What was found
INVESTIGATED PILOT COMPLAINT OF LOOSE FUSELAGE SKIN RIVETS AT CABIN DOOR HINGE AREA. FOUND FUSELAGE DOOR FRAME CHANNEL CRACKED. CABIN DOOR DAMPER ACTION ALSO REPORTED AND FOUND TO BE WEAK. SUSPECT CAUSED BY CABIN DOOR "BOTTOMING OUT" EXCESSIVELY HARD OR EXCESSIVE WEIGHT ON DOOR OVER REPEATED CYCLES. TECH/ INSPECTORS SHOULD CHECK DOOR DAMPNER OPERATION AT SCHEDULED PHASE INSPECTIONS AND CORRECT IF WEAK OPERATION NOTED. EVIDENCE OF LOOSE HINGE AREA RIVETS SHOULD ALSO BE INVESTIGATED FOR POSSIBLE CRACKED STRUCTURE UNDER THRESHOLD. (K)