It's weird. Can't move my head around at all like I used to. for example, I could look and lean left and right to look down - now it's just moving to my view positions I had locked in prior to ....waaait a minute. Prior to flying wit Oculus, I had head position settings saved for particular aircraft to maximize the view for my joystick HAT. I think that if you had a previous head setting saved, it'll over-ride Rift's ability to look around - utilizing my joystick hat settings. Let me check and verify but if true, it's a bug for Aces High, not the Rift.
I'll report back here shortly.