Narrative:

ZZZZ to ZZZ VFR; landed; then while taxing to end of runway to go to customs; front of plane lowered about 8' inches; I assumed flat tire. Instead of stopping on runway; I exited onto gravel north of runway and stopped plane; called tower and stated clear of runway and that we would need a tow. Upon exiting plane with my family; I inspected the plane and found no damage to airframe; propellers; or [landing] gear doors. It appeared the nose gear was aft of its normal position. Fire department; sheriff's department and customs arrived and fixed base operator (FBO) with there toter [tow vehicle]. They were trying to load the plane on toter when the airport manager (apm) loaded us in his car and drove us to FBO. This being hurricane season; I cannot leave this plane sitting in ZZZ. I called my mechanic; he said to tear it [landing gear] apart and get some part numbers (P/ns) and he will be down and repair. I went down the next day to ZZZ and found they damaged plane while towing it to parking area. When front nose gear removed; found right-hand upper trunnion bolt to be broken off. Upon examination by mechanic; part had been drilled wrong and cracked and split over time. I think removal of all trunnion parts during annual [inspection] would prevent this. You would not find this by just swinging the [nose] gear. Airplane was examined and repaired by mechanic and returned to service (rts) approximately seven days later.

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Original NASA ASRS Text

Title: Pilot reports his Mitsubishi MU2 aircraft Nose Landing Gear collapsed eight inches after landing. A reused right-hand Nose Gear Trunnion pin had failed due to improper maintenance.

Narrative: ZZZZ to ZZZ VFR; landed; then while taxing to end of Runway to go to Customs; front of plane lowered about 8' inches; I assumed flat tire. Instead of stopping on runway; I exited onto gravel North of runway and stopped plane; called Tower and stated clear of runway and that we would need a tow. Upon exiting plane with my family; I inspected the plane and found no damage to airframe; propellers; or [Landing] Gear doors. It appeared the Nose Gear was aft of its normal position. Fire Department; Sheriff's Department and Customs arrived and Fixed Base Operator (FBO) with there Toter [Tow Vehicle]. They were trying to load the plane on Toter when the Airport Manager (APM) loaded us in his car and drove us to FBO. This being hurricane season; I cannot leave this plane sitting in ZZZ. I called my Mechanic; he said to tear it [Landing Gear] apart and get some Part Numbers (P/Ns) and he will be down and repair. I went down the next day to ZZZ and found they damaged plane while towing it to parking area. When front Nose Gear removed; found right-hand Upper Trunnion bolt to be broken off. Upon examination by Mechanic; part had been drilled wrong and cracked and split over time. I think removal of all Trunnion parts during Annual [Inspection] would prevent this. You would not find this by just swinging the [Nose] Gear. Airplane was examined and repaired by Mechanic and Returned to Service (RTS) approximately seven days later.

Data retrieved from NASA's ASRS site as of July 2013 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.