As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR TURNBACK AFTER TAKEOFF LOUD NOISE FROM OVERHEAD HATCH. CARRIED OUT HATCH SEAL CHECK AND DOOR CUTOUT CHECK FOR ABNORMALITIES ALL OKAY. FOUND HINGE BOLTS LOOSE. TIGHTENED SAME PER STANDARD PRACTICES. PRESSURIZED AIRCRAFT AND LEAK CHECKED, NO LEAKS NOTED.