747 Engine(s) FIRE Questions?

Question

If you suffer an engine fire, you close the thrust lever, cut off the fuel control to the affected engine, pull the fire handler outwards and if the fire warning is still displayed on EICAS, rotate the fire handler.

If the fire warning goes off EICAS, does that mean the fire has been put out and if yes, is it safe to restart the affected engine?

Also, if you have a fire in your cargo forward or aft hold, and you press the discharge switch for the cargo hold, will the fire be put out or does it require human intervention (i.e: somebody using a fire extinguisher)?

Thanks :D

Answer 1

You can cut the fuel and close the lever, but pulling the fire handle will cut the fuel off. I doubt the engine would be restarted, unless it was a must have situation.



Some of the other folks on here will will chime in I am most positive, especially about the second part.

Answer 2

Remember the action of pulling the fire lever cuts of fuel, electrical, pneumatics to that particular engine and arms your fire extinguishing system, rotating the fire handle fire handle fires the bottle.

If the EICAS says the fire is out it is out. No engine where a fire bottle has been discharged is restarted.

Fires in cargo whether fwd or aft again the action of pushing the discharge switch closes inlet & outlet isolation valves of the cargo to snuff off the air (no oxygen -no fire) if it haven't close yet as the smoke alarm or sense is enough to automatically closes the said valves.

Perhaps when its a freighter & the fire is in the cabin cargo I think my friend was the flight mech and he did use the firex on a suspected cargo fire.

Answer 3

The fire is out or the system has burned through. Next step is to test the fire warning system. Good test=good news. Pilsner is right, you have shut the fuel off with pulling the handle, generally at another location (i.e. the Boeing product I fly, the fuel shut off valve closes at the EEC, the fire handle closes it at the pylon).



Next, you have three others (engines), why would you re-start? Ever heard of a FEVER check? That would be performed before restart anyway.



And, the cargo fire suppression works with HALON. Couple of different systems with the same philosophy; generally a quick discharge "knock down" bottle with discharge and then there can be a second bottle that is much slower to keep the fire down.



As somebody said here, you land as soon as possible and the airplane is down until HALON, bottles, squibs, and damage is fixed.



As somebody incorrectly said here -- NOBODY goes down in the hold with a "special" fire extinguisher. Most transport catergory aircraft, you can't even get there from here.

Answer 4

If EICAS indicates fire is out,then that's how you leave it.You do not try

for restart,you divert to nearest airport that can handel you.

Cargo hold is much the same.There are 3 very large extinguisher,bottles in the front & 3 in the rear hold.If fire in the cargo hold the aircraft should already be heading for the nearest airport,while the

extinguishing is being done..Once these bottles are activated,the aircraft stays on the ground until they are replaced & new squib activators as well..

Hope this helps..

Answer 5

To restart the engine is unsafe because the fire extinguishers already consumed.

There are some reason why engine fire happen.

The common cause of engine fire is due to fuel leaks, pneumatic leak that burn the wirings and the fuel lines, etc, no access door to get in to cargo compartment when you are inside the cabin... Just press the discharge switch to stop the fire.

Answer 6

I don't know the answer to the first question but if the discharge switch is engaged, fire can spread to other parts of the plane, usually navigators and co pilots will usually go down there and put the flames out with a special fire extinguisher