Device: iPad Air 3
Operating system: IOS 15.6.1
I have realized recently that in some aircraft, when you turn the APU on, right when the APU switches from start to on, the sound vanishes. I’ve noticed it on the F/A-18E, 757-200, 737 family, A350-900, A330-900, A330-300, A320 family, and the A220. Sorry for the inconvenience.