What was found
PASSENGER DOOR UPPER STAIR PANEL ASSY UPPER AND LOWER PANEL HINGES (WHERE ATTACHES TO STAIRS) ARE CRACKED. CORRECTIVE ACTION: REMOVED AND REPLACED PASSENGER DOOR UPPER STAIR PANEL UPPER AND LOWER HINGES(PN: 601R31980-63/606-31980-10) CRJ 900 ARM 51-21-01, 51-42-06, 51-41-02, 51-25-06, 51-40-11, 51-21-16