I've come by this.  It is a leaked early draft.

 

Flight: AI-171 | Aircraft: Boeing 787-8 | Route: Ahmedabad (VAAH) → London Gatwick (EGKK)
Crash Site: ~1.2 km from VAAH Runway 23, post-V1 and rotation
Fatalities: 247 (243 onboard + 4 ground)
Survivors: 1 onboard survivors (alternate to original), 3 injured on ground

🛠️  AAIB Preliminary Report Highlights

1.⁠ ⁠Primary Cause – Electrical Power Transfer Interruption (PTI) During Rotation
    •    During transition from ground to airborne electrical configuration, the aircraft experienced a cascading dual-engine FADEC (Full Authority Digital Engine Control) failure.
    •    Root cause: Uncommanded bus transfer failure due to arcing in the main power relay box (PRB-A), traced to water ingress during pre-flight GPU disconnection in heavy rain.
    •    This led to loss of electronic engine control at rotation, resulting in both GEnx engines rolling back to ground idle within 4–5 seconds.

2.⁠ ⁠Flight Data Record Timeline
    •    +0:11 sec: Nose gear lifts off.
    •    +0:13 sec: Sudden engine rollback begins. Thrust reduces from 92% N1 to <27% within 3 seconds.
    •    +0:16 sec: Master caution + ENG FAIL L/R warnings. FO calls, “Both engines dropping!”
    •    +0:20 sec: Autopilot and flight control reverts to Direct Mode. Pitch up attitude peaks at 18°.
    •    +0:25 sec: Aircraft stalls at 186 ft AGL.
    •    +0:30 sec: Full aerodynamic stall; nose drops rapidly.
    •    +0:38 sec: Ground impact at 54° nose-down attitude, 174 knots.

Contributing Factors
    •    Environmental Conditions:
    •    Torrential rain during pushback.
    •    Moisture intrusion into PRB-A connector (P/N: HLN8471) — a known corrosion-risk component.
    •    Latent Maintenance Issue:
    •    Power transfer relay unit showed signs of thermal damage in a previous MEL deferral 2 weeks prior.
    •    No replacement had been conducted; aircraft was cleared under repetitive deferral.
    •    Design Oversight:
    •    Boeing 787 has no physical engine control backup (i.e., no direct mechanical linkage in FADEC loss scenario).
    •    Loss of power supply to both EEC channels resulted in engine “freeze” at ground idle instead of flameout.
    •    Flight Crew Response:
    •    Attempted engine relight sequence not completed before stall onset.
    •    Emergency power selector not activated — possibly due to confusion from multiple ECAM warnings.
✈️  Immediate Safety Actions
    •    DGCA + EASA + FAA Emergency AD issued within 24 hours:
    •    Mandatory PRB-A moisture integrity inspection on all Boeing 787 aircraft.
    •    Temporary restriction on dispatch with MEL items related to power transfer systems.
    •    Boeing:
    •    Issued Service Bulletin SB-787-24-212 requiring replacement of PRB-A connectors with sealed versions.
    •    Exploring addition of dual-path power redundancy for FADEC systems.
 Lessons Learned
    •    Over-reliance on electrical power distribution architecture without layered redundancy.
•⁠  ⁠Lack of crew procedural training for full engine rollback during takeoff in EEC dual failure scenarios.
•⁠  ⁠Need for improved environmental sealing in GPU/electrical handover units in monsoon zones.
Human Toll
    •    The loss of 243 onboard lives, including 12 crew and 18 infants, deeply impacted the aviation community.
    •    Final words captured on CVR: “We lost everything – no thrust!”
    •    One family of five was killed on the ground in a hospital ambulance struck by debris.
Timeline – What’s Next?
    •    Aug 15, 2025: Release of FAA/Boeing electrical design audit report
    •    Sept 5, 2025: ICAO session on electrical-critical phase-of-flight risk mitigation
    •    Oct 2025: Mandated design retrofit across 787 fleet (rev. SB-787-24-219)

No mention of the Rat being deployed

44 minutes ago, Watawattana said:

•    Latent Maintenance Issue:
    •    Power transfer relay unit showed signs of thermal damage in a previous MEL deferral 2 weeks prior.
    •    No replacement had been conducted; aircraft was cleared under repetitive deferral.

This is the most damming section of this report. To save me rewriting it all, I'll copy/past the AI comment regarding an MEL.

 

'In aviation, a Minimum Equipment List (MEL) is a document that specifies the equipment, instruments, and systems that can be inoperative on an aircraft while still maintaining its airworthiness and allowing it to fly under specific conditions. Essentially, it outlines which equipment can be temporarily non-functional without compromising the safety of the flight'. 

 

In short, the aircraft was carrying a known fault. A fault that was to prove fatal!

 

With a failure like this @scubascuba3 the RAT would almost certainly have deployed. Not that it would have done them any good.

This is also a major issue ...

 

•    Boeing 787 has no physical engine control backup (i.e., no direct mechanical linkage in FADEC loss scenario).

 

So if the corroded connector gets wet due to heavy rain, and the engines roll back on rotation, there's no secondary system to keep the engines running.

 

That sounds like a serious design flaw by Boeing.  No redundancy in a safety critical system.

26 minutes ago, Moonlover said:

This is the most damming section of this report. To save me rewriting it all, I'll copy/past the AI comment regarding an MEL.

 

'In aviation, a Minimum Equipment List (MEL) is a document that specifies the equipment, instruments, and systems that can be inoperative on an aircraft while still maintaining its airworthiness and allowing it to fly under specific conditions. Essentially, it outlines which equipment can be temporarily non-functional without compromising the safety of the flight'. 

 

In short, the aircraft was carrying a known fault. A fault that was to prove fatal!

 

With a failure like this @scubascuba3 the RAT would almost certainly have deployed. Not that it would have done them any good.

 

Was it a fault, and did it prove fatal?

 

The relay "showed signs of thermal damage" does not indicate it was non-functional.  "Signs" could possibly be nothing more than a cosmetic blemish on the exterior of the unit.  Could have still been 100% functional.

 

Did this particular unit malfunction during the short flight, and if so, did it have any affect on the aircraft performance?

 

How many power transfer relay units are there on a 787?   Was this a critical component essential for safe operation, or a relay to supply power to the galley coffee machine when the engines are shut off?

19 minutes ago, Kinnock said:

This is also a major issue ...

 

•    Boeing 787 has no physical engine control backup (i.e., no direct mechanical linkage in FADEC loss scenario).

 

So if the corroded connector gets wet due to heavy rain, and the engines roll back on rotation, there's no secondary system to keep the engines running.

 

That sounds like a serious design flaw by Boeing.  No redundancy in a safety critical system.

Absolutely correct @Kinnock. I believe that the 787 is the first Boeing aircraft to go down the 'Fly by Wire' (FBW) route to flight control. Everything relying on electrical power. Airbus were way ahead on this. But I've always been a bit twitchy about this approach. All these systems are supposed to have 'triple redundancy', but I've often wondered, 'what happens if you loose all your power at a critical moment?'

 

Well, this is what happens!

 

15 minutes ago, NoDisplayName said:

 

Was it a fault, and did it prove fatal?

 

The relay "showed signs of thermal damage" does not indicate it was non-functional.  "Signs" could possibly be nothing more than a cosmetic blemish on the exterior of the unit.  Could have still been 100% functional.

 

Did this particular unit malfunction during the short flight, and if so, did it have any affect on the aircraft performance?

 

How many power transfer relay units are there on a 787?   Was this a critical component essential for safe operation, or a relay to supply power to the galley coffee machine when the engines are shut off?

The report said that is was 'a contributing factor'. They will know a lot more about that than you or I are likely to know.

1 hour ago, scubascuba3 said:

No mention of the Rat being deployed

I think you were marked down because most people never heard of the RAT, including me, till yesterday

Crikey! Fly by wire has always worried me in the case of emergencies. Still far safer nowadays of course (when everything is well maintained). 

Ita not a good day for the 787 or boeing, another has made an emergency landing. Hong kong possibly. but can't remember the details

Is this a genuine AAIB report?  It looks convincing, but there was a hoax AAIB report about a faulty pilot seat yesterday.

2 hours ago, Watawattana said:

I've come by this.  It is a leaked early draft.

 

Flight: AI-171 | Aircraft: Boeing 787-8 | Route: Ahmedabad (VAAH) → London Gatwick (EGKK)
Crash Site: ~1.2 km from VAAH Runway 23, post-V1 and rotation
Fatalities: 247 (243 onboard + 4 ground)
Survivors: 1 onboard survivors (alternate to original), 3 injured on ground

🛠️  AAIB Preliminary Report Highlights

1.⁠ ⁠Primary Cause – Electrical Power Transfer Interruption (PTI) During Rotation
    •    During transition from ground to airborne electrical configuration, the aircraft experienced a cascading dual-engine FADEC (Full Authority Digital Engine Control) failure.
    •    Root cause: Uncommanded bus transfer failure due to arcing in the main power relay box (PRB-A), traced to water ingress during pre-flight GPU disconnection in heavy rain.
    •    This led to loss of electronic engine control at rotation, resulting in both GEnx engines rolling back to ground idle within 4–5 seconds.

2.⁠ ⁠Flight Data Record Timeline
    •    +0:11 sec: Nose gear lifts off.
    •    +0:13 sec: Sudden engine rollback begins. Thrust reduces from 92% N1 to <27% within 3 seconds.
    •    +0:16 sec: Master caution + ENG FAIL L/R warnings. FO calls, “Both engines dropping!”
    •    +0:20 sec: Autopilot and flight control reverts to Direct Mode. Pitch up attitude peaks at 18°.
    •    +0:25 sec: Aircraft stalls at 186 ft AGL.
    •    +0:30 sec: Full aerodynamic stall; nose drops rapidly.
    •    +0:38 sec: Ground impact at 54° nose-down attitude, 174 knots.

Contributing Factors
    •    Environmental Conditions:
    •    Torrential rain during pushback.
    •    Moisture intrusion into PRB-A connector (P/N: HLN8471) — a known corrosion-risk component.
    •    Latent Maintenance Issue:
    •    Power transfer relay unit showed signs of thermal damage in a previous MEL deferral 2 weeks prior.
    •    No replacement had been conducted; aircraft was cleared under repetitive deferral.
    •    Design Oversight:
    •    Boeing 787 has no physical engine control backup (i.e., no direct mechanical linkage in FADEC loss scenario).
    •    Loss of power supply to both EEC channels resulted in engine “freeze” at ground idle instead of flameout.
    •    Flight Crew Response:
    •    Attempted engine relight sequence not completed before stall onset.
    •    Emergency power selector not activated — possibly due to confusion from multiple ECAM warnings.
✈️  Immediate Safety Actions
    •    DGCA + EASA + FAA Emergency AD issued within 24 hours:
    •    Mandatory PRB-A moisture integrity inspection on all Boeing 787 aircraft.
    •    Temporary restriction on dispatch with MEL items related to power transfer systems.
    •    Boeing:
    •    Issued Service Bulletin SB-787-24-212 requiring replacement of PRB-A connectors with sealed versions.
    •    Exploring addition of dual-path power redundancy for FADEC systems.
 Lessons Learned
    •    Over-reliance on electrical power distribution architecture without layered redundancy.
•⁠  ⁠Lack of crew procedural training for full engine rollback during takeoff in EEC dual failure scenarios.
•⁠  ⁠Need for improved environmental sealing in GPU/electrical handover units in monsoon zones.
Human Toll
    •    The loss of 243 onboard lives, including 12 crew and 18 infants, deeply impacted the aviation community.
    •    Final words captured on CVR: “We lost everything – no thrust!”
    •    One family of five was killed on the ground in a hospital ambulance struck by debris.
Timeline – What’s Next?
    •    Aug 15, 2025: Release of FAA/Boeing electrical design audit report
    •    Sept 5, 2025: ICAO session on electrical-critical phase-of-flight risk mitigation
    •    Oct 2025: Mandated design retrofit across 787 fleet (rev. SB-787-24-219)

Obviously written by ChatGPT. 

Can you share your source?

I am very sceptical that this would leak. And these two statements seem clearly wrong:

 +0:30 sec: Full aerodynamic stall; nose drops rapidly.
 +0:38 sec: Ground impact at 54° nose-down attitude, 174 knots.

The nose never goes down, and the aircraft clearly flares just before impact and the nose is very much pointed upwards all the way down until impact.

1 hour ago, Moonlover said:

Absolutely correct @Kinnock. I believe that the 787 is the first Boeing aircraft to go down the 'Fly by Wire' (FBW) route to flight control. Everything relying on electrical power. Airbus were way ahead on this. But I've always been a bit twitchy about this approach. All these systems are supposed to have 'triple redundancy', but I've often wondered, 'what happens if you loose all your power at a critical moment?'

 

Well, this is what happens!

 

That is what the Rat is for, so this is not supposed to happen.

3 hours ago, Watawattana said:

Contributing Factors
    •    Environmental Conditions:
    •    Torrential rain during pushback.

It was clear and very hot, dust flying everywhere at V1, reports of 38-42C. So this report is BS..

38 minutes ago, josephbloggs said:

Obviously written by ChatGPT. 

Can you share your source?

I am very sceptical that this would leak. And these two statements seem clearly wrong:

 +0:30 sec: Full aerodynamic stall; nose drops rapidly.
 +0:38 sec: Ground impact at 54° nose-down attitude, 174 knots.

The nose never goes down, and the aircraft clearly flares just before impact and the nose is very much pointed upwards all the way down until impact.

Also - this 'report' say "torrential rain during push back" but it wasn't raining?

 

I suspect it's been written using convincing looking terms from other reports.

I am no specialist but before buying the ticket, I check which aircraft is used. If it's a Boeing, for me, it's next. Sure that does limit choices but my life is worth it. Bye Bye Boeing. 

I have locked this topic as this leaked report is one of several fake internet hoaxes.
 

A quick look shows that the number of reported fatalities is wrong and it reports “Torrential rain during pushback”, on what was a hot and clear day.

 

The whole post seems to be taken from a unverified reddit post.

 

It is pointless to debate or develop conspiracy theories based on a false narrative.

 

Also no link was provided to even support this story.

 

If a credible and verified link is supplied I will reopen the topic.