What was found
TRANSMISSION COVER (AS REFERENCED IN PIPER PA-24-180 SM SECTION 6, FIG 6-13, ITEM 7), FAILED BY CRACKING AROUND ATTACHMENT LUG. LUG BECAME LIBERATED FROM REMAINING PORTION OF COVER. FAILURE CAUSED LANDING GEAR TO NOT LOCK IN DOWN POSITION. SUBMITTER RECOMMENDS PAYING PARTICULAR ATTENTION TO THIS AREA DURING INSPECTION OR REPAIR. FAILURE COULD BE INDUCED BY HARD LANDING OR IMPROPER GEAR RIGGING.