As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR RETURN FOR LOUD SQUEAL IN COCKPIT, COULD NOT HEAR. PRESSURIZED FIRST OFFICERS SLIDING WINDOW. FOUND LEAK AT FWD UPPER CORNER. ADJUSTED WINDOW CLEARANCE IAW MM 56-12-11-820-801. INSPECTED SEAL & PRESSURIZED TO 5.5 PSI. NO LEAKS OR PRESSURIZATION FAULTS FOUND, OK TO CONTINUE.