# NTSB SEA02LA089: Artic S-1B2, N69AG, Tumtum, WA, May 26, 2002 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 26, 2002, 13:50 local (20:50 UTC) - Place: Tumtum, WA - Coordinates: 47.863887, -117.783889 - Nearby events: https://openairdocs.org/map.md?lat=47.8639&lon=-117.7839&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report April 23, 2003 - Report: Approved by Office Director - Parties: FAA FSDO - NTSB case key (mKey): 54814 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA02LA089 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/54814/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=54814 - Page: https://openairdocs.org/ntsb/SEA02LA089 ## Probable cause The pilot's improper flare. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Hard landing, landing - flare/touchdown - proper descent rate - not maintained, pilot in command (cause) - Main gear collapsed, landing - flare/touchdown - landing gear,main gear attachment - overload (contributing factor) - Nose over, landing - roll ## Analysis The pilot departed from a meadow in the Arctic Aircraft S-1B2 "Arctic Tern," and after some local sightseeing returned for landing. He reported that just after touchdown he heard a "pop" and the landing gear collapsed. An FAA Inspector, who interviewed the pilot, reported that the pilot stated that upon touchdown the left main landing gear collapsed, the aircraft began skidding and then the right main landing gear collapsed. The aircraft then nosed over and came to a stop. The pilot reported that the landing site was a flat, dirt field. Metallurgical examination of the left landing gear attach fitting revealed fracture features and deformation typical of an overstress fracture under a combined torsion and bending load. There was no evidence of a pre-existing cracking condition at the fitting's separation surfaces. ## Factual narrative On May 26, 2002, approximately 1350 Pacific daylight time, an Arctic Aircraft S-1B2 "Arctic Tern," N69AG, owned, operated and being flown by a private pilot incurred substantial damage during touchdown in a field approximately five nautical miles southwest of Tumtum, Washington. The pilot and passenger were uninjured. Visual meteorological conditions prevailed and no flight plan had been filed. The flight, which was personal, was operated under 14 CFR 91 and the aircraft departed from a local site approximately 1100. An inspector assigned to the Federal Aviation Administration's Spokane Flight Standards District Office interviewed the pilot. The pilot reported that upon touchdown the left main landing gear collapsed, the aircraft began skidding and then the right main landing gear collapsed. The aircraft then nosed over and came to a stop. The pilot reported that he and his passenger departed from a meadow and after some local sightseeing he returned for landing. He further reported that "...just after touching down a noticeable "pop" was heard and the landing gear collapsed..." and that "...the terrain [at the landing site] was a flat dirt field..." (refer to attached NTSB Form 6120-1/2). The broken landing gear attach fitting was sent to the Safety Board where it underwent a brief metallurgical examination at the Board’s Materials Laboratory. The examination revealed fracture features and deformation typical of an overstress fracture under a combined torsion and bending load. No evidence of pre-existing cracking was noted (refer to attached report). ## Aircraft - Registration: [N69AG](https://openairdocs.org/aircraft/N69AG), registered now, S/N 1020 (OpenAirDocs) - Reported make and model: Artic Aircraft Corp. S-1B2 - Registry model: [Arctic S-1B2](https://openairdocs.org/model/arctic-s-1b2) (registry code 0790208) (OpenAirDocs) - Category: Airplane - Serial number: 1020 - Airframe hours: 1944 - Engines: Continental O-320-A2B 150 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Coxon, Allen B. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, August 28, 2001, 16 hours before - Departed: Tumtum, WA - Destination: Tumtum, WA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 44; injuries: none; private; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; last flight review March 5, 1999; seat: front; toxicology performed; flight hours: 205 total, 65 in this make and model, 38 in the last 90 days, 14 in the last 30 days, 7 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 150° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: 6,500 ft broken - Temperature: 66 °F, dew point 48 °F - Altimeter: 29.87 inHg - Observed at: DEW, 16 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 20020526011189A](https://openairdocs.org/incident/20020526011189A), May 26, 2002: Arctic S1B2, Tumtum, WA, No damage. (-23) Pilot alan coxon and passenger were landing at friends farm field, located approximately 5 NM southwest of Tumtum, WA. General meteorological conditions… ## Docket (3 files) The files NTSB released with the investigation on March 9, 2003, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=54814. 392 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 312 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40439806&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Supplement S (item 2, .PDF, 26 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40178005&FileExtension=.PDF&FileName=Supplement%20S-Master.PDF - Materials Laboratory 15 - Factual Report 03-020 left landing gear fitting (item 3, .PDF, 53 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40177510&FileExtension=.PDF&FileName=Materials%20Laboratory%2015%20-%20Factual%20Report%2003-020%20left%20landing%20gear%20fitting-Master.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.