As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF THE L1 DOOR WAS NOT PROPERLY CLOSED AND DID NOT PRESSURIZE. AIR RETURN AND HAD OVERWEIGHT LANDING. OPENED AND RECLOSED L1 DOOR, CHECKS GOOD PER AMM 52-11-00. NO DEFECTS NOTED. O/W LANDING INSP C/W PER AMM 05-51-35 PHASE 1. NO DEFECTS NOTED.