I think for a 3D flight sim you shouldn't use rotateentity at all, instead use Turnentity and feed it directly with the forces of the flight controls: the average of both tail planes that are both above or both below the normal level will give you the pitch to TURN. The diffrence of both of them will also give you the roll to turn (well, if it's a jet fighter thing)
And for the camera, I'd suggest to calculate a point that is behind the camera and then rubber-band-move the camera to that point continously (smoothed). Or you coul d even parent the camera to the plane. Or you can parent a dummy pivot to the airplane and then rubber-nand-move the camera to that pivots position, and simply point the camera to the airplane.
And for the camera, I'd suggest to calculate a point that is behind the camera and then rubber-band-move the camera to that point continously (smoothed). Or you coul d even parent the camera to the plane. Or you can parent a dummy pivot to the airplane and then rubber-nand-move the camera to that pivots position, and simply point the camera to the airplane.