As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING INTIAL CLIMB CABIN DOOR WAS MAKING A WHISTLING SOUND THAT DEVELOPED INTO A HOWL. CABIN WOULD NOT MAINTAIN MORE THAN A 4.0 PSI DIFFERENTIAL. RETURNED TO BASE. INSPECTED SEAL AND FOUND IT MISALIGNED AT TOP MIDDLE POSITION, ADJUSTED SEAL AND APPLIED PRC TO TOP OF DOOR FRAME, IAW MM 52-10-50.