I've seen that type of damage on other motors before. A piece broke off one of the compressor blades and rattled around in there, damaging the other compressor blades.

On my motor (that did it twice) the piece was finally ejected out *through* the FOD screen. Initially, I thought it was a failure of the FOD screen and something had punched through and gotten in there. However, upon further close examination of the FOD screen, it was seen that the broken strands around the hole were bend *out* not *in*, indicating that the foreign object came from the compressor wheel itself and was launched *out* through the FOD screen.

This failure has become somewhat less prevalent now that must compressor wheels are machined from billet vs. being cast, but it still happens.

Bob

edit: the motors that I have seen this in were not Kingtechs....