# NTSB WPR16LA174: Schneider K/Cook C SC Skybolt, N300SB, Corvallis, OR, August 24, 2016 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: August 24, 2016, 15:00 local (22:00 UTC) - Place: Corvallis, OR - Coordinates: 44.49472, -123.29083 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=44.4947&lon=-123.2908&mi=10 - Phase of flight: [Taxi](https://openairdocs.org/ntsb-phases/250) (OpenAirDocs' grouping) - Defining event: [Taxi: 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 3 - NTSB office: Western Pacific Region - Parties: FAA Portland FSDO - NTSB case key (mKey): 93973 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR16LA174 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/93973/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=93973 - Page: https://openairdocs.org/ntsb/WPR16LA174 ## Probable cause The collapse of the left main landing gear truss due to a weld joint failure, which resulted in substantial damage to the fuselage frame structure. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Landing gear system: main landing gear](https://openairdocs.org/ntsb-findings/01023210): Aircraft › Aircraft systems · Fatigue/wear/corrosion (probable cause); cases with it: [Schneider K/Cook C SC SKYBOLT, 1 case](https://openairdocs.org/ntsb-findings/01023210/cases.md?model=05623YB), [All aircraft, 241 cases](https://openairdocs.org/ntsb-findings/01023210/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Taxi: Landing gear collapse](https://openairdocs.org/ntsb-events/094) (defining event); cases with it: [Schneider K/Cook C SC SKYBOLT, 1 case](https://openairdocs.org/ntsb-events/094/sequence.md?model=05623YB), [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md) ## Analysis The father of the passenger reported that his son, who was the passenger and owner, had just purchased the airplane, that a prepurchase inspection was conducted, and that “everything looked good.” The pilot was conducting a personal, local flight in the airplane, which included normal maneuvers and several touch-and-go landings with no issues. However, after the last landing and while taxiing the airplane back to the ramp, the left main landing gear (MLG) collapsed. Examination of the left MLG’s truss structure, which is welded to the fuselage, revealed substantial damage to the fuselage frame structure. Examination also revealed that a weld joint where the truss mounts to the fuselage was cracked and broken. Rust was noted around the weld area, and it appeared that a previous crack had been repaired. The father reported that the area of the failure was hidden behind the bungee and was not visible during the prepurchase inspection. Given the evidence, it is likely that the left main landing gear collapsed due to the weld joint failure. ## Factual narrative On August 24, 2016, about 1500 Pacific daylight time, an experimental, amateur-built Skybolt airplane, N300SB, was substantially damaged when it was involved in an accident near Corvallis, Oregon. The pilot and passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The father of the passenger, who was the owner, reported that his son had just purchased the airplane, that a prepurchase inspection was conducted, and that “everything looked good.” He said his son asked the pilot to fly with him because he had extensive experience in similar airplanes. The flight included normal maneuvers and several touch-and-go landings with no issues. However, after the last landing and as he was taxiing the airplane back to the ramp, the left main landing gear (MLG) collapsed. Examination of the MLG truss structure, which is welded to the fuselage, revealed substantial damage to the fuselage frame structure. Examination also revealed that a weld joint where the truss mounts to the fuselage was cracked and broken. Rust was noted around the weld area, and it appeared that a previous crack had been repaired. The father reported that the area of the failure was hidden behind the bungee and was not visible during the prepurchase inspection. ## Aircraft - Registration: [N300SB](https://openairdocs.org/aircraft/N300SB), registered now, S/N 001, built 1993 (OpenAirDocs) - Reported make and model: SCHNEIDER K/COOK C SC SKYBOLT (NO SERIES) - Registry model: [Schneider K/Cook C SC SKYBOLT](https://openairdocs.org/model/schneider-k-cook-c-sc-skybolt) (registry code 05623YB) (OpenAirDocs) - Registry engine: [Lycoming I0360 series](https://openairdocs.org/engine/lycoming-i0360-series) (registry code 41515, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 001 - Year built: 1993 - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Departed: CVO, Corvallis, OR - Destination: CVO, Corvallis, OR - Airport: CVO, Corvallis Muni ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 74; injuries: none; private; airplane ratings: single-engine land; medical: unknown; seat: rear; restraint: 5-point ## Weather - Conditions: Visual (VMC), Day - Wind: 20° at 9 knots, gusting 16 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 91 °F, dew point 45 °F - Altimeter: 30.07 inHg - Observed at: KCVO ## Docket (1 files) The files NTSB released with the investigation on March 3, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=93973. 117 KB in all. - Memorandum for record - telephone interview, pilot (item 1, PDF, 1 page, 117 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11949697&FileExtension=pdf&FileName=WPR16LA174%20Record%20of%20Conversation-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.