What was found
LOUD NOISE HAPPENED WHILE CLIMBING THROUGH FL200. NO PRESSURIZATION ISSUES IDENTIFIED. NO CAUTION NO WARNING NO STATUS MESSAGES ON EICAS ALERTING US OF AN ISSUE. CREW REPORTED THE LANDING WEIGHT WAS 65K AND VSI WAS LESS THAN 360FPM. PERFORMED INSPECTION REFERENCE AMM TASK FOUND A PORTION OF THE MCD SEAL OUT OF THE TRACK, CLEANED SEAL AND RE-INSTALLED INTO RETAINER. PRESSURIZED AC REFERENCE AMM TASK, NO DEFECTS NOTED. OK FOR CONTINUED SERVICE.