Air India Flight AI171 (Boeing 787-8) Crash

[wwillson]

Possibly. How many times have people claimed that they didn't intentionally step on the brake or didn't intentionally step on an accelerator? Or pressed the wrong button.

I get that it sounds strange, but this whole situation just seems so bizarre. I looks like the shutdown procedure is fairly simple even with the locking mechanism.

I would give your scenario a 0% chance of happening unintentionally.

 

[Cujet]

Are you referring to an alternate channel within the FADEC?

In essence, yes. Our Gulfstream's engines have a dual channel A+B setup. With 2 distinct circuit boards, two separate compartments in the same box. They have separate rows of connectors too, that are sized and configured to be 'idiot proof'.

In a simplified way, ours would use the A channel. Then switch to B channel when the engine RUN/OFF switch was cycled, such as at the end of a flight. Then back to A channel on the next switch cycle, and so on.

Channels A+B were always operational all the time. However, only the one in use would implement safety features. The unused channel used its own RPM sensors for example.

 

[MolaKule]

Here is an explanation of the fuel control switches excerpted from aeropeep:​

"Can the Control Switch Be Moved Accidentally?​

From a design and operational safety perspective, accidental movement of the fuel control switch is highly unlikely, due to several factors:

1. Physical Design:
   • The switch is guarded and requires deliberate manual action to change positions.
   • It has a firm detent mechanism that prevents casual movement due to turbulence or vibration.
2. Ergonomics and Location:
   • Located on the center pedestal, immediately behind the throttle levers, between the two pilots’ seats.
   • It is separate from frequently used flight controls and displays.
3. Procedural Controls:
   • Movement of the fuel control switch is governed by strict checklists (e.g., during engine start, shutdown, or emergencies).
   • Flight crew are trained to double-check its position and function during Pre-Flight, Before Start, and Shutdown checklists.
4. Electrical and Software Safeguards:
   • Even if the switch were somehow moved, the FADEC system requires multiple parameters to be satisfied before fuel is introduced.
   • Any anomaly or inconsistency will trigger ECAM or EICAS messages, alerting the crew immediately.

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Accidentally Moving Fuel Control Switch: Is It Possible in Flight?​

While the switch is mechanically moveable, inadvertent movement in flight is nearly impossible without deliberate human action. No known incidents on the B787 have involved unintentional activation of the fuel control switch. Any fuel starvation events are typically related to other causes, such as fuel system issues, maintenance error, or external factors—not accidental switch movement.

In the case of engine fire or severe malfunction, the crew may be instructed to use the switch as part of the emergency checklist. Even in these high-stress scenarios, pilots are trained to ensure correct and safe operation.

---

Conclusion​

The Boeing 787 fuel control switch is a critical part of the aircraft’s engine management and safety architecture. Its design prevents accidental movement, while integration with the FADEC and aircraft fire protection systems ensures fuel flow is tightly controlled and safe. With advanced safeguards and robust procedures, the Dreamliner ensures that critical components like the fuel control switch remain secure during all phases of flight."


https://aeropeep.com/boeing-787-fuel-control-switch-explained/

 

[dkryan]

According to an online article in the Wall Street Journal today (July 16th @ 7 p.m. EDT), the investigation has determined it was the captain who activated the fuel cutoff switches.

Apparently the CVR recorded the FO, who was flying, as asking the captain why he did that.

And apparently the captain denied having moved the fuel cutoff switches.

According to the article, the Air Accident Investigation Board (AAIB) in India is tightly controlling access to the entire transcript of the CVR.

However, an apparent leak from an investigative team member regarding the CVR transcript revealed the FO to be in panic mode after the switches were moved to “off.”

And the captain remained calm from the point of the switches being moved right up until the time of the crash.

As an aside, the Chairwoman of the U.S. NTSB asked to listen to the entire CVR recording but that has yet to happen.

 

[IndyFan]

Possibly. How many times have people claimed that they didn't intentionally step on the brake or didn't intentionally step on an accelerator? Or pressed the wrong button.

I get that it sounds strange, but this whole situation just seems so bizarre. I looks like the shutdown procedure is fairly simple even with the locking mechanism.

The brake pedal is in close proximity to the gas pedal. These things are not in a place where you are flipping switches to accelerate and climb out.