Originally Posted by
FAULTPUSH
At Frontier it's APU bleed on, crossbleed to Auto. Running both packs on one engine with the APU at idle burns more gas than running both packs on the APU. If you want real fuel savings, do APU off, and crossbleed AUTO until you do the crossbleed engine start. One pack will keep up with the AC requirements just fine under any circumstances I've seen.
Spirit's is X-BLEED AUTO, APU BLEED OFF, Y HYD PUMP on until we start #2. That is...until 12:01am Saturday. After that, we don't start any engines until we get a contract. That should save a lot of fuel!