This whole shebang is interesting to me , but in the wrong way.
LET US SAY an engine started spewing flames from the rear of the engine.
IT IS AT NIGHT, very scary to the passengers who can see it.
BUT THE PILOTS may only have an indirect understanding of what is happening like engine vibration (due to bird strike on fan), higher EGT
or even the tower calling them on the radio or a flight attendant yelling over the intercom/interphone.
So, you shut off the fuel to the engine (and do the checklists). You call for CFR over the radio.
BUT YOU REALLY SHOULD NOT EVACUATE into the engine!
YOU MIGHT consider you have torching and not a true fire as the nacelle detectors do not show a fire if it is coming out the rear of the engine (where hot gas is a normal thing)
AS you all know, shooting a fire bottle in the engine nacelle will not put out torching and the need to (depending on the time/situation) motor, or cut fuel or other things should come first.
SO, maybe they should NOT have evacuated. AND certainly not on the "FIRE" side.
MANY questions here. HOPE we hear the truth someday.
I still remember watching the following happen at KDCA.
Competitor's MD80 pushes back and starts engines. TOWER SAYS FLAMES COMEING OUT rear of engine.
PLANE acknowledges
MECHANIC is on FREQ YELLING at pilots to NOT SHOOT THE BOTTLES.
THEY SHOOT BOTH BOTTLES and I can see the nacelle expand with each shot.
BUT they do nothing as the problem is torching (or jet pipe fire if you are british) and they finally (as the fuel is shut off) go out.
Be careful boys!