For purposes of 447, camber is not relevant? Surely for low speed, and a way to shade the Tail Down force w/o so much elevator? At cruise speed, its drag does not mean so much? As with the Vertical Stabilizer, why not a symmetrical airfoil, since lift is supplied by an active surface without the thickening of asymmetrical chord?
When THS stalls, aren't elevators just spoilers in costume? As in, when in 447's type of descent, a little ND elevator will slightly slow the Tail's vertical velocity by adding drag to the longitudinal? As the tail regains some airflow with a diminishing AoA, so gains the THS some lift to merely lift the nose to some stabilised (STALLED) value?
BEA states that the AoA "when valid" was never below 30 degrees NU. Were they hinting that the AoA was fluctuating in descent? Were the pilot's trying to porpoise the nose to gain what they thought was nose up to terminate the (natural, and flying) descent? If they believed they had ALTERNATE LAW, and had Pitch Protection, they were then attempting the decrease in "Speed" that would have been their responsibility w/o A/P, and A/T ?
take care mm43.
Last edited by bearfoil; 9th Jul 2011 at 00:26.