What was found
AIRCRAFT WAS FORCED TO MAKE A GEAR UP LANDING, DAMAGING PROP AND ENGINE. THE CAUSE WAS FOUND TO BE THE FAILURE OF A BEARING/WHEEL ASSEMBLY THAT ACTUATES THE NOSE GEAR DOORS CLOSING MECHANISM. THE BEARING FAILED ALLOWING THE WHEEL PORTION TO SHIFT OUTBOARD EXPOSING THE ATTACHING BOLT WHICH WAS NOW STRIKING THE SIDE OF THE NOSE GEAR FORK. THIS BOLT JAMMED THE FORK IN THE UP POSITION. IF THE ASSY WAS DESIGNED WITH A LARGE AREA WASHER INSTALLED INBOARD AND OUTBOARD OF THE BEARING THE WHEEL WOULD NOT SHIFT IF BEARING FAILED.