How big does hail have to be to damage a parked aluminum aircraft? Is there anything to do about it if you haven't got a hangar for the plane? I've been hiking in hail near Bryce canyon one time when we needed to put on our climbing helmets and shelter under trees. Had some little pea-size hail come through my area yesterday. Got me wondering when to worry.
-DP

Problem with hail is that its hard to predict and often occurs several dozens of miles from the frontal systems producing it.
Density (and hence weight) are very different as well, so you can have fairly small hail corns carrying a lot of energy upon impact.

We had golf ball size hail a few weeks back, leaving a path of destruction in some areas, where others barely reported a sprinkle of rain. I'd say anything larger than nickel size in diameter bears risk for surface and paint damage, glass and plexiglass being at highest risk.

Any sort of cushioning will alleviate many of the problems, such as padded wing covers or outside windshield covers (unless blown away). The state of paint (soft or hardened by years of exposure) and age of paint also play a role in how well the surface deals with the smaller impacts.

I thought this was interesting since we were on the subject of hail.
http://dptv.denverpost.com/2015/06/05/r ... in-denver/

Lots of hail in the Denver area recently.

We had 2-3" hail at our home last Wednesday and the roof took a beating. Time to test out the home owners insurance policy...

I've always thought that an airplane cover than integrated a suspended layer about 4" above the top surfaced of the aircraft and wings could protect against hail-- trampoline that shit right off.