What was found
PILOT REPORTED DOOR CAME OPEN IN FLIGHT. UPON LANDING, IT WAS FOUND THE MAIN CABIN DOOR HAD DEPARTED AIRCRAFT. DOOR WAS RECOVERED. DURING INSPECTION AND DISASSEMBLY OF THE DOOR, SEVERAL ISSUES WERE FOUND. 1) UPPER FORWARD LATCH HOOK WAS FOUND WITHOUT RIGGING HOLES INSTALLED AND WAS INCORRECTLY RIGGED. 2) DOOR BELLCRANK, PN 50-430031-29 WAS FOUND BENT AND TWISTED. 3) MAIN CABIN DOOR LATCH BRAZE ASSEMBLY WAS CATCHING ON HOOK. DID NOT ALLOW FOR A SMOOTH TRANSITION TO A LOCKED POSITION. (K)