320 Questions

[SADDLER]

Can anyone answer these two questions
1. Can the APU generator replace both generators in the air and if so , what height?
2 A red light located in the locking handle`s housing area of the forward and aft cargo doors indicates what?
Thanks a lot.

[Thunderbug]

1)

A 3rd Generator (APU GEN), driven directly by the APU and producing the same output as each main engine generator, can replace either or both main engine generators at any time.

The APU can be started and used for electrics up to max operating Alt, (Air supply 1 pack below 22,000, & 2 packs below 20,000). If you are down to batteries the APU start limit is 25,000'

2) Don't know - but the main doors have red indicators in the windows to indicate that the aircraft is still pressurised.

T'bug

[SADDLER]

Thanks a lot Thunderbug.

[VillWill]

I think the "red lights" your talking about on the fwd and aft cargo doors are not lights at all, just about 6 or 7 little sightglasses that show a green or red tab when you look through them. They are an indication for each of the hinge locks on the doors and if one has not locked properly it will show a red tab through the sightglass. Im nearly sure this is what you are talking about.

[Nelli]

I'd agree with Villwill, because I can't remember any lights on the cargo doors. Only one I can remember is at the operating panel, and that's green, to indicate the door is fully open.

[Cold Soak]

Thunderbug is right, you can use the APU for electrical requirements upto any altitude. However you will only get 100% output upto 30,000 ft, then it's output ability decreases progressivley upto ceiling to around 80% give or take, isa conditions (i can't remember the exact figure!). Regarding the packs, its 2 packs upto 15,000ft and one pack to 20,000ft. Hope this helps