# NTSB SEA99LA073: Cessna 180K, N2567K, Bremerton, WA, May 23, 1999 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 23, 1999, 15:35 local (22:35 UTC) - Place: Bremerton, WA - Coordinates: 47.570384, -122.630149 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=47.5704&lon=-122.6301&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report January 18, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 46604 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA99LA073 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/46604/pdf - Page: https://openairdocs.org/ntsb/SEA99LA073 ## Probable cause Failure of the landing gear attach bolt due to fatigue failure resulting in the left main landing gear collapsing. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, landing - roll - landing gear,main gear attachment - fatigue (cause) ## Analysis The pilot reported that he performed a normal wheel landing. During the landing roll, the left main gear leg failed. Post-accident inspection revealed that the attachment bolt from the gear leg broke in two pieces. During the metallurgical examination, the specialist found that three major fracture zones were present. Two of the zones were fairly flat and propagated on a plane that was perpendicular to the bolt axis, typical of fatigue progression. One of the zones was covered with heavy accumulation of oxides and corrosion deposits. The other zone was free of oxidation and deposits. The third zone displayed a fracture propagation on a 45 degree slant. This zone was typical of a final overstress separation. The fatigue zones occupied about 75 percent of the bolt cross section at the fracture location. The specialist reported that the presence of oxide and corrosion deposits suggested an 'old crack.' There was no evidence found of thread stripping. Maintenance records indicate that since the time of manufacture in 1978, the aircraft had accumulated a total time of 77 hours. During this time, there were several years in which the aircraft had not been operated. ## Factual narrative On May 23, 1999, approximately 1535 Pacific daylight time, a Cessna 180K, N2567K, impacted the runway at Bremerton National Airport, Bremerton, Washington, after the failure of a main gear leg during the landing roll. The private pilot, who was the operator of the aircraft, was not injured, but the aircraft sustained substantial damage. The 14 CFR Part 91 flight, which departed Crest Airpark, Covington, Washington, about 30 minutes earlier, was being operated in visual meteorological conditions. No flight plan had been filed, and there was no report of an ELT activation. According to the pilot, who was performing a wheel landing, the touchdown was normal. But as the landing roll continued, he lost control of the aircraft when the left main gear leg failed. Immediately after the gear failed, the aircraft settled onto the runway and slid to a stop. Post-accident inspection revealed that the attachment bolt from the gear leg broke in two pieces. The bolt was sent to the National Transportation Safety Board Materials Laboratory, Washington D.C. for examination. The specialist reported that "the bolt separated at the edge of the self-locking nut, through the first thread on the shank." Further examination with the aid of a low-power binocular microscope revealed three major fracture zones. The specialist reported that two of the zones were "fairly flat and propagated on a plane that was roughly perpendicular to the bolt axis, typical of fatigue progression." One of the zones was covered with heavy accumulation of oxides and corrosion deposits. The other zone was free of oxidation and deposits. The third zone displayed a fracture propagation on a slant (45 degree) plane. The specialist reported this zone as "typical of a final overstress separation." The specialist reported that "the fatigue occupied approximately 75 percent of the bolt cross section at the fracture location." The specialist also reported that the presence of oxide and corrosion deposits suggest an "old crack." There was no evidence found of thread stripping. The aircraft was purchased new in 1978. The aircraft maintenance logbooks indicate that that the aircraft had accumulated about 38 hours of total time at the annual inspection performed in March of 1981. The next annual inspection was signed off in June 1995, with a total time still indicating 38 hours. In February 1999, the logbook indicated an annual inspection with a total time of 69.5 hours accumulated. The pilot reported a total aircraft time of 77 hours at the time of the accident. ## Aircraft - Registration: [N2567K](https://openairdocs.org/aircraft/N2567K), registered now, S/N 18052990, built 1978 (OpenAirDocs) - Reported make and model: Cessna 180K - Registry model: [Cessna 180K](https://openairdocs.org/model/cessna-180k) (registry code 2072624) (OpenAirDocs) - Registry engine: [Continental O-470 series](https://openairdocs.org/engine/continental-o-470-series) (registry code 17026, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 18052990 - Airframe hours: 77 - Engines: Continental O-470-U 230 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Kenneth D. Bryant - Registered owner: Cessna Aircraft Factory - Airworthiness certificate: Standard, Normal - Last inspection: Annual, February 2, 1999, 8 hours before - Departed: S36, CREST AIRPARK, WA - Destination: PWT - Airport: PWT, Bremerton National, runway 1, 6,200 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 42; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 345 total, 40 in this make and model, 11 in the last 90 days, 1 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 50° at 9 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 48 °F - Altimeter: 30.00 inHg - Observed at: PWT ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 19990523044299A](https://openairdocs.org/incident/19990523044299A), May 23, 1999: Cessna 180K, Bremerton, WA, No damage. (-23) A/c caught a wind gust on approach to airport. Lined back up with runway and set down on left wheel, gear collapsed. From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.