Pneumatic air
I have a few questions on air source for the 737 800 series
1. If you have no air source (no APU, no ground air source) if you turn the RECIRC fans on, do you expect to hear noise of the fans working?
2. If you have APU off due to airport restrictions and have a ground air source connected to the mix manifold, do you still expect to see any PSI in the duct pressure? Will the Air Cond packs have any effect? Ie if i switch the packs on or off will you see the duct pressure needle fall or rise?