Preliminary report...
Really, it'd be nice to have the FDR graphs & CVR transcript...

Some more information from that preliminary report.

It said one pilot could be heard on the cockpit voice recorder asking the other why he cut off the fuel.

"The other pilot responded that he did not do so," the report said.

And there is more information posted to the AvHerald source linked to in the earlier post, as below-

As per the EAFR data, the aircraft crossed the take-off decision speed V1 and achieved 153 kts IAS at 08:08:33 UTC. The Vr speed (155 kts) was achieved as per the EAFR at 08:08:35 UTC. The aircraft air/ground sensors transitioned to air mode, consistent with liftoff at 08:08:39 UTC.

The aircraft achieved the maximum recorded airspeed of 180 Knots IAS at about 08:08:42 UTC and immediately thereafter, the Engine 1 and Engine 2 fuel cutoff switches transitioned from RUN to CUTOFF position one after another with a time gap of 01 sec. The Engine N1 and N2 began to decrease from their take-off values as the fuel supply to the engines was cut off.

In the cockpit voice recording, one of the pilots is heard asking the other why did he cutoff. The other pilot responded that he did not do so.

As per the EAFR data both engines N2 values passed below minimum idle speed, and the RAT hydraulic pump began supplying hydraulic power at about 08:08:47 UTC.

As per the EAFR, the Engine 1 fuel cutoff switch transitioned from CUTOFF to RUN at about 08:08:52 UTC. The APU Inlet Door began opening at about 08:08:54 UTC, consistent with the APU Auto Start logic. Thereafter at 08:08:56 UTC the Engine 2 fuel cutoff switch also transitions from CUTOFF to RUN. When fuel control switches are moved from CUTOFF to RUN while the aircraft is inflight, each engines full authority dual engine control (FADEC) automatically manages a relight and thrust recovery sequence of ignition and fuel introduction.

The EGT was observed to be rising for both engines indicating relight. Engine 1’s core deceleration stopped, reversed and started to progress to recovery. Engine 2 was able to relight but could not arrest core speed deceleration and re-introduced fuel repeatedly to increase core speed acceleration and recovery. The EAFR recording stopped at 08:09:11 UTC

At about 08:09:05 UTC, one of the pilots transmitted “MAYDAY MAYDAY MAYDAY”.

Also from the AvHerald

On Jul 11th 2025 a reader made The Aviation Herald aware of a Service Bulletin released by General Electrics (the engine manufacturer) and the FAA: Service Bulletin FAA-2021-0273-0013 Attachment 2, which recommends the replacement of the MN4 microprocessor on ECU with respect to engine fuel and control stating: "This recommendation is to address a condition that may affect Flight Safety." The service bulletin further states: "Accumulated thermal cycles of the EEC with age causes the solder ball to fail."

A dry solder joint can result in fuel cut off??????????????

I would have hoped a fail safe design would be that the failure of the fuel on/off circuit would result in either
A -fail safe- the failure of the control circuit would result in the fuel continuing to flow. Yes, that would be bad if there were a fuel leak on the ground, or after an incident where you want to shut down the engines quickly. But better that than have a failure result in no fuel to the engines when in flight.
B -no change in status (ie if on, it stays on, if off it stays off).

That service bulletin is from 2021. Would it have applied to this particular aircraft? If so, was it not acted on?
Are Air India's past maintenance issues (and it would seem current ones as well) coming back to haunt them?

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Grant
Darwin NT

Went to PPRuNe to see if there was anything there relating to the latest news, unfortunately flight and maintenance crew are notable in their absence there at the moment.
From the wording of the preliminary report, everyone there has determined that the fuel switches were physically moved.

However, it's very probable that they weren't.


Given the number of switches, sensors & the like on an aircraft the size of the 787, there is no way that the FDR (Flight Data Recorder) can have a direct input from each and every one of those that it does actually monitor the parameters of.
The FDR gets it's input from the FDAU (Flight Data Aquisition Unit). And while it does get some of it's input directly from particular sensors or switches, much of it's input would be from intermediate devices.
And not having the slightest idea where the fuel switch position data comes from, my personal WAG (Wild Arse Guess) is that it comes from the FMS/FMC (Flight Mangement System / Flight Management Computer). The likelyhood of actually having the physical position of the switches directly monitored is next to zero IMHO.
So while moving the switches shows up as a change of position, so would anything that affects those inputs to the FMS/FMC- such as a loose plug, dry joint etc.


There have been many incidents where the CVR (Cockpit Voice Recorder) has recorded the sounds of the Stab trim (stabiliser trim) switches being used, matching up with what was shown on the FDR data. However, whether the fuel switches make enough noise to be heard over the sound the engines during take-off, i've no idea, but it's going to be of great importance to determine if they were physically moved or not.

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Grant
Darwin NT

https://www.youtube.com/watch?v=wA_UZeHZwSw
Buried in the report is a key fact, that Air India had not complied with a Special Air Worthiness Directive to test the switches to insure the locking mechanism on the switches was functional and they could not be inadvertently moved. As to some other part being at fault, the report indicating the switches were returned to the run position and the engines both responded likely rules that out. Also the comment from one pilot to the other asking why they moved the switches indicates that the switches were observed in the off position.

I'm beginning to think the blame belongs on senior management at Air India for cost cutting safety!

As to some other part being at fault, the report indicating the switches were returned to the run position and the engines both responded likely rules that out.

Maybe.
The switches may not have been physically moved at all- if the fault were a loose wire/faulty soldering joint, it would still show up in the FDR data as fuel on, fuel off, fuel on again.
And it seems odd that if the switches had been physically moved to off, why it did take an extra 4 seconds for the second engine to be switched on after the first one was?

Also the comment from one pilot to the other asking why they moved the switches indicates that the switches were observed in the off position.

Or the EICAS (Engine Indicating and Crew Alerting System) displayed a fuel off notification and so the pilot queried about the fuel switches being moved.
If observed in the off position, i'd have thought it would be a case of immediately moving them back to on by that observer. Even allowing for slow polling of the fuel switch data, 10 seconds is a long, long time to turning them back on if you had observed them off (even allowing for any delay due to surprise and the take-off workload) (we really need the CVR statements to have the time stamps with the dialogue).
I'm not saying it's not what happened, but i'm reluctant to go straight for a suicidal aircrew member when there are other very plausible options yet to be ruled out (and even if the physical lockouts were faulty/missing, it would still take intent to move those switches).

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Grant
Darwin NT

I'm not saying it's not what happened, but i'm reluctant to go straight for a suicidal aircrew member when there are other very plausible options yet to be ruled out (and even if the physical lockouts were faulty/missing, it would still take intent to move those switches).

As Juan points out someone should have had a hand immediately next to them guarding the thrust levers. It is not inconceivable that (wake) turbulence knocks that hand into the switches. After 12 years of flight operation it also isn't inconceivable that years of finger oil, lint, dust and food have built up making the latch mechanisms less effective, never mind someone cleaning up a spill and getting parts of a rag caught up or a carelessly placed charge cord for an ipad flight bag. Which would also explain the time difference getting the switches back to run as someone clears the gate to change it.

We may never get the CVR with timestamps as it may be sealed by prosecutors looking to murder charges.

With *NO* technical bulletins coming out, some kind of equipment failure does not seem likely.

I guess this is a good of a place for this.
Death by GPS: Study finds blindly following navigation can be fatal

A new study from researchers in the U.S. and Germany examines how blindly following GPS directions can lead to dangerous (and sometimes fatal) navigation errors.

...

The study identified 52 fatalities and a number of serious injuries, though more than half of the accidents didn’t result in a death.

Take the time to read the study summary (pdf) before setting off on your next journey with a navigation device.

Fireball erupts as small plane crashes at Southend airport


Incident reportedly involved a twin-engined Beechcraft King Air B200

Image from The Telegraph

BBC - Plane crashes at Southend Airport, says police

An aircraft has crashed at London Southend Airport, police have confirmed.

Essex Police said it was alerted to a 12-metre plane on fire at the site in Southend-on-Sea shortly before 16:00 BST on Sunday.

The East of England Ambulance Service said four crews are at the scene including a rapid response vehicle, a hazardous area response vehicle and a senior paramedic.

"It took off in probably three or four seconds. It started to bank heavily to its left."
"I said to my wife, that's unusual. We don't find aircraft normally turning at that stage in their ascent."

Why do I feel like "remove before flight" wasn't?

This can't be safe.. why 20 years on & still not fixed?? ACCIDENT WAITING TO HAPPEN
Train Brakes Can Be Hacked Over Radio—And the Industry Knew for 20 Years

CISA last week published an advisory describing CVE-2025-1727, an issue affecting the remote linking protocol used by systems known as End-of-Train and Head-of-Train.

An End-of-Train (EoT) device, also known as a Flashing Rear End Device (FRED), is placed at the end of a train, being designed to transmit data to a device in the locomotive named the Head-of-Train (HoT). The system, introduced to replace the caboose, is used to obtain status data from the end of the train (particularly useful for long freight trains), but it can also receive commands to apply the brakes at the rear of the train.

The problem, according to CISA’s advisory, is that the protocol remotely linking the EoT and HoT over radio signals is not secure (no authentication or encryption are used), enabling an attacker to use specially crafted packets transmitted with a software-defined radio to send commands to the EoT device.

https://www.youtube.com/watch?v=wA_UZeHZwSw
Buried in the report is a key fact, that Air India had not complied with a Special Air Worthiness Directive to test the switches to insure the locking mechanism on the switches was functional and they could not be inadvertently moved. [...]

I'm beginning to think the blame belongs on senior management at Air India for cost cutting safety!

A dry solder joint can result in fuel cut off??????????????

I would have hoped a fail safe design would be that the failure of the fuel on/off circuit would result in either
A -fail safe- the failure of the control circuit would result in the fuel continuing to flow. [...}
B -no change in status (ie if on, it stays on, if off it stays off).

That service bulletin is from 2021. Would it have applied to this particular aircraft? If so, was it not acted on?
Are Air India's past maintenance issues (and it would seem current ones as well) coming back to haunt them?

Crash: India B788 at Ahmedabad on Jun 12th 2025, lost height shortly after takeoff, no thrust reported (Update Jul 14_18:05Z)
wrote:

On Jul 12th 2025 (UTC) India's media report that the investigation is NOT focussing on a human action causing the fuel switches to appear in the CUTOFF position, but on a system failure. The Service Information Bulletin by the FAA issued in year 2018 recommending to upgrade the fuel switches on 737s and inspecting the fuel switch locking feature on other aircraft types including the Boeing 787 to prevent inadvertent flip of the switches, as well as the FAA/GE issued Service Bulletin FAA-2021-0273-0013 Attachment 2 relating to loss of control issue (also see above) were NOT implemented by Air India.

The stated MN4 computer with faulty soldering, that might weaken and lose contact due to the thermal stress after a number of cycles, interprets data and commands fuel metering valves - with the lost contact attaching the MN4 processor to the EEC intermittent electrical contact, loss of signal processing and engine control faults can occur. The SB writes under conditions for the SB: "An LOTC (Loss Of Thrust Control) event has occurred due to an EEC MN4 microprocessor solder ball failure." According to discussions in the industry it may be possible with the number of cycles VT-ANB had already completed, the solder balls were weakened sufficiently to detach the MN4 from the EEC momentarily due to loads during the takeoff rotation leading to the loss of control of thrust and shut down of the engines.

On Jul 14th 2025 India's DGCA instructed airlines to check the fuel switches on the Boeing 787 and Boeing 737 aircraft as used by Air India Group, Indigo and Spicejet for possible disengagement of the fuel control switch locking feature according to the SAIB released by the FAA on Dec 17th 2018. The checks have to be completed by Jul 21st 2025.

Who's the culprit?

Boeing? Air India senior management? Both?

THAT is one hell of a serious and deadly design flaw if a singular electrical connection failure can bring down the aircraft.


... However...

For this example, both switches were logged as being disengaged within the same one second...

Surely a near impossible coincidence...


There is a lot more to this story yet.

... Including the cockpit design, and common mode faults, for supposedly safely redundant safety critical systems...



Fly safe??
Martin

---

See new freedom: Mageia Linux
Take a look for yourself: Linux Format
The Future is what We all make IT (GPLv3)

Here is some very good thorough commentary about aircraft cockpit cameras:


Why Pilots DON'T Want THIS!


How do we stay safe from (the fear of) business and Management practices?...


Fly safe??
Martin

---

See new freedom: Mageia Linux
Take a look for yourself: Linux Format
The Future is what We all make IT (GPLv3)

On Jul 12th 2025 (UTC) India's media report that the investigation is NOT focussing[sic] on a human action causing the fuel switches to appear in the CUTOFF position, but on a system failure.

Having watched a video of the switches being operated on the ground, one thing stood out. After you change the position of the switch it appears as if you must push the switch downward (towards the switch body) to ensure the gate engages. It did not appear that if you simply let go that some spring would pull the switch into place. Now I'm sure there is a spring, but give several thousand cycles and it is anyone's guess if the spring still has the tension it should. Also any dirt at the bottom of the gate could easily prevent correct engagement. These are not "human action" but could be called "system failure."

As to solder balls each engine should have its own ball. Having both fail at nearly the same time might be possible, but not without many failing. That should be showing on the data recorder on other channels. Having both reconnect after failing is not likely. Hopefully they recover that circuit board however impact damage may make it impossible to gain information. X-ray and/or MRI.

People want it to be some sort of they never could have seen it coming event. That makes the lawyers salivate. If it is some kind of wear and tear issue, all the deep pockets go away and there is no meat left on the bones for the lawyers to feast on.

A unified timeline with the CVR and FDR data. Complete mechanical inspection reports. And very importantly the results of the ROK and India fleet inspection reports to see if there is a trend. Until these are in it is all smoke.

Having watched a video of the switches being operated on the ground, one thing stood out. After you change the position of the switch it appears as if you must push the switch downward (towards the switch body) to ensure the gate engages. It did not appear that if you simply let go that some spring would pull the switch into place. Now I'm sure there is a spring, but give several thousand cycles and it is anyone's guess if the spring still has the tension it should. Also any dirt at the bottom of the gate could easily prevent correct engagement. These are not "human action" but could be called "system failure."

For simple stuff like an USB plug, there's a technical specification that defines how many plug-in/unplug cycles it is designed for. If that limit is exceeded in a given usage scenario, it must be replaced timely. The number of times a B787's fuel cut-off switches are actuated should be fairly easy to estimate: age in years; typical operating days per year; number of flights per day. The durability of switches can be evaluated in a test lab. One would assume such switches are constructed sufficiently robust to last at least until the next D-check (six...ten years?) in short-haul operation. Additional wear due to dirt, dust, crumbs, and sand can be simulated in a lab at an accelerated time too.

I begin to assume there's a split responsibility for subpar robustness/durability of switches and computer boards (resp. soldering joints) on the part of Boeing and Air India's fleet maintenance pressed to minimize replacement costs.

As to solder balls each engine should have its own ball. Having both fail at nearly the same time might be possible, but not without many failing. That should be showing on the data recorder on other channels. Having both reconnect after failing is not likely. Hopefully they recover that circuit board however impact damage may make it impossible to gain information. X-ray and/or MRI.

It's called the "MN4 computer", elsewhere the "MN4 processor" with ball soldering... Is there a separate computer/processor for each engine's fuel switch? Are they placed spatially apart from each other or could mechanical stress (wear & tear) over a decade of use place the same strain on both?

No matter how this MN4 computer... fuel cutoff system system is designed, FAA as well as EASA have certified it.

People want it to be some sort of they never could have seen it coming event. That makes the lawyers salivate. If it is some kind of wear and tear issue, all the deep pockets go away and there is no meat left on the bones for the lawyers to feast on.

I thought there is the Warsaw Convention resp. the current Montreal Convention as stated on each IATA airlines' flight tickets which limit liabilities in case of incidents and even fatal accidents?

The saying: "On the high seas and in court, you're in God's hands" also applies to "on board of aircraft", isn't it?

Further detail is given by Mentour Pilot:


EVERYTHING We Know About The Air India Accident!


All very curiously strange...


I'm still very leery about how safety critical redundant systems have vulnerable switches located right next to each other AND in very busy parts of the cockpit...

Why not have such cut-offs safely located, out of the way, and clearly separated, on overhead panels with a clear divider panel between the A and B redundant systems?...

Note the recent Vilnius crash of a Boeing 737 (all lives lost) due to the pilots (innocently) mistakenly switching off ALL the hydraulic pumps, that were controlled by an identical pair of neighboring switches located right next to the intended pair of the totally innocuous de-ice control switches... (The cockpit is a minefield...?)


Deadly by design?

Fly safe??
Martin

---

See new freedom: Mageia Linux
Take a look for yourself: Linux Format
The Future is what We all make IT (GPLv3)

I'm still very leery about how safety critical redundant systems have vulnerable switches located right next to each other AND in very busy parts of the cockpit...

Exactly the same on Airbus!

I'm still very leery about how safety critical redundant systems have vulnerable switches located right next to each other AND in very busy parts of the cockpit...

Exactly the same on Airbus!

For what examples are you highlighting?


Fly safe?
Martin

---

See new freedom: Mageia Linux
Take a look for yourself: Linux Format
The Future is what We all make IT (GPLv3)

I'm still very leery about how safety critical redundant systems have vulnerable switches located right next to each other AND in very busy parts of the cockpit...

Exactly the same on Airbus!

For what examples are you highlighting?

Textron are different.
https://www.youtube.com/watch?v=CoTsvyA-bRw

I'm still very leery about how safety critical redundant systems have vulnerable switches located right next to each other AND in very busy parts of the cockpit...

Exactly the same on Airbus!

For what examples are you highlighting?

Textron are different.
https://www.youtube.com/watch?v=CoTsvyA-bRw

Thanks for that. Interesting.

So... Similar to Boeing for that Airbus example. There must be some historical practice for keeping that layout...

And then we have the Cessna example, which completely does away with those switch locations, which to my mind looks to be an inherently far safer design.


Fly safe?
Martin

---

See new freedom: Mageia Linux
Take a look for yourself: Linux Format
The Future is what We all make IT (GPLv3)

The fuel selector(s) on the smaller single & twin Cessna are pretty crude and all too easy to configure wrongly and have caused quite a few engine out events of varying severity. Even some of the early Cessna jets still pretty crude and error prone.
I really can't understand why such systems are still used when there are somple, robust systems that could be used on what might be described as"heritage" design new aircraft. Indeed some of the "new kid" designs do use them.

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Bob Smith
Member of Seti PIPPS (Pluto is a Planet Protest Society)
Somewhere in the (un)known Universe?