The public sentiment is dominated by grief, anger, and a strong call for accountability following the tragic crash of Air India Flight 171. Criticism is aimed at both the misleading media coverage and systemic failures in aviation safety. Many commenters express heartbreak for the victims, demand thorough investigations, and highlight the urgency for reform in aviation safety standards to prevent future tragedies.

Air India

Indian Aviation Regulatory Authorities

Media

Well let's get right on a summary of what we know and what we don't. Hopefully this can serve as a quick-stop for all the high-points of known topics. Please add comments and recommend additions or corrections! I'll get to them as I can.

  
I am a mechanic but I am not type certified on the Boeing 787, this is all just knowledge collected through the wonderfully knowledgable contributors on the other two megathreads and a copy of the FCOM from Google and what limited information it has.


Last Update: 17JUN2025 7:15pm EST


An excellently written analysis of the accident is also available on r/aircrashinvestigation [over here](https://www.reddit.com/r/aircrashinvestigation/comments/1la62hn/air_india_flight_171_accident_analysis/).


# Official Reports and The 'Black Boxes'

* 241 out of 242 passengers and crew on board lost their lives in the crash, in addition to currently reported "at least" 38 people on the ground.
* The **Preliminary Report** will likely be the first summary of all the factual elements of the flight that we see, typically released within **30 days** of the accident
* Both of the black boxes are reported to have been recovered. It's reported that while many countries often send theirs to France or the US for reading, India now has their own laboratory with said capabilities, so they may be staying in-country
* [Thanks to u/MrFickless](https://www.reddit.com/r/aviation/comments/1ld9yb8/comment/my70hym/) While aircraft typically had two separate recorders, the Flight Data Recorder and the Cockpit Voice Recorder, documentation appears to show the 787 instead had two Enhanced Airborne Flight Recorders (EAFRs) instead, combined units that serves as both FDR and CVR, positioned in different locations in the aircraft for additional redundancy. The 'two recovered boxes' are likely just both EAFRs. At least 1 has a RIPS (Recorder Indepedent Power Supply) to power it for 10 minutes
* The Directorate General of Civil Aviation (DGCA) on Tuesday said surveillance conducted on Air India's Boeing 787 fleet did not reveal any major safety concerns. [...] The DGCA also said 24 of Air India's 33 Boeing 787 aircraft had completed an "enhanced safety inspection" it had ordered the airline to carry out [Thanks to u/Nyungwe23 for the [official link](https://www.pib.gov.in/PressReleasePage.aspx?PRID=2137035).] 



# Unofficial Reports

* A number of 'Preliminary Reports' have been circulating some media sites, including one stating the pilot's seat mechanism failed and he slid back and grabbed the throttles, complete with transcripts from a CVR that hasn't been opened yet (16JUN). Exercise critical thinking and appropriate suspicion of any such reports until they come from the AAIB or the NTSB
   * [Thanks to u/PunkAssBitch2000] The details of the alleged 'seat incident' calls similarities to [Air India Express 611](https://avherald.com/h?article=4bedd321), likely a source or inspiration for the write-up
* Reports of the crew's Mayday call consisting of anything other than 'Mayday' so far appear to be false, at least one apparent source of the extended 'losing power' call has since retracted their claim
* [From AvHerald, thanks to u/CATIIIDUAL] An alleged former Air India Captain apparently reporting the CVRs have been read out, "probably zero negligence in the cockpit", "preliminary report in a few days." The author of this edit is highly skeptical, but will record it here until further confirmation. [Comment Link](https://www.reddit.com/r/aviation/comments/1ld9yb8/comment/my8hjr2/)



# Elements of the Flight

* It appears with fair certainty the **Ram Air Turbine (RAT)** was deployed as it passed by the home of the teenager who caught the crash on video. There is no apparent sound of takeoff thrust accompanying the propeller-like noise of the RAT, which supplies some hydraulic and electrical power to the aircraft
* There is no system on board the 787 which prevents retraction of the flaps against the pilot's 'requested' position, only physical 'gates' to guard against inadvertent movement beyond certain positions \[see Tech Notes below\]
   * It appears at least the slats were deployed in bystander video. This is not explicit proof of flap deployment, as ONLY slats deploy at position 1 [Thanks to u/RandomObserver13]
   * Position 1 is the position of the upper flap handle 'gate' which prevents inadvertent full retraction of flaps AND slats above 1 from 5-20.
   * Any position except 5, 15 or 20 should generate a takeoff configuration warning at the beginning of the takeoff roll
* It appears retraction of the landing gear may have been initiated as the 'bogies' or 'trucks' appear (in bystander video) to be tilted forward, the first step of retraction
* Initial claims the aircraft took off with less than half the runway appears to be false based on incomplete flight tracking data, the aircraft backtracked to the start of the runway for a full takeoff run. Likewise claims it used excessive amounts of runway or kicked up additional dust than usual appear to be unfounded
* A lack of rudder input in the CCTV video of the takeoff appears to rule out an initial single-engine failure. That video also appears to rule out any visible evidence of a catastrophic bird strike
* The survivor reported a number of things, including a 'sudden application of thrust' which may be simply somatogravic illusion tied to the pilots pitching up, but he also reported the activation of 'white and green lights', which bears similarities to the Emergency Lighting system which would activate (briefly or permanently) on a loss of aircraft power



# Other Elements of Discussion/Concern/Query

* An ANA 787 had an unexpected dual engine shutdown after landing on January 17, 2019, activated by a system called the TCMA (Thrust Control Malfunction Accommodation), intended to shutdown runaway engines on the ground. Its logic should only activate it on the ground with weight on wheels if it senses the thrust lever is at idle but the engine is not
* The Airworthiness Directives relating to the potential loss of all AC power due to an aircraft being powered on for 248+ days (integer overflow causing GCU failsafe) should have been rectified under AD 2018-20-15 by the end of November of 2019. For those not in the know, Service Bulletins are optional. Airworthiness Directives are **mandatory**
   * Similar ADs relating to software bugs have occurred in other aircraft such as the A350, but pertaining to the 787 specifically include AD 2020-20-09 and AD 2020-06-14 [Thanks to u/throwaway-a0]
* Another AD relates to water leakage into the E&amp;E bay [details pending]




# Technical Notes

* Beyond manual deployment, the automatic deployment conditions of the Ram Air Turbine (RAT) include:
   * both engines have failed
   * all three hydraulic system pressures are low
   * loss of all electrical power to captain’s and first officer’s flight instruments
   * loss of all four EMPs (Electric Motor Pump, Hydraulic System) and faults in the flight control system occur on approach
   * loss of all four EMPs and an engine fails on takeoff or landing
* Circling back to the flap handle gates, [this video](https://www.youtube.com/shorts/q9voNK5Ss9k) shows them in action (though on the 737 which has different flap positions, the physical logic is the same)
* The Lithium-Ion batteries are now contained in a [stainless steel case](https://www.boeing.com/content/dam/boeing/boeingdotcom/commercial/airports/faqs/787batteryprocedures.pdf) with a vent overboard in the event of a thermal runaway
* The fuel supplied to the engines is powered by two AC pumps in EACH fuel tank. In the event of low pump pressure, the engines can draw fuel through a suction feed line that bypasses the pumps
* There are three separate hydraulic systems, Left, Center and Right. The Left and Right can be powered by Engine-Driven Pumps or Electric Motor Pumps. The Center is only driven by EMPs or the RAT
* Regarding Flight Envelope Protection (relating to the flap comments earlier), again, Boeing designs their systems different than Airbus and lets the pilot typically have the final say. The FCOM multiple times makes clear when speaking on these protection systems that they "do not reduce pilot control authority"

railker

[Flight Safety Detectives](https://youtu.be/nRJQj6pb9co?t=87) including former NTSB director Greg Feith put out an episode relating to the events so far. Particularly interesting was that he listed [10 different causes for a RAT to drop](https://youtu.be/nRJQj6pb9co?t=1481) (around 25:00), particularly that the 787's hydraulic pumps are electrically operated; and that disruption of the crash site could hinder investigation and evidence. But they're still waiting for the black boxes to get hard info.

Techhead7890

On Facebook in particular, there's been some fake news circulating about the existence of a preliminary report already by this date, as well as the probable cause being tied to the seat railing. As I mentioned, this is all untrue and is likely a product of an LLM given the syntax and use of emojis.

This hoax refers two completely made-up references: "Emergency AD 2025-16-51" and "Boeing Service Bulletin “787-25-123”. 

nguyenm

Would the recorders hold up through main power loss, before RAT? Does RAT power recorders as well?

Funkytadualexhaust

The only actual evidence we have at this stage is that the RAT was deployed, indicating a dual engine failure/stall. There was no power being generated by those engines. There is no jet noise in the videos. Only aerodynamic noise and that of the RAT.

Insaneclown271

Haven't had the chance to watch it yet, but Stig Aviation is a line mechanic and works on the 787 and has just put out a video showing some of the technical side of the things we've been talking about[ over here](https://www.youtube.com/watch?v=-MDjRMkc-cc).

  
Edit: Around **7:00** in, he starts getting into the deep-dive. And makes clear early in the video, don't expect speculation or guesswork. This is strictly getting into technical knowledge on the Boeing 787.

**Air India Flight 171 Preliminary Accident Analysis** 

Here's a summary of my analysis on the crash over from the / ACI sub, the update focuses on potential causes of the dual engine failure scenario, which is looking more likely right now. If anyone has more insights, interested to hear your opinions. See the previous post for more details and the images, etc

[https://www.reddit.com/r/aircrashinvestigation/comments/1la62hn/air\_india\_flight\_171\_accident\_analysis/](https://www.reddit.com/r/aircrashinvestigation/comments/1la62hn/air_india_flight_171_accident_analysis/)

More evidence which strongly indicates a dual engine failure/flameout. 

\- **The only survivor’s account in a more recent video (NDTV)**; He mentions that 5-10 seconds after liftoff that the plane seemed to be ‘stuck’ \[I think that is referring to the obvious deceleration as seen in the CCTV video which would be fully explained by a significant loss of thrust\]. Then he said that a bit later, ‘green and white’ lights came on \[if correct, this would likely be the emergency lighting system, especially as he was sat at the emergency exit row with the signs close to him\]. This fully tracks with a dual engine failure \[the emergency lighting which would be armed at that stage of flight. would automatically switch if you lose the normal electrical system\]. In this interview he does not mention the loud bang as reported earlier. The poor man is obviously in shock and I wish the media would give him some space.  

\- **The distinctive sound of the RAT**. There is a noise at the start of video 1 (on the versions with the original noise), which does not correspond to engine sound. This is almost certainly the RAT, based on another video of a 787 flying past with the RAT deployed. Based on the trigger conditions of the RAT, one or both engines and the electrical system would not have been working. 

\- **The landing gear retraction** (not considering the drag aspect, but the ability to even retract the gear). I think for a split second you can see the main gear starts to retract but then it stops, this is around the time that there is no longer positive climb. This would make sense in case of a dual engine failure and the switch to emergency systems means only a gravity gear extension would be possible (but no hydraulic power to actuate LG doors and retract the gear itself). As many have pointed out, the tilt of the gear is more evidence of interruption of the retraction sequence. 

The reports of what the pilot communication with ATC was exactly, I’m not convinced is from an accurate source. But the Mayday call alone as I said before, shows the crew were aware of a desperate situation on board. And in case of a dual engine failure, they wouldn’t have had the chance to do much at that stage.

airbusrules

I’m seeing a lot of people speculating that this tragedy could have been “caused” by a TCMA issue. It needs to be stated that even if we find that TCMA was somehow activated after takeoff, the TCMA would not be the cause but rather the outcome of a multitude of other causal failures.

As far as I know, the TCMA can *only* activate if it detects an uncommanded high thrust *and* the airplane is on the ground. This translates to the failure of two separate control paths:
1) A failure in the FADEC in misinterpreting engine thrust command. Per DAL-A this probability must be less than 10^-9 failures per flight hour.
2) A failure in the plane’s altitude and weight-on-wheels (WOW) logic. AFAIK TCMA logic is only supposed to activate only if at least one radar altimeter and one WOW sensor indicate that the plane is still on the ground; assuming both are DAL-B systems, the failure rate of this logic should be in the ballpark of 10^-14 to 10^-13. Note that the probability that the FADEC receives a perfect false positive through a random bit flip or flips is also virtually impossible without component failure as well since ARINC protocols have a built-in error checking mechanism.

All in all, the combined probability of failures in both control paths simultaneously happening and thereby causing a dual engine shutdown is impossibly small… in normal conditions. The part I’m not seeing mentioned in discussions about the TCMA theory is that TCMA activation almost guarantees that there is systemic gross negligence in Air India’s maintenance, and that the real root causes would take much longer to untangle.

Independent-Mix-5796

Was really incredible how many social media sleuths jumped onto the raised/ no flaps theory almost immediately. You can really tell who has watched a 787 take off and who hasn't..

ebs757

Per this interview with Air India chairman 

https://www.msn.com/en-in/money/topstories/air-india-chairman-n-chandrasekaran-offers-apology-says-jet-had-no-red-flags-new-engine-findings-due-in-30-days/ar-AA1GYiEZ

"But the fact that I know so far is this particular aircraft, this specific tail, AI-171 has a clean history. As for the engines, the right engine was a new engine put in March 2025. The left engine was last serviced in 2023 and due for its next maintenance check in December 2025. Both engine histories are clean"

And

“There were no red flags or maintenance issues,”

Video, reporting same, citing unknown sources
https://youtu.be/iL5LJXtK64Y?si=ZccTytG8lS1Kumq5

priyajeet

Looks like as of today, [EAFRs are reported](https://www.reuters.com/world/india/black-box-crashed-air-india-jet-still-india-ani-reports-2025-06-24/) to still be in India under examination by the AAIB until a decision is made on where to send them for analysis.

As per latest press release, the data has been successfully extracted in delhi lab itself 

https://www.pib.gov.in/PressReleseDetailm.aspx?PRID=2139785

Simbaa0110

Same plane taking off from Frankfurt
[https://youtu.be/hLnftY89ito?si=wfKjD7ZoP0a-Jlqa](https://youtu.be/hLnftY89ito?si=wfKjD7ZoP0a-Jlqa)

Not____007

The amount of people in this sub that are certain they know what went wrong is fucking insane

Objective-Muffin6842

[Avherald reports](https://avherald.com/h?article=528f27ec&amp;opt=0):

&gt; 
On Jun 17th 2025 an official, a former Air India Captain trained by the Captain of the accident flight, stated, that the CVR has been successfully read out, the voices on the CVR are very clear. It is becoming gradually clear from the newly emerging evidence that there was probably zero negligence in the cockpit, the crew did not give up until the very last moment. The probability of a technical cause is high. A preliminary report by India's AAIB can be expected in a few days.

RX142

That guy Steve on YouTube is certainly milking this and making $$$. IMO he's the worst, using tragedy for his own gains.

He first blamed the pilots and put out video and sent on numerous shows and news media, acting like an expert, completely dismissing all other evidence and blaming the pilots.

He got backlash from informed people, in comments here and online, so he then makes another video 2 days later claiming 'new information about RAT' which is of course complete nonsense as people were posting about RAT from the beginning. Again, he gets to go on all the shows and get paid as an expert, not even apologizing.

ECrispy

I’m curious - what data is still recorded to the EAFR when the RAT is deployed?

Lyuseefur

If anyone likes maps and 3d, here's a Mymap with the CCTV location, photo triangulation of the takeoff and crash site. [https://www.google.com/maps/d/u/0/edit?mid=1lSA1-PTE9SLKYJRjKfyS8A0EQPXnmIo&amp;usp=sharing](https://www.google.com/maps/d/u/0/edit?mid=1lSA1-PTE9SLKYJRjKfyS8A0EQPXnmIo&amp;usp=sharing)

Would be interesting to further estimate the camera and building heights to get a rough altitude in addition to the lateral movement/speed.

Jamalala

One part I’m still wondering is the claims of the landing gear being tilted due to a gear up command that did not complete. 

If the gear had started to ascend and then the plane lost central hydraulic power due to damage to the electrically powered central hydraulic system it seems like that could explain the sequence of events we’ve seen. 

If the gear were tilted for another reason then it wouldn’t mean much. I don’t think gear staying down means anything in this instance obviously the crew had bigger problems.

The only other remote possibility would be a sequence of commands from the cockpit that are so egregiously bad they would almost have to be malicious.

DrSpaceman575

The survivor said that, green and white lights came on. Is the colour of lights or them coming on in any way significant or give any specifics?

Few-Media6255

Is there a typical timeframe for a preliminary report or is mostly case by case basis? I heard one of the aviation news sites suspected it would come out in the next few days but I cant find it anymore.

WorthDues

Fucking hell, captain steve released another AI171 video. He’s really milking this tragedy for views huh

FutureHoo

New here but just wanted to say this tragedy is truly awful. I’ve been thinking about this quite frequently. Almost 300 souls lost yet social media is filled to the brim with grifters exploiting this event like there’s no tomorrow. 

From people making inappropriate comments about the deceased, to deceitful AI videos to farm engagement. The nonsense speculation from ‘experts’, when we really don’t know anything until the reports are out. It achieves us nothing. 

I just can’t imagine what the passengers must’ve felt. May they rest in peace

theOJgotSqueezed

As a PIC on the A320s I have already experienced Thrust Control Malfunction due to a faulty engine probe (on ground). 

My theory is that this happened on both engines probes while the wheels sensors were still signaling “on ground” maybe just before V1 or at V1. 

And the residual thrust from the fans spinning might have given them the few seconds of flight time. 

This is compounded by the somotogravic illusion which the survivor noticed just after liftoff. 

I fly often into AMD and this time of the year there is a ton of visible dust or particles, common for AMD in summer where round airborne seed-like pods are prevalent. Maybe this clogged up the engine probes and sensors? 

I remember GEnx used to be notorious for sensor blockage and thrust rolling back especially with ice crystals.

AlphaPapaCharlie

The latest from a BBC report - "Air India says one engine on crashed plane was new"

Source - [https://www.bbc.com/news/articles/clyl636ynzvo](https://www.bbc.com/news/articles/clyl636ynzvo)

thefreeman06

Earlier today, a news channel reported that the black boxes will be sent to the US for data extraction. Turns out that was fake news according to Reuters, India still hasn’t decided where to sent them to. 

Link: https://www.reuters.com/world/india/india-send-crashed-planes-black-box-us-local-newspaper-economic-times-reports-2025-06-19/

Brief-Visit-8857

Possibly a stupid question, currently my thinking would be some catastrophic electrical failure.

I see a lot of different components, electrical systems, data recorders etc have independent and redundant power supplies. I'm just wondering how that is done? Cause I imagine if you go follow the chain high enough to the power source if there was a massive failure it could take a whole lot of systems out?

There's so much inbuilt redundancy it's hard to imagine how both engines lost power so quickly into the flight

pehpehsha2

Posted this in megathread 2 but still baffled. Has anyone seen any drone shots of the wreckage from above yet? I've only seen various angles from ground and building.. Hard to get an idea of how everything landed. Did the front of the fuselage end up at ground level even though the plane crashed into the 6th floor? 

Comment from mt2:
The thing I can't wrap my head around is this survivor. Sure he was in front of the wing / engines. But did the fuselage separate, his section was launched forward? Was he riding this thing till it stopped and jumped out? (sounds like the case) vs. catapulted out while it impacted. That explosion was so huge, I just can't imagine how he was so close and walked away. Baffling.. It would be interesting to see the crash site from above to get a better idea of where all the pieces landed..

Bramrod

Found a comment on YouTube, could be possible, take it with a grain of salt:

&gt; I believe the cause was a combination of Fuel Shutoff Valve (FSOV) activation due to a cascading electrical system failure. It's not the first time a 787 has experienced electrical cascade system failure during the first minutes in flight and required RAT deployment. Let me explain my reasoning:
On the Boeing 787, the engines will keep running even if all hydraulic systems fail. Each engine has its own FADEC (Full Authority Digital Engine Control), powered by a Permanent Magnet Alternator (PMA) that's driven by the engine itself. Once the engine is spinning, the FADEC operates independently - controlling fuel, thrust, and safety - with no need for aircraft hydraulics or external electrical power. A simultaneous FADEC failure is extremely unlikely.
So, why did the engines shut down if they are supposed to be so resilient? There is one important component that can override the FADEC: the FSOV.
This spring-loaded fuel shutoff valve is not powered by the PMA, but instead by the aircraft's electrical DC system. If power is lost, the spring closes the valve instantly, cutting off fuel to the engine. FSOVs are a fail-safe, designed to protect the airframe, not the engine. In Boeing's logic, it's safer for the engine to shut down than to keep feeding fuel into a potential fire.
In the video footage, the truck tilt actuator is in the forward position (toes down). This movement requires a hydraulic system force to overcome the wind and gravity. This forward position only happens when the landing gear retracted sequence is initiated by the pilots. The strange thing is that it is only the second step of the main gear retraction sequence to tilt the wheel truck forward. The first step is to open the doors, and if the doors are fully open, the next step is to tilt the wheel truck. It's unclear why the doors are closed but the truck already tilted forward.
Most likely the pilot selected "gear up," which triggered the retraction sequence. The truck tilt was initiated as step 2, but the doors didn't open due to power or hydraulic failure, or the sequence froze mid-process. The aircraft lost main power (hence the RAT), and the sequence halted with the gear in a partially commanded state: truck tilted, doors closed, gear extended.
That gear retraction moment may have been the exact point when the whole system collapsed just 3-4 seconds after takeoff. (there was a positive climb rate at 600ft AMSL and 174kt) The engines kept running briefly (seconds), powered by the remaining fuel in the lines before flaming out.
The main landing gear hydraulics are powered by an electric-hydraulic system — if there's no electricity, there's no hydraulic pressure. In contrast, other hydraulic systems on the aircraft are supplied by engine-driven mechanical pumps. (20-30kw power needed to retract gear)
Since the aircraft remained stable in flight, it's likely that both engines flamed out simultaneously. Flaps, fly-by-wire, landing gear, and other systems likely froze for a moment and possibly regained functionality after the RAT deployed. The +-15KW RAT powers the electric motors on the blue hydraulic lines of a 787.
This controls the key flight-control actuators for the rudder, elevators, and primary ailerons. It appears that the pilot slightly increased the nose attitude during the final phase of the flight. (landing gear retraction is not possible with a RAT)
For both FSOVs to close, the aircraft would have to lose both AC buses, both DC essential buses, and the battery backups. That requires a massive electrical failure to overcome all possible redundancy layers.
This is a possibility because there are known cases where a 787 and a 777 experienced a total electrical cascading failure of most systems. So it is possible.
All signs point to fuel cutoff via the FSOVs. The big question is why did they fail? This is hard to say but as said electrical failure is a very plausible cause.
The RAT was automatically deployed. This means there is a total loss of AC electrical power.
I suspect a scenario where a partially working or unstable electrical system triggers RAT deployment amid a power transition event. This could escalate into a full-blown electrical disruption, possibly interfering with the DC essential buses and battery backup. When switching power sources (from main buses to RAT), the system can behave unpredictably - especially if one source is competing with the RAT or is unstable.
In such a power chaos, RAT deployment might introduce transients or delays in power restoration, which could make power delivery unstable and possibly affect the digital managed power to the FSOVs. If they lose power, all fuel will be cut off.
On the 787, FSOVs don't have guaranteed dedicated or hot battery backup, unlike the Airbus A320, which powers them directly from the battery. The 787's battery backup supports the entire DC bus, and power management software prioritizes flight-critical systems. If power is limited or loads are erratic, less critical systems like FSOVs can be deprioritized. This is a very complex system with a lot of software rules.
This also reflects Boeing's design philosophy: in a severe power failure, airframe survivability and flight control take precedence over engine continuity. Their assumption is that it's safer to shut off fuel than risk uncontrolled flow in to an engine on fire.
The whole idea of the posibility of losing both engines at 400 ft during takeoff feels inherently unsafe. From a thrust continuity perspective, this design approach is a vulnerability and may have played a role in Flight Al171's dual-engine flameout.
To date, there are no documented cases of a modern Boeing experiencing a engine flameout from FSOV closure due to an electrical glitch. The 787 and other Boeing models have a history of similar electrical issues.
In 2024 an Atlantic Boeing 787 flight, VS105 during climb-out, the crew experienced a major electrical failure— engine generators dropped off-line. In response, the RAT automatically deployed to provide emergency power. In 2015, Boeing and the FAA discovered a critical software bug in the 787's Generator Control Units (GCUs). If left powered for 248 consecutive days, an internal counter could overflow — shutting down all four GCUs and cutting AC power entirely. The FAA issued Emergency AD 2015-08-51, requiring operators to reboot 787s every 8 months to avoid in-flight total power loss.
Two separate incidents-in Boston (JAL) ano
Takomatsu (ANA)-involved battery overheating and fire in the aircraft's APU lithium-ion batteries
In December 2018, LATAM Flight LA8084, a Boeing 777-300ER, suffered a complete electrical meltdown en route from São Paulo to London. The RAT deployed to provide emergency power. Once the engines were shut down on the ground, power suddenly returned - confirming a fault in the electrical distribution system (likely a bus contactor or converter failure). The event was a textbook cascading failure: generator power was available, but a chain reaction of breaker and converter failures disconnected all major buses, including those powered by the APU and engines.
The 787 relies heavily on software-based power management, so if the root cause turns out to be a software flaw in a extremely complex electrical system, the entire fleet could soon be grounded pending investigation.

I have a sinking feeling that this is going to turn into another massive scandal for Boeing. There just aren’t that many things that can cause a complete power loss within seconds, and all of the physical or mechanical explanations don’t seem to fit the facts here.

k_dubious

I haven't checked back on this in a few days...but did any other videos of the crash from people in the city ever surface? Do we only just have that CCTV video and the other video of the crash from that guy in the city? surprised we don't have any more. In the Brazil crash within a year ago there were so many more by bystanders.

Delicious_Novel_4400

Blythyvxr

https://www.reuters.com/sustainability/boards-policy-regulation/india-regulator-asks-air-india-training-data-pilots-dispatcher-crashed-plane-2025-06-17/

Indian regulators have asked Air India to submit training data for both pilots and also information on the dispatcher of the aircraft before Monday.

777978Xops

The amount of people falling for the emoji-ridden "report" is just disappointing. This is ChatGPT being about as obvious as it can, not trying to imitate professional writing.

Robo1p

1. AI171 accelerates with take-off thrust set
2. Just after V 1 the throttle-lever sensor fails and drops to 0 V, so the computer thinks the levers are at idle.
3. ~0.3s later, the TCMA sees that:
- Allowed-power line has slid downward far enough that the engines (still near full thrust) is above it.
- The aircraft is in fact still on the ground as it has not rotated
4. All conditions are met and TCMA shuts off fuel to both engines.
5. Even if the pilots are getting warnings, they are passed v1 and still committed to continue.
6. AI171 lifts off while running on fumes, and after a few seconds both engines flame out.

entrep

I know it was very short flight but at any moment after the stall when the plane was coming down if the engines came back to full power was there any chance of lifting the plane or the crash was inevitable?

AeBlueSadi

So, I found a comment that says the FSOV valves are ball valves, not spring loaded. Here’s the comment, take it with a grain of salt (again):

&gt; I don't think the cause was the powering off the fuel control valves, at least not the ones in the wing spar feeding the pylon/engine. 20-year aircraft maintenance electrical guy here (I posted on Captain Steeves engine failure video). The 787 engine fuel shutoff valves in the wing spars are motor actuated ball valves. It takes power to move them from open and power to move them to closed. This is the failsafe (the fact that they need to be powered to be able to both open and close) They are not spring loaded to close with power off. They will remain in their last position.
There is another fuel shutoff valve on each engine that is called the high-pressure shutoff valve (HPSOV) located in the Fuel Metering Unit (FMU) on the engine, and this valve is also closed via the fuel control switch or engine fire cutoff switch. It works a bit different obviously and is controlled by the Electronic Engine Control (EEC) which is powered by the permanent magnet alternator (PMA) on the engine. These are all part of the self-contained FADEC (Full Authority Digital Electronic Control) system. During the incident of the 787 that landed and both engines shutdown upon thrust reverser operation, it is the EEC that no doubt shut down the engines via the HPSOV as it will shut down the engine under certain parameters such as overspeed while operating in the "normal" mode. The EEC does "talk" to the rest of the aircraft via common data network and it is software controlled. Overall, I too also think this was an aircraft electrical system failure of some sort (unknown cause) that had unforeseen consequences that triggered and affected engine thrust and/or somehow triggered the same dual engine shutdown as in the 2019 incident you mentioned. The fact that the RAT deployed seemingly upon the weight off wheels (it cannot deploy until the aircraft is airborne) triggered some kind of fault that both EEC's interpreted the same way and either metered the engines to low power or shut them down completely. I tend to think they were metered down because the pilot did not indicate he lost both engines, just that he lost thrust power (I assume, as I haven't heard the radio call).
What was the system-wide electrical failure to begin with if that's the case? This is a mystery. The 787 is the most complicated "all electric" (and really the only one) aircraft out there. With millions of line of code, this may be another 2-3-year investigation. I just wish they would update us with at least what they know...

I have a theory. I’ve been studying the systems of the 787 and i think this is most probable paired with all available evidence. I do not want to claim this is *definitely* what happened but I welcome discussion. Feel free to correct me on anything.

The 787 has two main electrical generators, one on each engine called Integrated Drive Generators. These power the whole aircraft in flight. Now, if one fails, the other one takes over. But if both fail, or if their gearbox breaks, you lose both of your main AC Buses. Now, according to the theory paired with all the evidence, before takeoff, one generator was probably already offline and that would most likely be the left side IFEs being dead, the left packs not running, and flickering lights. In pre crash footage on the flight prior to the one that landed in Ahmedabad you could see one side of PSU cabin lights off and that means the left IDG or Ledt AC bus was already out. So, on the flight that crashed, the second generator failed duringn or just after rotation and so both AC buses dropped simultaneously. This is why that theory fits. The problem is, when both engine generators fail and the RAT kicks in, the FADECs don’t get normal power anymore. As a safety feature, they instantly roll the engines back to flight idle to protect them. The survivor said they heard a loud bang and saw the lights flicker and that lines up exactly with the moment the generator failed and the RAT deployed.

I would also like to clarify on the FADEC protection logic. FADEC protection logic on the 787 prioritizes engine integrity under unstable electrical conditions. In a situation where both IDGs fail with RAT deployment, if FADEC detects unstable power input from PMA or transitional RAT power, it immediately commands both engines to flight idle as a protective measure. This will ensure engine survivability but removes climb thrust authority until stable power returns. FADECs are designed to monitor power stability. If PMA voltage/frequency is out of tolerance and backup AC Bus power is lost or unstable during RAT deployment then the FADEC logic is designed to command rollback to idle to protect against surge, flameout or overspeed.

Edit: update, I believe the FADEC had commanded the HPSOV valve to close, rather than doing a protective rollback to idle. The HPSOV valve closes shut when losing power, however it is powered by the engine PMAs and therefore could not have been the issue. Rather. My theory of the FADEC protecting the engines is still very possible and had probably commanded the HPSOV valves to shut off. The FSOV has nothing to do with this as it will keep its last position when losing power. It could be a software glitch, or instability in the engine during transitional power.

HungaryCool

[deleted]

geology_person

I have a question I don't know much about it. The recent technical and fatal failures in boeing planes across the globe what about the question on maintenance from the airlines. Are those airlines actively maintaining and making necessary repairs to the planes??? Because there are airlines like Emirates qatar airways we barely hear boeing crashing there because they have record of good maintenance of aircrafts. I don't know much about aviation so looking for genuine response on this data please correct me if I'm wrong thank you

Pr1stine69

Dual engine failure but what caused that?

Totsuka1999

BrockStar-916

makeup-guy-852853

At the start of the video it seems it was descending. Then tried to pull up but can't. Can hear the engine though. And no smoke. Gear still down.

Is the air thin around those parts?

Some cargo came lose and altered the balance?

Ancient_Sea7256

ROOSTERyouDOWN

Silent_fart_smell

It was more like 32 seconds after takeoff.

Known-Bowl-7732

Now everyone knows that 11A is the survival seat. Prices for that seat going to increase 100x lol

verhovniPan

BigDikEnergy321

LeftcelInflitrator

theimpartialobserver

When the plane drops out of view and just before the plane exploded, I see a large piece of the plane fluttering above it. The surviving passenger said there was an explosion so I wonder if an engine blew up to make the large object I saw? Does anyone else see it?

BrierBob

[https://youtu.be/z7EZkungFEE?si=jkV4C4oilorE8cCR&amp;t=543](https://youtu.be/z7EZkungFEE?si=jkV4C4oilorE8cCR&amp;t=543)

this looks like the best explaination yet.

niyupower

That was not 5 mins - it was crashing from the instant it took off and was sinking the moment it was out of ground effect

angusalba

God bless all of them and give them a peaceful return to the Light. 🤍

as for their families, numb their suffering and fill their hearts with love. peace peace peace calm

LowerChipmunk2835

When you are making an emergency landing like that you would typically dump as much fuel as possible if you don't the wings will be too heavy for the landing force and then boom.

ThePervyGeek90

Wild how someone survived this. I wish more survived. Rest in peace.

cconnorss

Why you wanna put that out here? 242 souls perished. Tell you what, I’ll wait for your video mmm’kay?

Oedipus____Wrecks

Boeing bot accounts running interference in the comment section

The_Stereoskopian

Just gonna leave this here for all those nincompoops believing this was a manufacturing problem.

https://www.reddit.com/r/ahmedabad/s/EDZgzQRPxn

hunterxy

At 00:21, there are “dark lines” near the trailing edges on both wings, which might be due to extended flaps.

beaded_lion59

Sharp-Guest4696

Wow. That plane had barely any forward momentum when it came down.

DeathrayToaster

Honestly how did the sole survivor made it.... I wonder which part in the picture did he ended up after the crash

ZeneticX

The photos of the tail are from the building on the left, correct? Just trying to get a bit of perspective of the site.

teapots_at_ten_paces

Fire + carbon fiber really doesn't leave much behind does it!

Dear_Durian4088

Is that the plane on top of the building on the far left?

Very interesting that most of the fire damage is on the buildings on the right and the ground in front in between them.

ByteWrangler

NatGau

MasterMarik

Which direction is the airport from here? Is it to the left, so the airplane would have been going across in front of these buildings?

JoyousMN_2024

In the few seconds left, I wonder whether the pilot tried to steer towards open space or sparsely populated terrain to minimize ground impact.

nomad_ivc

RepresentativeLeg897

Winter-Ad-3826

He should have come out at the time of the first impact. The first impact should be the tail of the plane hitting the two-story building. When the plane almost passed the two-story building, the fuel leaked and caught fire, and spread to the four multi-story dormitories in front.

Extension-Cream6574

I was searching for such a picture to understand the trajectory of the crash.

So deep left is where the tail section is embedded into the building &amp; then the remaining plane continues to crash along the four buildings we see here.

God forbid had the plane be travelling at the typical takeoff speed or much higher, the devastation &amp; loss of lives would've been much higher.

UnlikeUday

Why didn’t those buildings all collapse into their own footprint at free-fall speeds? While also disintegrating as they fell? Weird!

If only Indians designed the Twin Towers and the Pentagon budget office that was hit!

G91_

Life certainly isn't fucking fair, man...


RIP

Phoenix2211

Mamba-0824

Kids! Little kids 🥺 That is just.. no.

Ohshithereiamagain

May they rest in peace. 

"We live and we die. We control nothing beyond that" -Mariko Sama

Own-Philosophy-5356

For my own mental health I will choose to believe you and this is AI generated. 

JFC rip.

ewizzle

Great message though. Just live now. Do it now. No waiting.

goobly_goo

The Air India Flight 171 crash resulted in significant casualties and extensive investigations to determine accountability.

Air India Flight 171 Crash

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