Why not using the build-in logic ??
Just set the firestatus Offset to 51 or 52 or 53.
All needed indications comes ON and ONLY by pulling the Firehandle the ENG/APU cuts, not before. This part is as well included by setting the variable/Offset, e.g. ENG1 eng1firehandlepull (should be connected to your hardware.
if firestatus = 51
FireHandleEng1 = 1
overheateng1 = 1
firesolenoideng1 = 1
firebell = 1
sixpackovhedet = 1
endif
if firestatus = 52
FireHandleEng2 = 1
overheateng2 = 1
firesolenoideng2 = 1
firebell = 1
sixpackovhedet = 1
endif
if firestatus = 53
FireHandleApu = 1
firesolenoidapu = 1
firebell = 1
sixpackovhedet = 1
endif