hits into the prop-arc

[Horst Weber]

Good evening experts

Today, I've seen some German gun-camera footage, FW 190 and
Bf 110 v/s B-17 and B-24.
It is noted, that always a considerable amount of rounds from the fighters hit and blasted on the blades of the pro-arc. In particular by attacks from the rear.
My question is, how many hits, in particular by explosive ammo (20mm and 30mm) could tolerate such a prop until it didn't work proper anymore ?.

Thank you very much

Horst Weber

[ssg keay]

Horst, good question. I imagine a 30mm will rip the blade clean off. A 20mm should do close to the same damage. It depends though if the round explodes on impact or just goes right through. I found a P-47 blade with a 13mm hole in it once, but the dozen or so 20mm in the turbo were the cause of crash, not the hole in the prop. Danny

[Ruy Horta]

If we discount type of damage that simply removes (part of the) blade, it is probably difficult to quantify. I have no hard data, but I can image that even damage from a(n un)lucky single rifle caliber round might generate enough vibration to cause critical damage to the engine.