# NTSB CEN23LA344: Beech A36, N36900, Oberlin, KS, July 20, 2023 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 3 · Limited · Final report - Date: July 20, 2023, 12:36 local (17:36 UTC) - Place: Oberlin, KS - Coordinates: 39.671297, -100.64721 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=39.6713&lon=-100.6472&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Fuel starvation](https://openairdocs.org/ntsb-events/191) - Highest injury: Minor injuries - Injuries: 1 minor, 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: FAA Flight Standards - NTSB case key (mKey): 192781 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN23LA344 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/192781/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=192781 - Page: https://openairdocs.org/ntsb/CEN23LA344 ## Probable cause The blockage of the left fuel tank vent, which resulted in a total loss of engine power due to fuel starvation. Contributing to the accident of the pilot’s failure to use his checklist to address the loss of engine power. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Fuel system](https://openairdocs.org/ntsb-findings/01022800): Aircraft › Aircraft systems · Malfunction (probable cause); cases with it: [Beech A36, 6 cases](https://openairdocs.org/ntsb-findings/01022800/cases.md?model=1151604), [All aircraft, 181 cases](https://openairdocs.org/ntsb-findings/01022800/cases.md) - [Use of equip/info: use of checklist](https://openairdocs.org/ntsb-findings/02063030): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Beech A36, 8 cases](https://openairdocs.org/ntsb-findings/02063030/cases.md?model=1151604), [All aircraft, 336 cases](https://openairdocs.org/ntsb-findings/02063030/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330); cases with it: [Beech A36, 4 cases](https://openairdocs.org/ntsb-events/330/sequence.md?model=1151604), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) - [Enroute-cruise: Fuel starvation](https://openairdocs.org/ntsb-events/191) (defining event); cases with it: [Beech A36, 15 cases](https://openairdocs.org/ntsb-events/191/sequence.md?model=1151604), [All aircraft, 733 cases](https://openairdocs.org/ntsb-events/191/sequence.md) ## Analysis The pilot reported that while in cruise flight over a cloud layer, the engine lost power as if it were out of fuel. The pilot attempted to restore engine power by switching to the right fuel tank and activating the starter but was unsuccessful. As the airplane descended through the cloud layer, the pilot switched back to the left fuel tank and then focused his attention on maintaining airplane control. The airplane descended below the cloud layer and the pilot maneuvered the airplane for a forced landing to a road. During the forced landing, the airplane impacted terrain, resulting in substantial damage to the left wing and fuselage. Examination of the fuel system revealed that the fuel venting system on the left-wing fuel tank was obstructed by what appeared to be insect debris. No other anomalies were noted during the examination of the airframe and engine that would have precluded normal operations. The circumstances of the power loss are consistent with an interruption of fuel flow from the left fuel tank due to inadequate venting of the fuel tank. During the attempt to restore engine power, the pilot did not engage the auxiliary fuel pump as stated in the emergency procedures checklist, which may have aided in restoring engine power. ## Factual narrative On July 20, 2023, about 1236 central daylight time, a Beech A36 airplane, N36900, sustained substantial damage when it was involved in an accident near Oberlin, Kansas. The pilot was not injured and the passenger sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. About 0900 mountain daylight time, the airplane departed from Northeast Wyoming Regional Airport (GCC), Gillette, Wyoming, and was en route to Dalhart Municipal Airport (DHT), Dalhart, Texas. The pilot reported that while in cruise flight over a cloud layer near Oberlin, the airplane sustained a loss of engine power as if it were out of fuel. The pilot attempted to restore engine power by switching to the right fuel tank and activating the starter using the ignition key; however, the attempts to restart the engine were unsuccessful. As the airplane descended through the cloud layer, the pilot switched back to the left fuel tank and focused his attention on the airplane instruments to maintain airplane control. The airplane descended through the clouds and the pilot regained visual ground reference about 1,500 ft above ground level. The pilot maneuvered the airplane for a forced landing to a road. Upon touchdown the right main landing gear traveled onto the shoulder of the road and the airplane exited the road and collided with an embankment. The airplane sustained substantial damage to the left wing and fuselage. According to the Federal Aviation Administration inspector who responded to the accident, both fuel tanks had visible fuel and both fuel caps were attached and in place. The pilot reported that the loss of engine power was due to a broken fuel pump shaft. However, during the postaccident examination, the engine-driven fuel pump shaft and drive coupler were found to be intact. The fuel pump was operationally checked and no anomalies or malfunctions were noted with its operation. The National Transportation Safety Board performed a postaccident examination of the airframe and engine. The examination revealed an obstruction in the left tank fuel vent. The one-way check valve in the fuel vent was observed stuck in the closed position, not allowing air through. When the fuel vent line was pressure tested the obstruction became dislodged. Further examination of the check valve revealed debris inside consistent with insect debris (Figure 1). No other mechanical anomalies were noted during the examination that would have precluded normal operation. Figure 1: Left tank fuel vent check valve. The airplane manufacture’s emergency procedures checklist for an air start procedure after an inflight engine failure includes selecting the auxiliary fuel pump ON. The pilot did not engage the auxiliary fuel pump during his restart attempts. ## Aircraft - Registration: [N36900](https://openairdocs.org/aircraft/N36900), registered now, S/N E-1739, built 1980 (OpenAirDocs) - Reported make and model: BEECH A36 - Registry model: [Beech A36](https://openairdocs.org/model/beech-a36) (registry code 1151604) (OpenAirDocs) - Registry engine: [Continental IO-520 series](https://openairdocs.org/engine/continental-io-520-series) (registry code 17032, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: E-1739 - Year built: 1980 - Airframe hours: 3300 - Engines: Continental IO-520-BB 285 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 20, 2023, 7.25 hours before - Departed: GCC, Gillette, WY - Destination: KDHT, Dalhart, TX - Airport: OIN - Equipment: ADS-B, Onboard weather ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 75; private; airplane ratings: single-engine land; medical: basicmed; seat: left; flight hours: 3,500 total, 900 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 80° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: 3,200 ft broken - Temperature: 77 °F, dew point 64 °F - Altimeter: 30.31 inHg - Observed at: KOIN, 12 nm away - METAR: KOIN 201735Z AUTO 08004KT 10SM BKN032 OVC037 25/18 A3031 RMK AO1 T02510184,M ## 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 20230720010649A](https://openairdocs.org/incident/20230720010649A), Jul 20, 2023: Beech A36, Oberlin, KS, Substantial damage. At approximately 12:20 pm CST on 7/20/2023, a single engine Beech model A36 aircraft lost engine power while enroute from gillette, Wyoming to dalhart, Texas… ## Docket (8 files) The files NTSB released with the investigation on May 9, 2024, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=192781. 10.4 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 2.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16422084&FileExtension=pdf&FileName=6120%20CEN23LA344_Redacted-Rel.pdf - Pilot's statement (item 2, PDF, 1 page, 80 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16119639&FileExtension=pdf&FileName=Pilot%27s%20Statement-J.Donald%20Parker-Rel.pdf - Investigation photographs (item 3, PDF, 3 pages, 758 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16422940&FileExtension=pdf&FileName=Investigation%20Photos-Rel.pdf - Examination summary (item 4, PDF, 8 pages, 693 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16396060&FileExtension=pdf&FileName=Exam%20Summary%20N36900-Rel.pdf - Maintenance records airframe (item 5, PDF, 7 pages, 3.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16418926&FileExtension=pdf&FileName=N36900%20AC%20Log-min_Redacted-Rel.pdf - Maintenance records engine (item 6, PDF, 10 pages, 3.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16419313&FileExtension=pdf&FileName=N36900%20Eng%20Log-min_Redacted-Rel.pdf - Maintenance records propeller (item 7, PDF, 3 pages, 324 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16419076&FileExtension=pdf&FileName=N36900%20Prop%20Log_Redacted-Rel.pdf - Emergency checklist (item 8, PDF, 1 page, 82 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16422066&FileExtension=pdf&FileName=Emergency%20Checklist-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.