# NTSB ANC24LA082: Piper PA-22-150, N6815B, Sagwon, AK, August 25, 2024 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Limited · Final report - Date: August 24, 2024, 20:45 local (Aug 25, 2024, 04:45 UTC) - Place: Sagwon, AK - Coordinates: 69.6475, -148.3955 - Nearby events: https://openairdocs.org/map.md?lat=69.6475&lon=-148.3955&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-landing roll: Landing gear collapse](https://openairdocs.org/ntsb-events/094) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 4 - Basic report with no Prelim publish - NTSB office: Alaska Regional Office - Parties: FAA - NTSB case key (mKey): 195009 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC24LA082 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/195009/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=195009 - Page: https://openairdocs.org/ntsb/ANC24LA082 ## Probable cause A failure of the landing gear fitting at the fuselage attachment point to due to a poor weld joint. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Landing gear system: main landing gear attach sec](https://openairdocs.org/ntsb-findings/01023211): Aircraft › Aircraft systems · Failure (probable cause); cases with it: [Piper PA-22-150, 4 cases](https://openairdocs.org/ntsb-findings/01023211/cases.md?model=7102210), [All aircraft, 66 cases](https://openairdocs.org/ntsb-findings/01023211/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-landing roll: Landing gear collapse](https://openairdocs.org/ntsb-events/094) (defining event); cases with it: [Piper PA-22-150, 15 cases](https://openairdocs.org/ntsb-events/094/sequence.md?model=7102210), [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md) - [Landing-landing roll: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330); cases with it: [Piper PA-22-150, 6 cases](https://openairdocs.org/ntsb-events/330/sequence.md?model=7102210), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) ## Analysis The pilot stated he was landing on a remote, rough and uneven gravel bar in a tailwheel-equipped airplane. During the landing roll, the left wing suddenly dipped, and it subsequently struck the gravel bar, sustaining substantial damage. A postaccident examination revealed that the left main landing gear had separated. Examination of the separated landing gear revealed the fractured areas of the weld at the fuselage attachment point exhibited rounded, reflected features consistent with a lack of fusion. In addition, there were areas that were absent of weld material along the circumferential or peripheral area, consistent with a lack of fusion. According to maintenance records the weld was from a landing gear conversion about 11 years prior to the accident. ## Aircraft - Registration: [N6815B](https://openairdocs.org/aircraft/N6815B), registered now, S/N 22-4111, built 1956 (OpenAirDocs) - Reported make and model: PIPER PA-22-150 - Registry model: [Piper PA-22-150](https://openairdocs.org/model/piper-pa-22-150) (registry code 7102210) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 22-4111 - Year built: 1956 - Airframe hours: 2213 - Engines: Lycoming O-320 150 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, July 12, 2024 - Departed: Happy Valley, AK - Destination: Same as departure - Equipment: ADS-B, Electronic flight bag or handheld device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 27; injuries: none; airline transport, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review April 29, 2024; seat: left; restraint: 4-point; flight hours: 3,201 total, 110 in this make and model, 2,202 as pilot in command, 133 in the last 90 days, 56 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 270° at 12 knots - Visibility: 10 statute miles - Lowest ceiling: 2,800 ft broken - Temperature: 39 °F, dew point 36 °F - Altimeter: 29.76 inHg - Observed at: ASC, 33 nm away - METAR: PASC 250426Z 27012KT 10SM FEW010 BKN028 OVC048 04/02 A2976 RMK AO2 T00440022 PNO ## 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 20240824013099A](https://openairdocs.org/incident/20240824013099A), Aug 24, 2024: Piper PA-22-150, Sagwon, AK, Substantial damage. During the landing rollout on a gravel river bank, the left main landing gear collapsed causing the left wing and propeller to contact the ground. ## Docket (4 files) The files NTSB released with the investigation on May 29, 2025, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=195009. 14.6 MB in all. - Materials laboratory (item 1, PDF, 1 page, 65 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18071246&FileExtension=pdf&FileName=MOR%20Materials%20Laboratory-Rel.pdf - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 2, PDF, 11 pages, 11.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18032338&FileExtension=pdf&FileName=NTSB%206120_1_Redacted-Rel.pdf - Maintenance records (item 3, PDF, 7 pages, 2.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18070720&FileExtension=pdf&FileName=Log%20book%20pages%20for%20landing%20gear%20conversion_Redacted-Rel.pdf - Photos (item 4, PDF, 4 pages, 1.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18070491&FileExtension=pdf&FileName=Photos-Rel.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.