RE:APU on during test flight?mnztr wrote:
I noticed the APU was on while the plane taxied before takeoff, is this just to give additional redundancy in the electrical system during first flight? You can clearly see the heat plume in the freezing air as the plane moves.
They likely were planing some power transfer test during the flight or they may have done a bleeds off take-off where they would use the APU to pressurize the plane and supply cabin airconditioning.