Air India AI171 B787 Crash: A Pilot’s Analysis

The tragic news of an Air India B787 crashing on departure from Ahmedabad this morning has shocked many around the world. This article aims to cut through the media noise and provide people with an early understanding of what may have caused this accident from a pilot’s point of view. I want to preface everything below with our most heartfelt thoughts being with the families of those impacted, including the pilots, who’s actions will be all too easy for the world’s media to judge.

The article is a dynamic one and will be updated as more information becomes available.

What We Know

Flight AI171 departed Ahmedabad on 12th June 2025 with 242 people on board on it’s way to Gatwick airport. It made it to an altitude of around 625ft, before descending into a residential area and crashing. Fatalities aren’t confirmed at the time of writing, but looking at the footage and the crash site, it’s unlikely there will be many survivors onboard, and there will likely be many casualties on the ground as well as some of those on the ground.

Update – 16 June – New Evidence

The original video of the crash has emerged in the media, this one with much clearer visuals and audio than the initial one that circulated. Although the new video is the same footage as before, the enhanced audio and visuals reveal a lot. The new video can be seen in this video. So what does it tell us?

RAT

The Ram Air Turbine (RAT) is a small propeller-driven turbine that automatically deploys from the bottom of the B787 when certain systems fail, to provide electrical power and hydraulic pressure to the relevant systems.

In the above video, it looks like the RAT has been deployed. Not only that, with the clearer audio, the B787 sounds more like a propeller-driven aircraft as it comes past, as opposed to a jet. Eyewitness reports from the sole surviving passenger of the crash seem to indicate that just after take-off, all the lights onboard flickered, and there was a bang heard in the cabin. The above is all consistent with the RAT dropping out, and the lights flickering as the electrics were switched over to be supplied by the RAT.

One of the situations in which the RAT automatically deploys is dual engine failure. The fact that the RAT is deployed, and there doesn’t appear to be much of a ‘jet’ noise in the video, would suggest maybe a dual engine failure could have occurred here.

Dual Engine Failure

Although the odds of a dual-engine failure on a modern-day airliner are impressively small, as I said in the initial article, it has happened in the past. This is again extremely early days, especially with this new information, but let’s explore potential causes of dual engine failure, and whether they’re applicable here:

Mechanical Failure – The Boeing 787 engines have faced many issues over the last decade, so mechanical failure could be one line of thought. However, the engines operate mostly independently of each other, so the chances of suffering mechanical failure simultaneously, in two separate jet engines, are extremely thin.

FOD ingestion – Foreign Object Debris (FOD) ingestion into the engines is a more likely cause of dual-engine failure than simultaneous mechanical failure. It’s happened over the Hudson, and is believed at this stage to be the cause of the recent 737 crash in South Korea. In both scenarios, the cause was birds being ingested in the engines. In the case of Air India AI171 however, no bird remains were found on or near the runway. Also, if something is ingested into an engine causing significant damage, you’d expect to hear loud thuds and bangs as the damaged engine continues to try and run. You’d also expect to see evidence of damage from out the back of the engine – either flames or pieces of debris. There doesn’t appear to be any of the above in either video. One theory is that the engines ingested something once it was past the end of the runway, so it’s hard to locate any remains, and both engines failed instantly, in a way that didn’t produce and audible or visual indications on the videos.

Fuel Contamination – Another cause of dual-engine failure would be fuel contamination. If the fuel put into the aircraft was contaminated somehow, it could well cause both engines to flameout at the same time. Fuel contamination can happen before it’s put into the aircraft tanks, or once it’s in.

My initial thoughts here would be if the fuel put into the aircraft was already contaminated, other aircraft that were also refuelled that day would likely also suffer engine issues, but none have been reported. This means if fuel contamination were the cause, it’s likely to have happened inside the tanks, potentially caused by condensation or vapour.

Fuel Starvation – In terms of causes of a dual-engine failure that seemingly has no outside audible or visual indications of major damage, fuel starvation must be considered as a potential cause. A multitude of things could cause fuel starvation to the engines (blockage in the fuel lines, fuel valves closed, frozen fuel) the outcome will often be the same: a rapid loss of power on both engines, as happened with British Airways flight 38.

Single Engine Failure

Could the failure of just one engine have caused this? At this time, although still definitely possible, it seems unlikely. Modern-day airlines should all be able to climb away from an airport after the loss of one engine. The loss of one engine alone shouldn’t automatically deploy the RAT, and the procedure for a single engine failure wouldn’t order the pilot to manually deploy it either, unless it was accompanied by a separate hydraulic or electrical failure (not that the pilots had time in this scenario to work through any procedures. Given that in the new audio, the sound of the RAT is so clear, it really does seem to indicate neither engine was running at anywhere near full power, if running at all.

We’re still waiting for work from the investigators on the contents of the black box, which should hopefully provide the answers everyone’s looking for.

Early Analysis

It’s VERY early to draw conclusions, but there has been piece of footage already released that can show us a few key things.

From this footage, it looks like the aircraft simply doesn’t have the performance to continue flying. It does however, look like the pilots were very much at the controls and fighting until the end, as the nose is lifted higher as the aircraft descends closer to the ground, as if the pilots were trying to cushion the landing before disappearing from view.

My initial theories as to the potential reasons for the lack of performance are that either the aircraft stalled on take-off, or suffered a dual engine failure, or both. Let’s take a quick look at both possibilities and explore a bit more around them:

Stall On Take-off

Due to the amount of technology onboard, modern day airliners are extremely difficult to stall, the B787 included. It’s not, however, impossible. Unlike an Airbus, the Boeing 787 doesn’t appear to have any systems that actively prevent a stall, rather it offers the pilots multiple cue’s to help them recognise they’re nearing a stall state, and relies on the pilot to input the correct action to prevent a stall happening. It does offer a few ‘soft’ protections, but no outright overrides.

What could cause a stall on takeoff? Essentially it’s when the aircraft is not travelling fast enough through the air, for the given weight and configuration of the aircraft. Pilots will do ‘performance’ calculations before takeoff to work out the take-off and climb out speeds, using the current weather and aircraft weights. Inputting wrong figures, or conducting a take-off that wasn’t in-line with these calculations, could cause a stall. This could be a result of taking off from the wrong intersection on the runway, taking off in a different configuration as stated in the performance, or taking off in environmental conditions that didn’t match what you inputted into the performance software.

Clean Wing

One thing that really strikes me from the video is that the wing looks very ‘clean’, meaning there are no, or minimal flaps deployed. The video isn’t the best quality, so it’s hard to absolutely confirm this, but it certainly doesn’t look like like the wing is in a standard take-off configuration. For take-off, aircraft tend to have either the first of second stage of flaps deployed. This increases the lift the wing will give you at a given speed, ensuring you can climb away from the ground faster, and gives you better performance on shorter runways and in hot conditions.

Why could the wing be clean? Either the take-off flaps were never set in the first place, or they were retracted earlier than they should have been. Flaps aren’t retracted until at least 1000ft above the airfield. Given this aircraft only made it to 600ft, the flaps should still have been out.

If the wing is clean (no flaps deployed), the speed at which the aircraft will stall is greatly reduced. If the take-off performance figures were calculated based on flaps deployed for the departure, but then for whatever reason the flaps were not deployed, or retracted early, then it’s likely the aircraft could be put into a stalled state if trying to fly the same departure profile.

Landing Gear Down

Another thing that strikes me is that the landing gear is down. The landing gear is usually retracted at around 100ft, so it should have been retracted given the aircraft reached 600ft. There are a few reasons it could be down:

• The pilots extended the landing gear again when they realised they were going down. Although this would be a strange call to make, as it looks like the area they crashed into didn’t have anywhere to ‘land’ an airliner, and dropping the gear would create lots more drag, essentially bringing you down even faster.
• They forgot to, or were unable to retract it – this could fit in well with the theory of engine failure. During an engine failure their capacity may have been taken up with other things and the gear was forgotten. In the case of dual engine failure, there wouldn’t be enough hydraulic pressure available to raise the gear.
• They mistakenly retracted the flaps early, maybe instead of raising the gear. This fits in with the theory of a stall, or lack of performance. This is known as a ‘slip’, whereby you mean to do one thing, but do something else. If they retracted the flaps instead of raising the gear, the aircraft will be in a perelous position; no flaps to give the aicraft a higher stall margin, and gear still down causing huge drag and performance issues.
  

Engine Failure

Another genuine possibility is engine failure, either single or dual. With a single engine failure, the aircraft should still have been able to climb away from the ground. Dual engine failure would be a different story, especially that low to the ground. There’s not enough time to restart the engines, and it’s a case of damage limitation, just trying to put the aircraft down wherever will have the least loss of life.

While dual engine failure is very rare, it’s still a possibility. We saw it happen over the Hudson with US Airways flight 1549. Boeing’s 787 engines have faces lots of scrutiny over the past few years, with lots of the fleet being grounded due to engine issues. Although dual engine failure shouldn’t be ruled out at this stage, listening to the audio on the above footage, it sounds like the engines are running, and at quite a high thrust setting. If there was a catastrophic duel engine failure, you’d expect to hear less noise, or mechanical bangs and thuds as opposed to a normal jet engine sound.

Boeing

This is yet another major aviation accident involving a Boeing. Once again, it’s one of Boeing’s newest, state-of-the-art aircraft involved. It’s the first B787 crash, but not the first time one of their most up-to-date aircraft has been involved in a fatal accident recently.

Although it’s very unclear at this time whether this crash was caused by an aircraft issue, a crew issue, or a variety of other issues that may have nothing to do with the fact that it’s a Boeing, there’s no doubt that Boeing’s ever-worsening reputation when it comes to flight safety is going to be heavily under the spotlight once again.

What Happens Now?

Multiple air accident investigation groups will be sent to the crash site. Any countries with a connection to the crash will dispatch their own teams. The UK AAIB will be dispatched as there were Brits onboard, and some of the component of the aircraft are also British.

Over the next few days, the crash site will be examined thoroughly, before removing the wreckage of the aircraft to somewhere that investigators can spend even longer examining. The aircrafts black box will be recovered, giving investigators access to the cockpit voice recordings and all data recorded from the aircraft’s computers leading up to the accident.