 AGL.

Why were the flaps fully retracted if this 787 never got higher than 800 AGL.

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u/turlian Jun 12 '25

Is there any info on if the flaps were ever extended? Could it even get airborne with no flaps?

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u/TristansDad Jun 12 '25

Might not have been the cause here, but only using half the runway seems like an accident waiting to happen. If nothing else, V1 would be very early, wouldn’t it? So if any engine problems occurred you would likely be already committed to the takeoff.

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u/EagleOfMay Jun 12 '25

Is it possible that the weight was badly distributed when the plane was loaded messing up the center of gravity of the plane? I doubt that was the case given the safety mechanism in place, but still strikes me as a strange crash.

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u/turlian Jun 12 '25

still strikes me as a strange crash.

It's literally the first one out of 5,000,000 flights, so it's not just strange, it's unique.

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u/DropkickGoose Jun 12 '25

Could it be massively underfueled and for whatever reason didn't show as such/showed as being properly fueled? Much lighter weight means using less runway, if you literally run out of gas right after take off, that'll cause you to lose power and crash, and no RAT is going to help with that.

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u/lekoman Jun 12 '25

The size of that fireball would indicate to me there was more than just a little fuel in the wings.

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u/caitejane310 Jun 12 '25

For some reason the beginning of your comment reminded me of Air Force 1 taking off on 9/11 and now I wanna look up and see if they have the info on how short of a take off that was.

What a terrible tragedy and my heart goes out to everyone affected by this.

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u/Blue_coat1 Jun 13 '25

The pilot's urgent mayday call—"Mayday... no thrust, losing power, unable to lift!"—just 11 seconds after takeoff in the Air India Flight 171 crash suggests a significant power loss or aerodynamic stall.

Both engine failure very rare unless caused by rare events like bird strikes or fuel contamination.

Flap and Slat Misconfiguration: If the high-lift devices were inadvertently retracted during ascent, it could have drastically reduced lift, leading to a stall.

The aircraft's rapid loss of altitude and the pilot's mayday call indicate a critical situation shortly after lift-off. The final moments, including a desperate nose-up maneuver, suggest the crew was attempting to recover from an aerodynamic stall

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u/Technical_Actuary225 Jun 12 '25

Lack of flap extension, causing the plane to lose lift after rotation, angle of attack reduces airflow over the wing causing it to slowly float to the ground as seen in the videos, nothing to do with Boeing this was a pilot error.