Not seen any failures but we were getting through quite a few C130J props out in Afghanistan. Our limits on damage are, in my opinion, overly cautious - small dents being enough to render the prop unserviceable. Ours is a composite blade with steel leading edge stone guard. I suspect there are fears about delamination of the prop or the shedding of a damaged stone guard in flight. The older C130 with the all metal prop has far fewer problems with dents and knicks just being filed down
