# NTSB SEA98LA162: Cessna T337E, N78SC, Hillsboro, OR, August 13, 1998 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: August 13, 1998, 10:15 local (17:15 UTC) - Place: Hillsboro, OR - Coordinates: 45.580642, -122.909286 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=45.5806&lon=-122.9093&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report February 15, 2001 - Report: Approved by Office Director - ADs cited in the narratives: [AD 87-20-03 R2](https://openairdocs.org/ad/87-20-03-R2) (OpenAirDocs) - NTSB case key (mKey): 43736 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA98LA162 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/43736/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=43736 - Page: https://openairdocs.org/ntsb/SEA98LA162 ## Probable cause The disengagement of the pilot seat forward and aft movement locking pin, followed by the pilot's seat sliding to the rear of the seat track. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, landing - flare/touchdown - miscellaneous,dowel/pin - disengaged (cause) - Loss of control - in flight, landing - flare/touchdown - fuselage,seat - slipped (cause) ## Analysis While attempting a touch-an-go landing, the pilot's seat locking pin disengaged, allowing the seat to slide to its full aft position. As the pilot tried to get his seat forward while holding onto the control yoke, the aircraft rolled to the left and impacted the terrain. During the investigation it was determined that AD 87-20-03 R2 (seat track visual inspection) had been signed off as complied with on 12/18/97, as part of the last annual inspection. The seat track and locking pin were also inspected by the FAA Airworthiness Inspector who responded to the accident, with no discrepancies found. ## Factual narrative On August 13, 1998, approximately 1015 Pacific daylight time, a Cessna T337E, N78SC, impacted the terrain between the runway and the taxiway at Portland-Hillsboro Airport, Hillsboro, Oregon. The private pilot, who was the sole occupant, received minor injuries, and the aircraft, which was owned and operated by the pilot, sustained substantial damage. The 14 CFR Part 91 proficiency flight, which was being conducted in the traffic pattern, was being operated in visual meteorological conditions. No flight plan had been filed, and the ELT, which was set off by the impact, was turned off at the scene. According to the pilot, he had done a number of touch-and-go landings with no indication of any problem. But, while he was in the flare for another landing, the pilot's seat forward and aft movement locking pin disengaged, and his seat slid to its full aft position. As the seat began to move aft, the pilot grabbed the control wheel in his left hand and "...apparently moved the control wheel to the left." As the aircraft was rolling to the left, the pilot was able to move his seat forward, but he was unable to roll the aircraft back to a wings-level attitude prior to impacting the terrain. During the investigation it was determined that AD 87-20-03 R2 (seat track visual inspection) had been signed off as complied with on 12/18/97, as part of the last annual inspection. The seat track and locking pin were also inspected by the FAA Airworthiness Inspector who responded to the accident, with no discrepancies found. ## Aircraft - Registration: [N78SC](https://openairdocs.org/deregistered/N78SC-2022-11-05), registration cancelled 2022-11-05, S/N 33701235, built 1970 (OpenAirDocs) - Reported make and model: Cessna T337E - Registry model: [Cessna T337E](https://openairdocs.org/model/cessna-t337e) (registry code 2075723) (OpenAirDocs) - Registry engine: [Continental TSIO-360 series](https://openairdocs.org/engine/continental-tsio-360-series) (registry code 17019, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 33701235 - Airframe hours: 3000 - Engines: Continental TSIO-360 210 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Cyr, Steven M. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, January 23, 1998, 60 hours before - Departed: HIO - Airport: HIO, Portland-Hillsboro, runway 30, 6,600 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 50; private; airplane ratings: single-engine land, multi-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 260 total, 60 in this make and model, 137 as pilot in command, 52 in the last 90 days, 17 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 70 °F ## 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 19980813020699A](https://openairdocs.org/incident/19980813020699A), Aug 13, 1998: Cessna T337E, Portland, OR, Substantial damage. Acft bounced on landing, lost control, and veered off the rwy. (-23)pilot stated that he had made a number of touch and go's. on the last touch and go, he… ## Docket (1 files) The files NTSB released with the investigation on October 1, 1998, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=43736. 1.6 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40423436&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, 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.