Narrative:

Event: a landing gear downlock pin was left in the center landing gear of an airplane on a scheduled flight dfw to ord. Chain of events: problem discovered after takeoff from dfw when landing gear were retracted. The center gear failed to come up. Landing gear cycled up, then down, but this failed to correct problem. Dfw tower relayed through departure control that center gear was in down position. Corrective actions: aircraft diverted to tul to have gear checked. Landing at tul uneventful. Maintenance discovered downlock pin in center gear. Pin removed. Aircraft dispatched to ord. How problem arose: aircraft had been at dfw maintenance hangar for previous 2 days. Gear pin thought to be installed at hangar. Maintenance failed to remove pin after towing aircraft from hangar to departure gate. Mechanic assigned to help ensure on-time departure failed to discover gear pin on his preflight inspection. F/east did not discover gear pin on his preflight inspection. Push crew at gate did not discover gear pin. It is the opinion of the writer that the gear pin did not have a flag attached that would have made the pin easy to see. With a flag attached it is hard to believe that the gear pin would not have been seen by someone who was preflting the aircraft and as such was checking to make sure all gear pins were removed before flight. How to prevent in future: 1) all gear pins must have flags attached to them to make them obvious. 2) stress to all concerned (maintenance, tow crews, pushback crews, flight crews, etc) the absolute importance of ensuring the downlock pins are left in place. Supplemental information from acn 117626: event: F/east did not personally conduct exterior preflight inspection. Chain of events: diverted to tul (dtw-ord) because gear downlock pin not removed from center landing gear. Maintenance personnel conducted exterior walk-around after removing gear pin. (Note: separate NASA report submitted on gear pin). How problem arose: problem arose from a change from the routine--ie, divert, extra company communications, having to change destination after takeoff, etc. Human factors: 1) crew upset at having to divert. 2) crew members worried about who is to blame for gear pin left in place. 3) what will be punitive actions of company and FAA for having to divert? 4) change in routine. 5) being in the 'spotlight'--there were a lot of men in 'coats and ties' observing from ramp level at the gate in tul. How to prevent in future: 1) follow established procedures. 2) do not rush or get in a hurry. 3) from FAA and company standpoint, do not make crews feel as though their every little mistake will cost them their jobs; this increases pressure upon the crew member(south) involved and compounds problems.

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Original NASA ASRS Text

Title: ACR ACFT DIVERTS TO ANOTHER ARPT WHERE MAINTENANCE CAN CHECK GEAR WHICH WOULD NOT RETRACT ON TKOF.

Narrative: EVENT: A LNDG GEAR DOWNLOCK PIN WAS LEFT IN THE CENTER LNDG GEAR OF AN AIRPLANE ON A SCHEDULED FLT DFW TO ORD. CHAIN OF EVENTS: PROB DISCOVERED AFTER TKOF FROM DFW WHEN LNDG GEAR WERE RETRACTED. THE CENTER GEAR FAILED TO COME UP. LNDG GEAR CYCLED UP, THEN DOWN, BUT THIS FAILED TO CORRECT PROB. DFW TWR RELAYED THROUGH DEP CTL THAT CENTER GEAR WAS IN DOWN POS. CORRECTIVE ACTIONS: ACFT DIVERTED TO TUL TO HAVE GEAR CHKED. LNDG AT TUL UNEVENTFUL. MAINT DISCOVERED DOWNLOCK PIN IN CENTER GEAR. PIN REMOVED. ACFT DISPATCHED TO ORD. HOW PROB AROSE: ACFT HAD BEEN AT DFW MAINT HANGAR FOR PREVIOUS 2 DAYS. GEAR PIN THOUGHT TO BE INSTALLED AT HANGAR. MAINT FAILED TO REMOVE PIN AFTER TOWING ACFT FROM HANGAR TO DEP GATE. MECH ASSIGNED TO HELP ENSURE ON-TIME DEP FAILED TO DISCOVER GEAR PIN ON HIS PREFLT INSPECTION. F/E DID NOT DISCOVER GEAR PIN ON HIS PREFLT INSPECTION. PUSH CREW AT GATE DID NOT DISCOVER GEAR PIN. IT IS THE OPINION OF THE WRITER THAT THE GEAR PIN DID NOT HAVE A FLAG ATTACHED THAT WOULD HAVE MADE THE PIN EASY TO SEE. WITH A FLAG ATTACHED IT IS HARD TO BELIEVE THAT THE GEAR PIN WOULD NOT HAVE BEEN SEEN BY SOMEONE WHO WAS PREFLTING THE ACFT AND AS SUCH WAS CHKING TO MAKE SURE ALL GEAR PINS WERE REMOVED BEFORE FLT. HOW TO PREVENT IN FUTURE: 1) ALL GEAR PINS MUST HAVE FLAGS ATTACHED TO THEM TO MAKE THEM OBVIOUS. 2) STRESS TO ALL CONCERNED (MAINT, TOW CREWS, PUSHBACK CREWS, FLT CREWS, ETC) THE ABSOLUTE IMPORTANCE OF ENSURING THE DOWNLOCK PINS ARE LEFT IN PLACE. SUPPLEMENTAL INFO FROM ACN 117626: EVENT: F/E DID NOT PERSONALLY CONDUCT EXTERIOR PREFLT INSPECTION. CHAIN OF EVENTS: DIVERTED TO TUL (DTW-ORD) BECAUSE GEAR DOWNLOCK PIN NOT REMOVED FROM CENTER LNDG GEAR. MAINT PERSONNEL CONDUCTED EXTERIOR WALK-AROUND AFTER REMOVING GEAR PIN. (NOTE: SEPARATE NASA RPT SUBMITTED ON GEAR PIN). HOW PROB AROSE: PROB AROSE FROM A CHANGE FROM THE ROUTINE--IE, DIVERT, EXTRA COMPANY COMS, HAVING TO CHANGE DEST AFTER TKOF, ETC. HUMAN FACTORS: 1) CREW UPSET AT HAVING TO DIVERT. 2) CREW MEMBERS WORRIED ABOUT WHO IS TO BLAME FOR GEAR PIN LEFT IN PLACE. 3) WHAT WILL BE PUNITIVE ACTIONS OF COMPANY AND FAA FOR HAVING TO DIVERT? 4) CHANGE IN ROUTINE. 5) BEING IN THE 'SPOTLIGHT'--THERE WERE A LOT OF MEN IN 'COATS AND TIES' OBSERVING FROM RAMP LEVEL AT THE GATE IN TUL. HOW TO PREVENT IN FUTURE: 1) FOLLOW ESTABLISHED PROCS. 2) DO NOT RUSH OR GET IN A HURRY. 3) FROM FAA AND COMPANY STANDPOINT, DO NOT MAKE CREWS FEEL AS THOUGH THEIR EVERY LITTLE MISTAKE WILL COST THEM THEIR JOBS; THIS INCREASES PRESSURE UPON THE CREW MEMBER(S) INVOLVED AND COMPOUNDS PROBS.

Data retrieved from NASA's ASRS site as of August 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.