As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LOUD SQUEAL HEARD DURING DECENT FROM 7500 FT ALL THE WAY DOWN TO 5000 FT. 2.7 PRESSURE DIFFERENCE WHEN SQUEALING STOPPED. NO SQUEAL DURING CLIMB OR CRUISE. CABIN DOOR SEAL DETAILED INSPECTION CARRIED OUT WITHOUT FINDINGS IAW MM 52-10-00-222 REV.20. APU PRESSURIASTION RUN CARRIED OUT AS PER TEXTRON`S EMAIL. NO FAULTS FOUND. CREW TO REPORT FURTHER.