What was found
ON SELECTING GEAR DOWN ON APPROACH. LANDING GEAR RELAY CIRCUIT BREAKER TRIPPED IMMEDIATELY. AFTER PERFORMING "FAILURE OF LANDING GEAR TO EXTEND NORMALLY" CHECKLIST, GEAR WAS DETERMINED UNSAFE. "LANDING GEAR MANUAL EXTENSION" CHECKLIST PERFORMED, LANDING GEAR EXTENDED AND DEEMED SAFE FOR LANDING. MX PERFORMED GEAR SWINGS AND CIRCUIT BREAKER TRIPPED. R & R PCB, IAW AIM, OPS CHECKED GOOD. PERFORMED GEAR SWING IAW AIM, OPS CHECKED GOOD.