What was found
AFTER DEPARTURE, FOR REPOSITIONING FLIGHT, CREW NOTED EXCESSIVE CABIN ENTRY DOOR SEAL LEAKAGE AT 16,000 MSL, CABIN ALTITUDE CHANGE RATE EXCESSIVE. RETURENED TO DEPARTURE. FOUND HOLE IN CABIN DOOR SEAL. AFTER REMOVAL OF SEAL FOR REPAIRS, FOUND PN 80-111388-025 SEAL RETAINER CHANNEL CRACKED AT RADIUS. REPLACED DOOR SEAL RETAINER WITH OPERATOR-SUPPLIED SERVICEABLE RETAINER AND REPAIRED DOOR SEAL. FAILURE CAUSE UNKNOWN, MAY BE RELATED TO DOOR RIGGING OR CYCLE FATIGUE.