A good SOP should be simple and apply to the widest range of scenarios for a given circumstance. Thus for a fire warning during takeoff (before V1) the takeoff should be rejected. Follow the RTO SOP; stop the aircraft a.s.a.p. with all available means. The evaluation as to which engine has a fire, use of shutdown drill, and whether to evacuate should then follow logically. Follow SOPs for shutdown / evacuation after assessing the situation (quickly).
For those who had not read the MAN accident report one of the significant points was that the circumstances were a combination of rare events that although they may happen again the probability of fatalities should be very much lower, providing the salient recommendations are heeded.
The cause of the MAN accident
was an uncontained failure of the left engine, initiated by a failure of the No 9 combustor can which had been the subject of a repair. A section of the combustor can, which was ejected forcibly from the engine, struck and fractured an underwing fuel tank access panel. The fire which resulted developed catastrophically, primarily because of adverse orientation of the parked aircraft relative to the wind, even though the wind was light.
To address the technical failure it was recommended “that direct fusion weld repair of circumferential cracks in JT8D engines combustor cans should be deleted from all approved Engine Overhaul Manuals.”
A major contributor factor was the vulnerability of the wing tank access panels to impact; this was addressed by requiring that existing external fuel tank access panels are not vulnerable to impact from engine or wheel/tyre failures.
The major cause of the fatalities “was rapid incapacitation due to the inhalation of the dense toxic/irritant smoke atmosphere within the cabin, aggravated by evacuation delays caused by a forward right door malfunction and restricted access to the exits.”
Much work has been undertaken in widening escape routes; most modern aircraft meet new requirements formulated as a result of MAN.
It was recommended “
that operators should amend their Operations Manuals, if necessary, to direct crews on any rejected take-off or emergency landing to stop on the runway and review the situation before a decision on clearing the runway is made.”
and
“
Consideration should be given to the requirement to fit an evacuation alarm permitting flight deck crew to instruct cabincrew to initiate an evacuation immediately, or if the aircraft is still moving to prime for an evacuation immediately the aircraft is brought to a halt.”
Thus IMHO use reverse to stop. Assess the situation. If you decide to evacuate then act quickly.
Keep things simple, do not clutter the thought process with which engine is on fire until you have stopped, remember that you are not going to get reliable external help at all airports around the world, thus practice assessing the situation as presented (e.g. worst case dark foggy night in a simulator).
Follow SOPs, they (should) have been thought out on the ground to cover most eventualities.
Remain focused on the essential issues – ‘when the fire bell rings everything is back and white’ – you will have a nasty fright, but the resolution of the problem is down to you.