What was found
HIGH PITCHED WHISTLE COMING FROM THE MAIN CABIN DOOR CLIMBING FROM 7,000 - 9000 FT AND DESCENDING FROM 6100 - 5300 FT. TROUBLESHOT DISCREPANCY FOUND THE DOOR SEAL DETERIORATED . GAIN ACCESS TO THE MAIN ENTRY DOOR SEAL . REMOVED AND REPLACED WITH A NEW SEAL CABIN DOOR WITH A NEW HARWARE . ACCOMPLISHED THE CABIN DOOR POST MAINTENANCE CHECKS . COMPLIED WITH CABIN DOOR OPERATIONAL CHECKS TEST PASS OK . IAW MM 52-10-00 AND 21-30-00