What was found
MMX - AIRCRAFT WOULD NOT PRESSURIZE AFTER TAKEOFF. RETURNED TO MMX. FOUND 'VENT DOOR' IN MAIN CABIN TO BE IN THE OPEN PSOITION. CLOSED THE 'VENT DOOR'. (M)
As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
MMX - AIRCRAFT WOULD NOT PRESSURIZE AFTER TAKEOFF. RETURNED TO MMX. FOUND 'VENT DOOR' IN MAIN CABIN TO BE IN THE OPEN PSOITION. CLOSED THE 'VENT DOOR'. (M)