# NTSB ERA22LA333: Stinson 108, N6020M, Batesburg, SC, July 23, 2022 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: July 23, 2022, 14:00 local (18:00 UTC) - Place: Batesburg, SC · Coordinates within about 75 feet of resting position of the airplane. - Coordinates: 33.92782, -81.59204 - Nearby events: https://openairdocs.org/map.md?lat=33.9278&lon=-81.5920&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO - NTSB case key (mKey): 105557 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA22LA333 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/105557/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=105557 - Page: https://openairdocs.org/ntsb/ERA22LA333 ## Probable cause The fatigue failure of the crankshaft gear, resulting in a total loss of engine power. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating): recip eng rear section](https://openairdocs.org/ntsb-findings/01058540): Aircraft › Aircraft power plant · Fatigue/wear/corrosion (probable cause); cases with it: [Stinson 108-3, 1 case](https://openairdocs.org/ntsb-findings/01058540/cases.md?model=9230408), [All aircraft, 42 cases](https://openairdocs.org/ntsb-findings/01058540/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Stinson 108-3, 5 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=9230408), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Other: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Stinson 108-3, 5 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=9230408), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-landing roll: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Stinson 108-3, 15 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=9230408), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis Shortly after takeoff the engine sustained a total loss of engine power caused by fatigue failure of the crankshaft gear, necessitating the pilot to perform an off-airport forced landing that resulted in substantial damage. The fatigue fracture initiated from multiple origins at a corner of a keyway cut in the gear. The crankshaft gear underwent magnaflux inspection and was approved for return to service associated with an engine overhaul nearly 8 years and 247 hours earlier. While there was no evidence of plating at the fatigue initiation site, it could not be determined from the available evidence whether the fatigue existed in the part at the last inspection or how fast the fatigue crack was growing. ## Factual narrative On July 23, 2022, about 1400 eastern daylight time, a Stinson 108-3, N6020M, was substantially damaged when it was involved in an accident near Batesburg, South Carolina. The private pilot and a passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot stated that during cruise flight, while flying about 2,300 ft above mean sea level, the engine “went dead.” He made a forced landing to a field, and after touchdown the airplane collided with trees that bordered the field. Postaccident examination of the engine following recovery of the airplane revealed no valvetrain continuity with rotation of the crankshaft. Partial disassembly of the engine revealed that the crankshaft gear was fractured. Examination of the crankshaft gear by the National Transportation Safety Board Materials Laboratory revealed it failed due to fatigue that initiated from multiple origins at a corner of a keyway cut in the gear. There was no plating at the fatigue initiation site. A review of the maintenance records revealed a nearly 15-year gap in entries, and then the engine was overhauled by an airframe and powerplant mechanic on June 18, 2014, and installed on the airframe on June 1, 2016. Further review of the maintenance records associated with the engine overhaul revealed the crankshaft gear was magnafluxed and approved for return to service on April 25, 2012. Since installation, the engine remained installed in the airframe and underwent routine inspections and maintenance, accruing about 247 hours since major overhaul at the time of the accident. ## Aircraft - Registration: [N6020M](https://openairdocs.org/aircraft/N6020M), registered now, S/N 108-4020, built 1947 (OpenAirDocs) - Reported make and model: STINSON 108 (3) - Registry model: [Stinson 108-3](https://openairdocs.org/model/stinson-108-3) (registry code 9230408) (OpenAirDocs) - Registry engine: [Franklin 6A4165 series](https://openairdocs.org/engine/franklin-6a4165-series) (registry code 27025, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 108-4020 - Year built: 1947 - Airframe hours: 3147 - Engines: Franklin 6A4-165-B3 165 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 13, 2022, 9 hours before - Departed: 6J4, Saluda, SC - Destination: CUB, Columbia, SC - Equipment: Electronic flight bag or handheld device, ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 75; injuries: none; private; airplane ratings: single-engine land; medical: basicmed; last flight review May 29, 2022; seat: left; restraint: 3-point; flight hours: 590 total, 250 in this make and model, 519 as pilot in command, 2 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: 200° at 6 knots - Visibility: 10 statute miles - Temperature: 91 °F, dew point 73 °F - Altimeter: 30.15 inHg - Observed at: KAIK, 17 nm away - METAR: KAIK 231755Z AUTO 20006KT 10SM SCT044 33/23 A3015 RMK AO2 T03260228 10328 20245 ## 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 20220723013039A](https://openairdocs.org/incident/20220723013039A), Jul 23, 2022: Stinson 108-3, Batesburg Leesv, SC, Substantial damage. FAA form 8020-9: [privacy data omitted] An S108 was flying VFR squawking 1200, not talking to ATC. The aircraft lost his engine and could not get it to… ## Docket (8 files) The files NTSB released with the investigation on January 31, 2024, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=105557. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 11.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14256606&FileExtension=pdf&FileName=NTSB%20N6020M%20weh_Recd%208%201%202022_Redacted-Rel.pdf - Excerpts from engine logbook (item 2, PDF, 10 pages): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16460094&FileExtension=pdf&FileName=Excerpts%20Fm%20Engine%20Logbook_Redacted-Rel.pdf - FAA 8130-3 form regarding crankshaft gear (item 3, PDF, 1 page, 1.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16460229&FileExtension=pdf&FileName=Crankshaft%20Gear%20Yellow%20Tag_Redacted-Rel.pdf - Record of NTSB conversation (item 4, PDF, 2 pages, 166 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15421399&FileExtension=pdf&FileName=Record%20of%20NTSB%20Conversation_Redacted-Rel.pdf - Memorandum for record - engine examination results (item 5, PDF, 4 pages, 4 photos, 875 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16460136&FileExtension=pdf&FileName=Memo%20For%20Record%20-%20Engine%20Examination%20Results-Rel.pdf - Materials laboratory factual report 23-057 (item 6, PDF, 5 pages, 902 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15818274&FileExtension=pdf&FileName=23-057%20-%20gear-Rel.pdf - Investigative photographs (item 7, PDF, 5 pages, 5 photos, 5.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16460040&FileExtension=pdf&FileName=Investigative%20Photographs-Rel.pdf - Release of aircraft wreckage, NTSB form 6120.15, and NTSB evidence control forms (item 8, PDF, 4 pages, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15847441&FileExtension=pdf&FileName=Wreckage%20Release%20and%20ECF%27s_Redacted-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.