So explain how these head movements work?
If it's moving your view, then the head would move, but your view exterior to the plane would move also!
I notice the controls were moving every time as well, is head position tied to the control deflection??
That seems odd.
Also, there was an old 109 video somebody put out a while back... Notable elements included a cockpit shot with things like fuzzy dice, a cupholder, in-dash DVD player with (I think?) Deep Space 9 playing, and in another shot from the exterior, the pilot was rocking his head to the beat like yours.
I've always wondered if it was a frame-by-frame edit (i.e. faked, like the interior cockpit shot) or if it was just something I was never able to figure out in-game.