As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON FEBRUARY 8, 2009 LEAVING TORONTO THE AIRCRAFT FAILED TO PRESSURIZE AFTER TAKEOFF THEN RETURNED TO GATE. MAINTENANCE ACTION CONFIRMED THE L1 ENTRY DOOR GUIDE ARM JAM NUT WAS LOOSE CAUSING THE DOOR TO MIGRATE OUT OF RIG. THE GUIDE ARM WAS RE-ADJUSTED. WEST JET CONSIDERS THIS SDR CLOSED.