Air India 787 crashes on take off 2

• Wednesday at 10:56 AM

• Thread starter
• #101

LittleInch

Petroleum

Mar 27, 2013

22,890

GB

I've been on that page for a while now as well.

 

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• Yesterday at 4:06 PM

1
• #102

G

Garbage1

Civil/Environmental

Oct 31, 2024

201

I have read default position for Fuel Shutoff Valves (FSOVs) is the off position. Therefore complete loss of electrical power automatically shuts fuel off to both engines (perhaps spring loaded to auto close) RAT would take some time (say couple seconds) to deploy and provide power after deploying, and engines already shut down with no altitude/time to start back up.

They went on to say Airbus has battery backup power for fuel valves, but not 787.

 

Last edited: Yesterday at 4:42 PM

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• Yesterday at 11:09 PM

• Thread starter
• #103

LittleInch

Petroleum

Mar 27, 2013

22,890

GB

But what was the Original failure?

Ï I've seen that the badly burnt front unit was henning sent to NTSB in the UD as this might have data after the assumed dual engine shutdown.

 

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• Yesterday at 11:46 PM

• #104

G

Garbage1

Civil/Environmental

Oct 31, 2024

201

LittleInch said:

But what was the Original failure?

Ï I've seen that the badly burnt front unit was henning sent to NTSB in the UD as this might have data after the assumed dual engine shutdown.

Click to expand...

Don't know, perhaps once Captain Steve gets past his latest video on "Vapor Lock" we will find out........


In reading the following, u would expect main battery to be first backup to electical power loss, and you would think backup design would keep fuel valves open. Now did main battery also fail or did electrical failure take it out of loop?


The 787 Dreamliner has two primary rechargeable batteries – the main and auxiliary power unit (APU). While identical part numbers, they serve separate purposes.

The main battery “powers up” aircraft systems, bringing the airplane to life before the engines have been started. Once the engines are started, the electrical energy to run the systems comes from generators. It also is used to support ground operations such as refueling and powering the braking system when the airplane is towed. The main battery also provides backup power for critical systems during flight in the extremely unlikely event of a power failure. It is located in the forward electronics equipment (EE) bay, which is under the main cabin floor at the front of the airplane.

The APU battery supplies power to start the APU, which in turn can start the airplane engines. The APU, and its battery, also serves as part of the multiple layers of redundancy that would ensure power in the rare possibility of a loss of primary sources of power.

 

Last edited: Today at 12:20 AM

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• Today at 12:40 AM

• #105

TugboatEng

Marine/Ocean

Nov 1, 2015

11,992

US

I wonder what the replacement interval is for the batteries? The airframe age is right around the life expectancy of a lithium ion battery.

What is the response to a fire in the after electrical equipment bay?

 

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• Today at 4:47 PM

• #106

Alistair_Heaton

Mechanical

Nov 4, 2018

9,920

RO

Response is getting on ground asap.

Here is my valves which are open all the time normally.

 

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• 44 minutes ago

• #107

G

Garbage1

Civil/Environmental

Oct 31, 2024

201

Alistair_Heaton said:

Response is getting on ground asap.

Here is my valves which are open all the time normally.

Click to expand...

What response is getting on ground ASAP?

A legend would be helpful with the picture of the specific unknown airframe simulation, for folks without a pilot's license.......

I have added arrows to where I think you are referring to fuel shutoff valves for engines. No idea what some of the other symbols mean, or why there is green high-light is around the fuel tanks and the path to APU? While paths are white to engines?

 

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• 19 minutes ago

• #108

Alistair_Heaton

Mechanical

Nov 4, 2018

9,920

RO

Sorry was taken on phone at work.

It's an A220 on stand with the apu running just finished fueling to 7 tons

Engines are white because they are not running APU is green because it is. Green pipe means fuel flow. The green arrows mean fuel is going from the centre tank to the wing tanks.

The valves are white below the check box which indicates the fuel filters.

The response was about a fire in the avionics bay or electrical bay. We don't have a fire detector in there or fire suppression. It's part of the smoke emergency checklist which you progressively isolate different buses until the smoke clears. But it's a land immediately emergency checklist. ETOPs certified like the 787 may require to have a suppression system.

The emergency battery buses we can't see on a status page unless there is a problem.

 

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• 1 minute ago

• #109

G

Garbage1

Civil/Environmental

Oct 31, 2024

201

Thanks for the back ground information. You and Tug both bring up another possibility of a battery fire causing a power shut down process to start, whether automated or manual, and it is possible that shut down process could have caused momentary loss of power to fuel shutoff valves? If the fire source was due to a lithium ion battery short, then battery backup power is not available to handle transition from engine power generation to APU and/or RAT.

 

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