# NTSB CEN21LA343: Stinson JR. SR, N81Y, Ripon, WI, July 29, 2021 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 3 · Limited · Final report - Date: July 29, 2021, 12:30 local (17:30 UTC) - Place: Ripon, WI - Coordinates: 43.861263, -88.803719 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=43.8613&lon=-88.8037&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: Minor injuries - Injuries: 1 minor, 3 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: FAA FSDO - NTSB case key (mKey): 103589 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN21LA343 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103589/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=103589 - Page: https://openairdocs.org/ntsb/CEN21LA343 ## Probable cause A total loss of engine power due to fuel starvation. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Fluids: fuel](https://openairdocs.org/ntsb-findings/01071010): Aircraft › Fluids/misc hardware · Fluid level (probable cause); cases with it: [Stinson JR. SR, 1 case](https://openairdocs.org/ntsb-findings/01071010/cases.md?model=8630406), [All aircraft, 1,695 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md) - [Aircraft](https://openairdocs.org/ntsb-findings/01050000): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Stinson JR. SR, 1 case](https://openairdocs.org/ntsb-findings/01050000/cases.md?model=8630406), [All aircraft, 151 cases](https://openairdocs.org/ntsb-findings/01050000/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 JR. SR, 1 case](https://openairdocs.org/ntsb-events/341/sequence.md?model=8630406), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) ## Analysis The pilot was in-bound to the destination airport when the engine lost total power. The pilot conducted a forced landing to a muddy field where the airplane nosed over and came to rest inverted. Examination of the airplane revealed substantial damage to the empennage. One fuel tank was empty and there was fuel staining on the soil. The pilot reported that the airplane should have had about 15 to 20 gallons of fuel remaining at the time of the accident. In a subsequent conversation, the pilot reported that the airplane had an “odd fuel system” and if the fuel level was low, the engine could experience fuel starvation due to decreased fuel pressure, to which he attributed the loss of engine power on the accident flight. ## Factual narrative On July 29, 2021, about 1230 central daylight time, a Stinson JR SR airplane, N81Y, was substantially damaged when it was involved in an accident near Ripon, Wisconsin. The pilot received minor injuries and the three passengers were not injured. The airplane was operated as a Title 14 Code of Federal Regulations 91 personal flight. The airplane was in-bound to the destination airport via a visual flight rules arrival procedure when the engine lost total power. The pilot conducted a forced landing to a muddy field where the airplane nosed over and came to rest inverted. The responding Federal Aviation Administration (FAA) inspector noted substantial damage to the empennage. The inspector also noted that the one fuel tank was empty and there was fuel staining on the soil. The pilot reported that the airplane should have had about 15 to 20 gallons of fuel remaining. He added that the carburetor was recently overhauled and that there might have been something wrong with the carburetor. In a subsequent conversation, the pilot reported that he believed that nothing was wrong with the carburetor, but the airplane had an “odd fuel system” and if the fuel level was low, the engine could experience fuel starvation due to decreased fuel pressure, to which he attributed the loss of engine power. ## Aircraft - Registration: [N81Y](https://openairdocs.org/aircraft/N81Y), registered now, S/N 8729, built 1933 (OpenAirDocs) - Reported make and model: STINSON JR. SR - Registry model: [Stinson JR. SR](https://openairdocs.org/model/stinson-jr-sr) (registry code 8630406) (OpenAirDocs) - Registry engine: [Lycoming R680-4P-B4](https://openairdocs.org/engine/lycoming-r680-4p-b4) (registry code 41542, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 8729 - Year built: 1933 - Airframe hours: 187 - Engines: Lycoming 680 reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, May 10, 2021 - Departed: Dekalb, IL - Destination: OSH, Oshkosh, WI - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 40; injuries: minor; private; airplane ratings: single-engine land; medical: class 3, without waivers/limitations; seat: left ## Weather - Conditions: Visual (VMC), Day - Wind: 90° at 8 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 72 °F - Altimeter: 29.94 inHg - Observed at: KOSH - METAR: KOSH 291653Z 09008KT 10SM SCT031 27/22 A2994 RMK AO2 SLP125 T02720217 ## 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 20210729012099A](https://openairdocs.org/incident/20210729012099A), Jul 29, 2021: Stinson JR. SR, Ripon, WI, Substantial damage. On July, 29, 2021 at approximately 1230 CST, while attempting to get to oshkosh (osh) Wisconsin for the [privacy data omitted], a 1933 Stinson Jr. Sr aircraft… ## Docket (3 files) The files NTSB released with the investigation on November 30, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=103589. 2.3 MB in all. - Maintenance record (excerpt) (item 1, PDF, 1 page, 772 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12737896&FileExtension=pdf&FileName=Annual_Redacted-Rel.pdf - Photos (item 2, PDF, 2 pages, 1.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12758858&FileExtension=pdf&FileName=Photo%202-Rel.pdf - Memo (item 3, PDF, 1 page, 205 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12759068&FileExtension=pdf&FileName=Memo-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.