# NTSB SEA06LA166: Piper PA-24-250, N6249P, Auburn, WA, August 19, 2006 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: August 18, 2006, 19:05 local (Aug 19, 2006, 02:05 UTC) - Place: Auburn, WA - Coordinates: 47.327777, -122.226669 - Nearby events: https://openairdocs.org/map.md?lat=47.3278&lon=-122.2267&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report February 26, 2007 - Report: Approved by Office Director - Parties: Federal Aviation Administration - NTSB case key (mKey): 64428 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA06LA166 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/64428/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=64428 - Page: https://openairdocs.org/ntsb/SEA06LA166 ## Probable cause The failure of the landing gear's normal retraction/extension assembly due to an overload condition. ## Analysis After taking off and determining that the landing gear would not retract properly, and believing that the gear was in the down and locked position, the pilot elected to proceed to the destination airport. After touching down and rolling out on the main landing gear wheels, the nose landing gear was then lowered onto the runway's surface. After the nose landing gear contacted the runway all three landing gear retracted. A post-accident examination of the airplane revealed that the landing gear retraction motor had separated from its rear bulkhead attachment. The component's rivets were fractured in the contact surface plane, with deformation and smeared features observed to be consistent with overstress. It could not be determined when the overstress event occurred. ## Factual narrative On August 18, 2006, approximately 1905 Pacific daylight time, a Piper PA-24-250, N6249P, sustained substantial damage following the collapse of its main and nose landing gear during the landing roll at the Auburn Municipal Airport (S50), Auburn, Washington. The private pilot and his two passengers were not injured. Visual meteorological conditions prevailed for the personal flight, which was conducted in accordance with 14 CFR Part 91, and an instrument flight rules (IFR) flight plan was filed. The flight departed the Astoria Regional Airport (AST), Astoria, Oregon, about 1800, with its destination being S50. According to the Pilot/Operator Aircraft Accident/Incident Report (NTSB Form 6120.1), the pilot reported that after taking off from AST and following normal procedures to retract the landing gear, the gear did not retract. The pilot stated that he cycled the gear switch to the down position and that indications revealed the landing gear was down and locked. The pilot reported that he then elected to continue on his instrument flight rules (IFR) flight plan and proceed to S50, his destination airport. The pilot further reported that after he was cleared for the visual approach [to Runway 34] he closed his IFR flight plan and made a soft landing. The pilot stated that after the airplane touched down and rolled on its main wheels for about 50 to 75 feet, "...everything seemed normal." The pilot further stated that after the nose wheel touched the surface he could hear all three [landing] gear pop back up into the retracted position. The pilot reported, "...the prop started hitting the ground and then the fuselage settled and began sliding on the pavement. The only parts of the plane that touched the runway, other than the wheels, were the prop and the middle section of the belly." Two Federal Aviation Administration (FAA) aviation safety inspectors, who traveled to the accident site, reported that the firewall had sustained substantial damage. The inspectors also reported that there was damage to the fuselage skin on the underside of the airplane. A post-accident examination of the airplane revealed that the landing gear retraction motor had separated from its rear bulkhead attachment. An examination of the gear retraction motor attachment by an NTSB Materials Laboratory Senior Metallurgist, using an optical stereomicroscope, revealed that all rivets were fractured in the contact surface plane and had deformation and smeared features consistent with overstress fracture in shear. It could not be determined when the overstress event occurred. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, takeoff - initial climb - landing gear,normal retraction/extension assembly - overload (cause) - Gear collapsed, landing - roll - terrain condition - runway ## Aircraft - Registration: [N6249P](https://openairdocs.org/aircraft/N6249P), registered now, S/N 24-1356, built 1959 (OpenAirDocs) - Reported make and model: Piper PA-24-250 - Registry model: [Piper PA-24-250](https://openairdocs.org/model/piper-pa-24-250) (registry code 7102404) (OpenAirDocs) - Registry engine: [Lycoming 0-540 series](https://openairdocs.org/engine/lycoming-0-540-series) (registry code 41532, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 24-1356 - Airframe hours: 5061 - Engines: Lycoming O-540-A1C5 250 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, November 1, 2005 - Departed: AST, Astoria, OR - Destination: S50, Auburn, WA - Flight plan: IFR - Airport: S50, Auburn Municipal Airport, runway 34, 3,400 × 75 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 35; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, without waivers/limitations; last flight review September 1, 2005; seat: left; flight hours: 315 total, 178 in this make and model, 286 as pilot in command, 16 in the last 90 days, 7 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 350° at 11 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 36 °F, dew point 48 °F - Altimeter: 30.04 inHg - Observed at: SEA, 8 nm away ## 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 20060819017689A](https://openairdocs.org/incident/20060819017689A), Aug 19, 2006: Piper PA24250, Auburn, WA, Substantial damage. (-23) Aircraft sustained substantial damage following the collapse of its main and nose landing gear during landing roll. ## Docket (1 files) The files NTSB released with the investigation on November 29, 2006, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=64428. 452 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 452 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40269457&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date; 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.