Originally Posted by
pattern_is_full
I
And there is a good explanation for that - whatever the aerodynamic forces acting on the blade after separation, they likely have on the close order of 0.01 seconds to produce any relative motion fore or aft. Once released, the blade will be moving laterally at about 94m/s (339kph), and only has to travel about 1m to reach the fuselage (assuming it will hit it at all) on most transport turboprops.
(Math is: 2-meter blade, 1-meter half radius. At 1800 rpm the half-radius is travelling at pi x R x 1800 = 5654m/minute or 94m/sec average speed. The motion of a thrown blade is a pirouette around the blade's center of mass, tip over root, like a thrown boomerang).
It is relevant for this particular event that the propellers on a Saab 2000 stay below 1100 rpm at normal operation, though possibly marginally above that while reversing. The numbers become correspondingly lower. Although separating at collision with a rock wall makes its trajectory after separation very unpredictable, to say the least. Compare with a bullet shot out of a rifle versus a musket gun.