What was found
AC AFTER TAKEOFF, LOUD WHISTLING NOISE HEARD AND AC HAD PROBLEMS PRESSURIZING. AC MADE UNSCHEDULED STOP, WITH NORMAL LANDING. FOUND F.O.D. AND DEBRIS IN MAIN CARGO DOOR SILL AREA. REMOVED F.O.D. AND DEBRIS FROM CARGO DOOR SEAL AREA IAW 52-70-00. SEAL FOR MAIN CARGO DOOR INSPECTED IAW A300 52-36-11 SUPPLEMENT MANUAL, SEAL LEAK CK SATISFACTORY. AC RETURNED TO SERVICE. (A)