Hello all,
Please forgive my (possible) misinterpretation or lack of understanding, first off.
Regarding the A320 OE Taxi, there is a comment in FCOM Supplementary procedures that goes like this;
Apply normal "AFTER START" procedures, but:
- Keep APU running to supply engine fire extinguishing, avoid electrical transients and allow the galley operation.
I can quite understand the second and third "reasons", but I do not get the engine fire extinguishing bit at all. There is no further qualification that I can see in the FCTM, either, on this subject. Looking at the FCOM electrical supply for Fire Protection, I get;
Engine fire loops on DC2 & DC ESS. Engine squibs on HOT 1, HOT 2 & DC2. Far as I know, these buses are available with Engine 1 started and the APU or APU GEN - OFF, and therefore fire extinguishing is supplied to both engines, anyway, regardless of APU.
Can anyone please state exactly
what the APU is
supplying to the engine fire extinguishing?
Thanks in advance, and sorry if this has been covered before, but I found no current threads which included it.