As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UPPER DECK ESCAPE HATCH MADE A LOUD BANG AT 23,000 FT. UNABLE TO HEAR DUE TO ESCAPING AIR. AIRCRAFT RETURNED TO AIRFIELD. LANDING NORMAL. ADJUSTED BAYONET FITTING ON THE HATCH. INSPECTED HATCH INTERIOR AND EXTERIOR IAW 52-21-00. ALL CHECKS SATISFACTORY. AIRCRAFT RETURNED TO SERVICE.