BA777 Fire KLAS

[Evan]

Qantas done the very same thing. Many people think it was to preserve there statistic of no hull losses. See the below link

https://en.wikipedia.org/wiki/Qantas_Flight_1

What a trainwreck. I wonder if they also managed to fix the captain and return him to service.

[VH-ROB]

Looks like BA decided to repair it(!!)

http://www.reviewjournal.com/business/british-airways-jet-caught-fire-takeoff-mccarran-fly-again

I've don't ever recall an airline repairing a plane damaged to this extent! Especially a 17 year old one.

Qantas done the very same thing. Many people think it was to preserve there statistic of no hull losses. See the below link

https://en.wikipedia.org/wiki/Qantas_Flight_1

[hongmng]

Looks like BA decided to repair it(!!)

http://www.reviewjournal.com/business/british-airways-jet-caught-fire-takeoff-mccarran-fly-again

I've don't ever recall an airline repairing a plane damaged to this extent! Especially a 17 year old one.

[ATLcrew]

That's pretty universal basic logic. If you are seeing discharge lights (and messages if you have EICAS/ECAM) and you haven't turned the fire handle, that's most likely a thermal discharge. But, as I said, they are placed far away from the nozzles/initial source of heat.

So, the answer is no, you DON'T have a 777 QRH?

[snydersnapshots]

So squib is the term you use to look cool on the aviation forum while solenoid is generic, but makes you look like a layman?

Squib and solenoid are two different devices. The squib is an explosive device, while the solenoid is mechanical. That being said, he probably should have made a comment explaining what a squib is in the post.

Here's a link to a Youtube video of a 737 fire extinguisher squib being fired. Really the only two points you need to see are the first 5 seconds and from 1:49 to 1:52 or so. Let's just say that video editing isn't the video poster's strong point.

[Evan]

Do you have the QRH of all airliners or what?

That's pretty universal basic logic. If you are seeing discharge lights (and messages if you have EICAS/ECAM) and you haven't turned the fire handle, that's most likely a thermal discharge. But, as I said, they are placed far away from the nozzles/initial source of heat.

[Evan]

From AvHerald:

On Oct 6th 2015 the NTSB reported that first examination of the engine revealed that the stage 8-10 spool in the high pressure compressor (HPC) had failed liberating fragments that breached the engine case and cowling. Additional pieces of the HPC were found inside the engine and sent for metallurgic examination. The fracture began in the stage 8 disk web.

That's the same section as the engines affected by the existing AD. GE has already said this engine had parts not affected by the AD, but maybe that AD needs to be expanded...

[3WE]

Do you have the QRH of all airliners or what?

And plenty of time to reference them at 0 kts and FL 0.5 without an active "engine" fire.

[Gabriel]

The bottles are housed in the fuselage, not near the engines (and opposite the #1 side) so thermal venting due to a fire would not occur until the heat from the fire reached that area. In that case you would get DISCH 1 and 2 lights and the same EICAS indications. If you hadn't already fired them manually, you would know they vented.

Do you have the QRH of all airliners or what?

[Evan]

I think what BB is trying to say in his cryptic way is there are two ways a fire extinguishing agent bottle can be "discharged".

The first is the way you describe, and results in agent being discharged through nozzles near the engine, hopefully putting out a fire if one is present.

The second is if the agent bottle is subjected to excessive heat (and thus its internal pressure increases above a safe level), there is a thermally-actuated valve that will vent the contents of the bottle to atmosphere via a separate outlet - not the nozzles near the engine.

So if you were to perform the engine-fire routine and attempt to discharge the extinguishing agent into the engine area, if the bottle were empty because it had already vented due to excessive heat, there would be no agent delivered to the engine area. And therefore no extinguishing effect.

The bottles are housed in the fuselage, not near the engines (and opposite the #1 side) so thermal venting due to a fire would not occur until the heat from the fire reached that area. In that case you would get DISCH 1 and 2 lights and the same EICAS indications. If you hadn't already fired them manually, you would know they vented.

[elaw]

I think what BB is trying to say in his cryptic way is there are two ways a fire extinguishing agent bottle can be "discharged".

The first is the way you describe, and results in agent being discharged through nozzles near the engine, hopefully putting out a fire if one is present.

The second is if the agent bottle is subjected to excessive heat (and thus its internal pressure increases above a safe level), there is a thermally-actuated valve that will vent the contents of the bottle to atmosphere via a separate outlet - not the nozzles near the engine.

So if you were to perform the engine-fire routine and attempt to discharge the extinguishing agent into the engine area, if the bottle were empty because it had already vented due to excessive heat, there would be no agent delivered to the engine area. And therefore no extinguishing effect.

[Evan]

Obviously, you missed my point entirely. A squib sits between the halon bottle and the lines that deliver the agent to the engine compartment and to certain accessories. In essence it is an electrically actuated valve. So it was not "fixed" as so stated. So if you "blew" the squib(s) and the bottles had thermally discharged and there was no agent in them, they ain't gonna do squat!

BB, I'm not sure what your point was other than to lash out at people who don't sit in the pointy end for using pointy-end vernacular. I don't agree with that. If you haven't noticed, it is also the lingua franca of aviation forums.

You seemed to miss my point (observation/speculation) that a pilot might not be aware of an uncontained engine failure (and subsequent fire) from the cockpit and that one possible clue would would be that after firing both squibs, the ENG FIRE indication was still present.

Now, why did I say 'firing the squibs'? Well, because that is essentially what you are doing when you move the fire handle. It sends an electrical signal to an electrically operated explosive device known as a squib. The signal causes the squib to 'fire' a slug into a frangible disk, thus destroying the disk and releasing the agent. A squib is not simply an electrical solenoid. It is an electrically operated explosive device (in this case).

However, if you insist on perfect technical description...

I'm sure they were looking at a fire indication but have no way to know it was uncontained (other than pulling the associated fire handle, rotating it for 1 second and then, after half a minute, rotating in the other direction for 1 sec not extinguishing the ENG FIRE indication).

Fix-ed.

That might cause a pilot to send someone back for a look out the window, no?

[3WE]

Obviously, you missed my point entirely. A squib sits between the halon bottle and the lines that deliver the agent to the engine compartment and to certain accessories. In essence it is an electrically actuated valve. So it was not "fixed" as so stated. So if you "blew" the squib(s) and the bottles had thermally discharged and there was no agent in them, they ain't gonna do squat!

So squib is the term you use to look cool on the aviation forum while solenoid is generic, but makes you look like a layman?

[BoeingBobby]

https://www.youtube.com/watch?v=R9ETlTZoF1E



Blew a squib or blew a seal?

[BoeingBobby]

Fixed (For those who need the specific verb to make out my meaning despite the obvious causal relationship between 'squib' and 'release the agent' that extinguishes).

Obviously, you missed my point entirely. A squib sits between the halon bottle and the lines that deliver the agent to the engine compartment and to certain accessories. In essence it is an electrically actuated valve. So it was not "fixed" as so stated. So if you "blew" the squib(s) and the bottles had thermally discharged and there was no agent in them, they ain't gonna do squat!