Pen Air Saab Overrun Unilaska with Injuries

[lomapaseo]

Originally Posted by tdracer

Yes, but the momentum of a propeller blade is significant, and what if you don't have a meaningful forward speed when it lets go (e.g. takeoff power setting)? A prop can move a long way in that fraction of a second before drag takes over. If you're going to try to protect the fuselage, you need to assume it might go forward from the plane of rotation.
For uncontained engine failures I think the assumed scatter trajectory was +10/-10 degrees for high energy debris (-30 degrees for low energy debris IIRC). For a released propeller blade think you'd need assume something like +10/-30 degrees - given the distance from the engine to the fuselage that's a pretty large chunk of fuselage you'd need to protect.

Your summary is fine, Not practical to protect so lower your window shade and don't think about it

Don't confuse momentum fore and aft with polar moment of inertia because the fore and aft considerations are only in regard to the fuselage which is also moving with the prop