Air India Flight 171 Crash: Unraveling the Mystery (Preliminary Report Analysis)

Tragic Air India's Boeing 787 Crash: Initial Speculation vs. Facts

An Air India's Boeing 787 took off for what should have been a routine nine-hour flight, but then ended up crashing into buildings just half a minute after departure. Why? What actually happened? Well, I will get to the details from the interim report soon, but first I want to talk about the period leading up to its release on the 11th of July, 2025. Unfortunately, in the immediate aftermath of this tragedy, there were no real updates from the investigators, which frankly isn't that surprising given how much they had to do and how careful they needed to be in weighing the information. But this also meant that there was a substantial information vacuum, which gave rise to wild speculation or even worse, real trash in the form of deliberate misinformation that a very large section of the public just wasn't equipped to distinguish from the truth.

The Challenge of AI-Generated Hoaxes and Critical Thinking

For example, several fake interim reports were circulated and one of them claimed that the captain's seat had slipped or fallen backwards, causing him to inadvertently pull back on the thrust levers without even realizing it. Now that actually did happen to an Air India Express flight, a Boeing 737-800, which I covered in a different video. But that also meant that these hoaxsters were now using a mix of AI tools and real stories to create narratives that initially looked really believable, thanks to details from that older story and its final report. Now I know that not everyone can quickly identify these scams. They are designed to deceive and they really do. And in events like this, it's always important to turn to reliable sources and to think critically, especially when you see something really shocking being sent to you from a friend or colleague. Since at least some of this fabricated material is based on real events and reports, it looks super convincing, even to industry insiders and that just makes my blood boil. Not only do we have a horrible tragedy on our hands, the first fatal crash of a Boeing 787 and the deadliest crash in a decade, no, we also have people knowingly spreading AI-generated nonsense just to get some temporary attention or for some other nefarious motives. That is actually a big part of why my team and I have been following this story closely and making frequent video updates for you guys, and I hope you appreciate that.

Preliminary Report Sheds Light on Air India Flight 171

But now, finally, we have a preliminary report, and while it still doesn't include any definitive conclusions, it sheds a lot of light on what happened. So this video is all about the facts here, what we do know and what it means, and also what we don't know, which is just as important. And it's also about what you can do from now on to remain well informed. This tragedy happened on Thursday the 12th of June, 2025, involving Air India Flight 171 from Ahmedabad to London's Gatwick Airport in the UK. Until this tragic event, Flight 171 was a daily service for Air India, departing early in the afternoon. And on this day, the aircraft had been scheduled to depart at 1310 local time.

Crew Details and Pre-Flight Checks for Flight 171

The flight's captain was a 56-year-old male who had a total flight experience of 15,638 hours, and nearly 8,600 hours was on the Boeing 787, of which 8,260 was as pilot-in-command. Now, earlier local news reports said that he was also a line-training captain with Air India and that he planned to retire soon, but that was not mentioned in the report. His first officer was 32 years old and had a total flight experience of 3,403 hours, of which 1,128 hours were flown on the Boeing 787. And it's important to note here that for this flight, the first officer was pilot flying and the captain was pilot monitoring. As part of their pre-flight preparation, the two pilots underwent some medical checks, including a breath analyzer test, which showed that they were both fit to operate the flight over to Gatwick. Both pilots also seemed to have gotten adequate rest before the flight, according to the report.

Pre-Departure Preparations and Taxi to Runway 23

One of the speculations we heard before the preliminary report was released was that the aircraft might have been carrying something that could have affected the instruments on board, but the load manifest showed that there were no dangerous goods on board this flight. Anyway, the pilots' fuel calculations, the rest of the load sheet as well as the V-speed calculations didn't raise any flags for the investigations either. Everything was apparently within allowable limits. Once the crew were ready, they taxied out for departure about half an hour behind schedule towards Runway 23. Now, Ahmedabad only has one runway, and its parallel taxiway doesn't run all the way to the threshold for Runway 23. And this meant that the crew had to taxi out and enter the runway from taxiway Romeo four, which is connecting close to about halfway down the runway.

Correct Takeoff Procedure Confirmed for the 787

Now, initial ADS-B data of the plane's taxi route was missing quite a lot of data points, which also created some initial controversy, where some suspected that the crew might have tried to take off from that intersection taxiway, Romeo Four but later reporting, and, of course, this preliminary report confirmed that the 787 did not take off from that midfield position. Instead, the flight crew backtracked to the threshold of the 3,505-meter, or 11,500 feet long runway, and then made a full length takeoff.

Takeoff Performance and Initial Climb Trajectory

Now Ahmedabad Airport is only 58 meters or 189 feet above sea level, but at the time of their departure, the high temperature of around 37 degrees Celsius, or 98.6 Fahrenheit, meant that the density altitude was around 3,200 feet. This requires a bit extra performance from the aircraft, but nothing that the Boeing 787 and its mighty GE NX engines couldn't handle on this day. And, of course, these are conditions that crews flying in and out of India would have been entirely familiar with. The crew started their takeoff roll at time 0807 and 37 seconds UTC, and then reached their V1 decision speed just under a minute later, which would be considered completely normal for their takeoff weight. The plane's weight on wheel switches then indicated that they lifted off at time 0808 and 39 seconds. And initially, all videos taken from this event showed that they achieved a normal positive rate of climb. But very soon, these same videos then showed that this climb flattened out and then quickly turned into a descent, one that the aircraft then never recovered from.

Debunking Flap Setting Speculation

And then, the preliminary report has been released, bringing some surprising and important updates. I'll come back to the findings in this report soon, but first let's look at some of the speculation that we all heard immediately after the event. For example, initially there was a big focus on the flaps. - The flaps were not down. - One theory being that the crew might not have set them correctly for the takeoff. We now know for a fact that this didn't happen. The flaps were correctly set. And, in fact, that mistake would have been a really difficult one to make in today's aircraft since several of our pre-departure checklists include these flaps and those checklists are electronic on the 787. And on top of that, the aircraft also knows where the flaps should be and therefore, will warn the pilots if they're not set correctly.

Visibility of Flaps and the 787's Carbon Fiber Design

Now the point I want to make here is that with the low resolution videos that we first saw, seeing if the flaps were actually set was really, really difficult. Even with good resolution pictures or videos, the slats might be a little bit more visible, but you have to look very closely to be able to tell how the trailing edge flaps are set. You see, one of the things the 787 is famous for is its carbon fiber composite fuselage and wings. And the fact that carbon fiber is much less prone to fatigue cracking also means that they can be very flexible and thin, making them more efficient. The Boeing 787-8 has two flap settings commonly used for takeoff, flaps five and flaps 15. And with flaps five, which we now know that these pilots were using for this takeoff, the leading edge flap surfaces, the slats, extend and the trailing edge flaps also extend rearwards, but they droop down only slightly, which is why they are so hard to see.

Ram Air Turbine (RAT) Deployment and Engine Focus

The next point that got people's attention were the engines, and there was an early reason for that, especially after the circulation of a better quality version of a video where a buzzing noise could clearly be heard, which led a lot of people to believe that the Ram Air Turbine, or RAT, had been deployed. Again, it's almost impossible to see the RAT in the videos, it's the size of a propeller of a small general aviation aircraft, but it would be spinning fast in the slipstream, causing that very characteristic noise. Its mast and door would be somewhat easier to see, but not from the rear and at the resolution of these videos. However, like I said, it is possible to distinguish the noise from the RAT, and other CCTV footage that we didn't get access to initially, but that was included in the preliminary report, showed that the Ram Air Turbine or RAT did indeed deploy, while the aircraft was still in its initial climb. The investigation also clarified that there was no significant bird activity close to the aircraft, which might have affected the aircraft's engines, but obviously the RAT's deployment meant that there was a lot of focus on the engines and what might cause them to lose power.

Understanding Dual Engine Failure and Fly-by-Wire Compensation

Now, there are many reasons why the RAT can deploy, and many of them does not involve a dual engine failure, but one-point worth highlighting here is that a dual-engine failure is not only extremely rare, it is also practically impossible for both engines to fail at the exact same time due to most technical faults. That's important to understand, because like I said earlier, we could see in one of the videos that the plane rotated, and initially started to gain altitude for several seconds, which means that it definitely did have power to begin with. But unless it lost power from both engines at more or less exactly the same time, we should be able to see a distinctive yawing movement when it happened. The engines are quite far apart out on the wings, and losing one means that it will suddenly generate a lot of drag, while the other engine would obviously still be producing thrust, and that asymmetric thrust should be visible. Now, even with something like fuel contamination, which could affect both engines, dual failures at the same time are practically impossible. And yet, we saw no such yaw on any of those videos, or any obvious signs of a technical engine trouble, like smoke coming out of one of them or surges. But there is also a small caveat to this. The Boeing 787 is a very modern airliner, complete with a fly-by-wire system, and that system is actually designed to automatically compensate for asymmetric thrusts using the rudder and the rest of its controls if necessary. The aircraft will even move the rudder pedals when it does this to let the pilots know what it is doing. So, in theory at least, that could explain why we can't really see any momentary yaw in the videos if the aircraft lost power from its engines at different times.

Puzzling Landing Gear Observations

Another point worth mentioning here is the landing gear. Like most wide body aircraft, the 787 has main gear legs that are equipped with trucks or boogies, which means that each leg has four wheels, two front and two rear. The preliminary report shows that the landing gear lever was found in the down and locked position, and there is no mentioning of the lever being moved during the entire accident sequence. Now, that is interesting, because when the landing gear is down and locked, the rear pair of the wheels on each boogie sits lower than the front pair. But before the gear can be retracted, the mechanism rotates the boogie so that the front pair of the wheels drops lower than the rear, and that's to allow the wheels to fit better into the wheel well base at the bottom of the fuselage. Now, normally, when the boogies do this rotation, the main gear doors open at pretty much the same time. And in at least one of the videos, the boogies seem to be rotated and the front wheel sits lower than the rear wheels on each leg, but the main gear doors remain closed. Now, we don't know why this happened, if the gear retraction sequence actually was initiated and not mentioned in the interim report, or if that gear position is a visual illusion of some sort. The 787 does include a lot of automation for its electrical and hydraulic systems, all of which could have affected what we saw without any action from the pilot. So we likely won't know the answer to that until the final report comes out.

Crucial Discovery: Fuel Cutout Switches Moved to Cutoff

But let's now see what we actually do know from this interim report. We first learned that the investigation was focusing on the fuel cutout switches, thanks to an article by Jon Ostrower in The Air Current from the 8th of July. Now, by the way, The Air Current is one of the most important aviation insider sources that my team and I use for my blog. And they are extremely sensitive about misinformation and speculation, so we knew that they wouldn't publish something like this without having good sources. Now, the fuel cutout switches are located on the central pedestal behind the two thrust levers, and we pilot normally manipulate them on the ground, either to start the engines before a flight or to shut them down after we stop at the gate. They are located where they are within easy reach of each of the pilots because they also form part of several important emergency checklists like engine fire, severe damage or separation for example, where we quickly might need to cut the fuel to the burning or damaged engine. Now, after that initial reporting from The Air Current, sure enough, the preliminary report did show that at time 0808 and 42 seconds, just three seconds after Air India Flight 171 had become airborne, the fuel cutout switches of first engine number one, then a second later, engine number two suddenly transitioned from run to cutoff.

Understanding the Fuel Cutout Switch Design and History

There are a couple of features designed in these switches to make sure that nobody can bump or move them accidentally. First, there are two big ears poking out of the pedestal on either side of the switches to shield them from any accidental bumping. And secondly, the switches themselves can't simply be flipped back and forth. No, to move them, you first need to pull upwards, then pivot the switch over into a new position and then release it into its new notch. This is a well-proven design. Other switches in Boeing cockpits work in very much the same way, like the landing gear lever for example, which also needs to be pulled out and then rotated and released. Now, I should mention that the preliminary report also highlights an FAA Special Airworthiness Information Bulletin, or SAIB, that was released back in 2018. That bulletin involved the locking feature of the fuel control switches like these, but ones that were installed on Boeing 737s. And the bulletin said that some of these switches were apparently installed with the locking feature disengaged or not up to standard. But that was, however, not considered an unsafe condition by the FAA, and even though an inspection of these switches was recommended, it was never made mandatory. The interim report states that Air India had not made this voluntary inspection of this particular aircraft, but it's important to point out here that there are no reports in the history of this aircraft showing any critical problems with these specific switches. On top of that, the report also points out that the fuel control module that includes these switches was replaced on this aircraft twice after this SAIB was issued, once in 2019 and again in 2023, for reasons that had nothing to do with the fuel control switches.

The Unanswered Question: Pilot Action or Malfunction?

Now, I really want to stress that at this point, we do not know how or why these switches were moved, but we know that one of the pilots did ask the other, why did he cut off? And the other pilot replied that he did not do so. Those statements will be the subject of a lot of scrutiny by the investigation going forward, but at the moment it can be interpreted in two different ways. One that the pilots did, in fact, not move the switches, but the other that one of them did but just didn't own up to it. In any case, the aircraft did as it was told. Fuel to the engines was immediately cut off, and the engines quickly started rolling back. And that obviously was what triggered the release of the Ram Air turbine in the back, which I mentioned earlier.

Final Seconds: Engine Relight Attempt and Impact

Then, at a time 0808 and 52 seconds, 10 seconds after the fuel control switches were moved to cut off, someone then moved the engine one switch back to run, and four seconds later also the switch for engine number two. At the same time, the aircraft automatically initiated the start of its auxiliary power unit, the APU, to give the aircraft some extra electrical power. But unlike the Ram Air turbine, which started supplying the aircraft with hydraulics just five seconds after it was deployed, the APU likely never had time to come online. However, some other systems in the 787 were working to save the aircraft and its passengers and crew. When the fuel cut-off switches are moved back to run and the plane is in flight, the engine electronics automatically attempt to relight the engines as soon as possible. So that was what now happened. The flight data recorder showed that the exhaust gas temperatures, or EGT, for both engines now started rising. Engine number one, whose switch was restored first, stopped its deceleration and started to recover. Engine number two was a bit slower, but in any case, by this point, it was already too late. 13 seconds after the first engine switch was moved to run, one of the pilots made a Mayday call, whose exact wording was not quoted in the report. And just another six seconds later, the aircraft hit the northeast wall of a nearby building with an estimated nose-up angle of about eight degrees. When it did so, it quickly disintegrated, with pieces of its fuselage, wings and engines subsequently hitting four more buildings around, and its enormous fuel load caught fire. All but one of the plane's 242 occupants, plus 19 people on the ground, lost their lives in the crash, and many more on the ground were seriously injured.

Looking Ahead: The Importance of the Final Report and Transparency

So where do we go from here then? Well, again, this is a preliminary investigation report, which is intended only as a factual account of what happened. We will know the full story when the final report is released, likely in a year or two from now. Until then, I would really recommend everyone to try to stay clear of speculation around the Boeing 787, Air India and everything else here, until the investigation comes with actionable safety actions to take, because only then can we be sure that all of the different angles have been taken into account. Now like I said in the beginning, the early information vacuum on this accident meant that people started looking in the most unlikely places for any type of information. Cabin entertainment system that doesn't work on the ground, or air conditioning systems that aren't running immediately after boarding can be really frustrating for sure, but these systems are often separate from what we pilot consider in the cockpit and what we need for a safe flight, and they seldom offer any clues about what caused an accident like this. Now when it comes to misinformation, there are a few clues to look for in order to see them. The very first hoax reports came within days of the crash, adding that a final report would be ready within a coming couple of days, and that would obviously be utterly impossible. So if you see reports like this, have a look at the dates and see if they make sense. Again, this is the worst aviation accident in the last decade, and attention on it could remain very high for weeks and months, and rightly so. Understandably, Boeing took this matter very seriously, effectively pulling out of the Paris Air Show in June to help assist the investigation in any way that they could. But here I should also point out that at least as we are writing this, we haven't heard Boeing releasing any safety bulletins or the FAA publishing any airworthiness directives on the Boeing 787, and there were also no such indications in the interim report. This suggests that even though the investigation is slowly focusing on specific systems, this accident is likely not related to a design problem with the aircraft. But that's where we need to draw the line between speculation and information. India's Aircraft Accident Investigation Bureau have support from the NTSB, the FAA and from Britain's Air Accident Investigation Branch, and by the way, this preliminary report was far more detailed than many had expected, which I am super, super happy to see. It is refreshing to see that kind of openness and transparency, which is exactly what we need in order to learn from tragedies like this.