What was found
PILOT HEARD LOUD POP WHEN LOWERING THE LANDING GEAR. HAD 3 GREEN LIGHTS, VERIFIED GEAR DOWN AND LOCKED. UPON LANDING, RT GEAR DOOR WAS NOT CLOSED. INSPECTION REVEALED BROKEN GEAR DOOR BELLCRANK. PART HAD INDICATIONS OF A CRACK THAT WAS OLD. SUBMITTER RECOMMENDS MORE FREQUENT INSPECTION OF THIS AREA.