# NTSB CEN23LA327: Vans RV10, N730WL, Chouteau, OK, July 21, 2023

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Class 3 · Limited · Final report
- Date: July 21, 2023, 13:50 local (18:50 UTC)
- Place: Chouteau, OK · Field on private property.
- Coordinates: 36.175387, -95.329857 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=36.1754&lon=-95.3299&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Defining event: [Enroute-cruise: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340)
- Highest injury: Minor injuries
- Injuries: 2 minor
- Status: Completed
- Report: Approved by Office Director
- Investigation class: Class 3
- NTSB office: Central Region
- Parties: FAA Will Rogers FSDO
- NTSB case key (mKey): 192721
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN23LA327
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/192721/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=192721
- Page: https://openairdocs.org/ntsb/CEN23LA327

## Probable cause

The total loss of engine power as a result of a failed positive crankcase ventilation (PCV) valve and a subsequent impact with terrain.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Engine (reciprocating)](https://openairdocs.org/ntsb-findings/01058500): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Gipson William H RV-10, 1 case](https://openairdocs.org/ntsb-findings/01058500/cases.md?model=05627XZ), [All aircraft, 497 cases](https://openairdocs.org/ntsb-findings/01058500/cases.md)
- [Engine (reciprocating): recip eng liquid cooling](https://openairdocs.org/ntsb-findings/01058570): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Gipson William H RV-10, 1 case](https://openairdocs.org/ntsb-findings/01058570/cases.md?model=05627XZ), [All aircraft, 17 cases](https://openairdocs.org/ntsb-findings/01058570/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Enroute-cruise: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) (defining event); cases with it: [Gipson William H RV-10, 1 case](https://openairdocs.org/ntsb-events/340/sequence.md?model=05627XZ), [All aircraft, 820 cases](https://openairdocs.org/ntsb-events/340/sequence.md)
- [Enroute-cruise: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [Gipson William H RV-10, 1 case](https://openairdocs.org/ntsb-events/060/sequence.md?model=05627XZ), [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/sequence.md)
- [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Gipson William H RV-10, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=05627XZ), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md)
- [Landing: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Gipson William H RV-10, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=05627XZ), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md)

## Analysis

The amateur-built experimental airplane was in cruise flight when the pilot noticed that a red warning light in the cockpit was illuminated. The “oil pressure gauge” was “pegged” at 320°F. The pilot immediately reduced engine power and initiated a glide profile to “take all the load off the engine” so it could cool down. While setting up for the approach to land at the closest airport, the engine “seized up” and sustained a total loss of power. The pilot performed a forced landing to a flat grass field. The airplane sustained substantial damage to the fuselage and both wings. Postaccident examination of the experimental automotive engine revealed that the positive crankcase ventilation (PCV) valve had failed. The pilot reported that the failed PCV valve caused the engine to suck “too much oil” out of the crankcase and into the intake section. He additionally reported that over the “long slow climb” to the cruise altitude of 6,000 ft, this caused the oil level to get “too low,” eventually causing the oil to overheat, and that once the oil overheated, the engine then stopped operating.

## Factual narrative

On July 21, 2023, about 1350 central daylight time, a Van’s Aircraft RV-10 airplane, N730WL, sustained substantial damage when it was involved in an accident near Chouteau, Oklahoma. The pilot and the passenger sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal cross-country flight. The purpose of the flight was for the two occupants to travel in the amateur-built experimental airplane to the Experimental Aircraft Association AirVenture at the Wittman Regional Airport (OSH), Oshkosh, Wisconsin. The airplane stopped at the Muskogee-Davis Regional Airport (MKO), Muskogee, Oklahoma, where it was refueled with about 35 gallons of 100 low lead fuel. The airplane departed to the north and, after being established in cruise flight at 6,000 ft, the pilot, who is also the owner of the airplane, noticed that a red warning light in the cockpit was illuminated. He noticed “the oil pressure gauge” was “pegged” at 320°F. The pilot immediately reduced engine power and initiated a glide profile to “take all the load off the engine” so it could cool down. The pilot decided to land at the closest airport, which was the Mid-America Industrial Airport (H71), Pryor, Oklahoma. While setting up for the approach to runway 36, the engine “seized up” and sustained a total loss of power. The pilot performed a forced landing to a flat grass field about 3 miles south of the threshold for runway 36. The airplane came to rest upright, and both occupants were able to egress from the airplane without further incident. The airplane sustained substantial damage to the fuselage and both wings. The airplane was recovered from the field and the experimental General Motors LS-3 (V-8) automotive engine was examined. The examination revealed that the positive crankcase ventilation (PCV) valve had failed for undetermined reasons. The pilot reported that the failed PCV valve caused the engine to suck “too much oil” out of the crankcase and into the intake section. He additionally reported that over the “long slow climb” to the cruise altitude of 6,000 ft, this caused the oil level to get “too low,” eventually causing the oil to overheat, and that once the oil overheated, the engine then stopped operating.

## Aircraft

- Registration: [N730WL](https://openairdocs.org/aircraft/N730WL), registered now, S/N 40227 (OpenAirDocs)
- Reported make and model: VANS RV10 (NO SERIES EXISTS)
- Registry model: [Gipson William H RV-10](https://openairdocs.org/model/gipson-william-h-rv-10) (registry code 05627XZ) (OpenAirDocs)
- Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs)
- Category: Airplane, amateur-built
- Serial number: 40227
- Year built: 2009
- Airframe hours: 240
- Engines: General Motors LS-3 (V-8) 375 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: N730wl LLC
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Condition, July 2, 2022
- Departed: MKO, Muskogee-Davis Regional Airport, OK
- Destination: H71, Pryor, OK
- Equipment: ADS-B, Auto-pilot, Electronic flight bag or handheld device, Electronic primary flight display

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 67; injuries: minor; private; airplane ratings: single-engine land; medical: class 3, without waivers/limitations; last flight review June 26, 2023; seat: left; restraint: 4-point; flight hours: 178 total, 30 in this make and model, 100 as pilot in command, 23 in the last 90 days, 18 in the last 30 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 320° at 3 knots
- Visibility: 10 statute miles
- Lowest ceiling: 1,600 ft broken
- Temperature: 75 °F, dew point 73 °F
- Altimeter: 30.01 inHg
- Observed at: KGCM, 10 nm away
- METAR: KGCM 211835Z AUTO 32003KT 10SM BKN016 OVC022 24/23 A3001 RMK AO2

## 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 20230721009149A](https://openairdocs.org/incident/20230721009149A), Jul 21, 2023: Gipson William H RV-10, Chouteau, OK, Substantial damage. On Friday, July 21st, aircraft landed at muskogee airport at about 10:30 am due to weather blocking flight path. The destination was krcm - skyhaven airport…

## Docket (8 files)

The files NTSB released with the investigation on April 18, 2024, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=192721. 10.4 MB in all.

- Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16223758&FileExtension=pdf&FileName=NTSB%20Form%206120_1%20Redacted-Rel.pdf
- Accident photographs (item 2, PDF, 4 pages, 1.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16225043&FileExtension=pdf&FileName=Accident%20Photographs-Rel.pdf
- Record of conversation - pilot (item 3, PDF, 1 page, 67 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16447153&FileExtension=pdf&FileName=CEN23LA327%20Pilot%20MOR-Rel.pdf
- Additional information - airplane (item 4, PDF, 7 pages, 4.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16223967&FileExtension=pdf&FileName=Additional%20Information%20-%20Airplane%20Redacted-Rel.pdf
- Additional information - pilot (item 5, PDF, 7 pages, 418 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16224011&FileExtension=pdf&FileName=Additional%20Information%20-%20Pilot%20Redacted-Rel.pdf
- N730WL - ADS-B data (google earth - .kmz file) (item 6, KMZ, 66 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16224493&FileExtension=kmz&FileName=20230721_A9CD0A_522019345-Rel.kmz
- N730WL - ADS-B data (microsoft excel - .xlsx file) (item 7, XLSX, 2.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16223196&FileExtension=xlsx&FileName=20230721_A9CD0A_522019345_ADSB-Rel.xlsx
- Release of aircraft wreckage, NTSB form 6120.15 (item 8, PDF, 2 pages, 125 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16223152&FileExtension=pdf&FileName=N730WL%20Retention-Release-of-Wreckage-Form%20Redacted-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.

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