# NTSB WPR22LA316: Cessna 150H, N22507, Vacaville, CA, August 24, 2022 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 3 · Limited · Final report - Date: August 24, 2022, 11:18 local (18:18 UTC) - Place: Vacaville, CA - Coordinates: 38.370146, -121.96546 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=38.3701&lon=-121.9655&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: 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: Western Pacific Region - Parties: Federal Aviation Adminsitration - NTSB case key (mKey): 105794 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR22LA316 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/105794/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=105794 - Page: https://openairdocs.org/ntsb/WPR22LA316 ## Probable cause The partial loss of engine power due to a stuck exhaust valve. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating): recip eng cyl section](https://openairdocs.org/ntsb-findings/01058530): Aircraft › Aircraft power plant · Malfunction (probable cause); cases with it: [Cessna 150H, 2 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md?model=2071818), [All aircraft, 373 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Initial climb: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) (defining event); cases with it: [Cessna 150H, 1 case](https://openairdocs.org/ntsb-events/340/sequence.md?model=2071818), [All aircraft, 820 cases](https://openairdocs.org/ntsb-events/340/sequence.md) - [Initial climb: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342); cases with it: [Cessna 150H, 4 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=2071818), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Cessna 150H, 13 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=2071818), [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: [Cessna 150H, 27 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=2071818), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot was conducting a personal flight. During the initial climb after takeoff, the engine lost partial power, and the airplane was unable to maintain altitude. The pilot initiated a forced landing to a nearby field; during the landing roll, the airplane impacted uneven terrain and came to rest upright, which resulted in substantial damage to the left wing and fuselage. Postaccident examination of the engine revealed that the No. 2 cylinder exhaust valve exhibited signatures consistent with a stuck valve, including a buildup of carbon deposits, and the exhaust valve could only be moved out of the valve guide with a significant amount of force. No additional evidence indicated any pre-existing mechanical malfunction or failure that would have precluded normal operation. Thus, the stuck exhaust valve likely caused the partial loss of engine power. ## Factual narrative On August 24, 2022, about 1118 Pacific daylight time, a Cessna 150H, N22507, was substantially damaged when it was involved in an accident near Nut Tree Airport (VCB), Vacaville, California. The pilot and passenger sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that, during the initial climb after takeoff from runway 20 at VCB, while the airplane was at an altitude of about 200 to 250 ft above ground level, the engine began to sputter, and the engine speed decreased to about 1,700 to 1,800 rpm. The pilot verified that the mixture and throttle were in the takeoff positions, but the airplane was no longer climbing, and the pilot had difficulty maintaining the airplane’s altitude. As a result, the pilot initiated a forced landing to an open field adjacent to the airport. During the landing roll, the airplane impacted uneven terrain and came to rest upright, resulting in substantial damage to the left wing and fuselage. Postaccident examination of the engine revealed that it was partially attached to the engine mount. The carburetor was separated from the intake spider. The upper spark plugs, and rocker box covers were removed, and the propeller was rotated by hand. Rotational continuity was established throughout the engine. Thumb compression was obtained on cylinder Nos. 1, 3, and 4. No compression was obtained on cylinder No. 2, which was removed for further examination. The No. 2 cylinder was intact and undamaged. The exhaust and intake valve springs were intact and oil coated, as were the intake and exhaust valve rocker arms. The valve springs and keepers were removed. The intake valve slid out of the valve guide freely, but the exhaust valve slid out of the valve guide with a significant amount of force. The exhaust valve stem exhibited carbon buildup along with the valve neck. White deposits were observed around the rim of the valve. The valve seat also exhibited carbon buildup. The intake valve stem exhibited carbon deposits on the neck of the valve and stem. The valve seat contact area showed no carbon buildup, but a slight amount of carbon build-up was observed on the valve rim. Examination of the airframe and engine revealed no additional evidence of pre-existing mechanical malfunction that would have precluded normal operation. ## Aircraft - Registration: [N22507](https://openairdocs.org/deregistered/N22507-2024-01-13), registration cancelled 2024-01-13, S/N 15068324, built 1968 (OpenAirDocs) - Reported make and model: CESSNA 150H - Registry model: [Cessna 150H](https://openairdocs.org/model/cessna-150h) (registry code 2071818) (OpenAirDocs) - Registry engine: [Continental 0-200 series](https://openairdocs.org/engine/continental-0-200-series) (registry code 17020, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 15068324 - Year built: 1968 - Airframe hours: 6976.6 - Engines: Continental Motors 0-200-A 100 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, August 11, 2022 - Destination: MCC, Sacramento, CA - Airport: VCB, Nut Tree Airport, runway 20, 4,700 × 75 ft, asphalt - Equipment: ADS-B, Electronic flight bag or handheld device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 28; injuries: minor; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review October 28, 2021; seat: left; restraint: 3-point; flight hours: 973 total, 370 in this make and model, 891 as pilot in command, 200 in the last 90 days, 114 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 170° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 84 °F, dew point 57 °F - Altimeter: 29.80 inHg - Observed at: KVCB, 1 nm away - METAR: KVCB 241753Z AUTO 17003KT 10SM CLR 29/14 A2980 RMK AO2 SLP091 T02940144 10294 20172 51004 ## 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 20220824017909A](https://openairdocs.org/incident/20220824017909A), Aug 24, 2022: Cessna 150H, Vacaville, CA, Substantial damage. A written statement from the pilot stated that he landed at the nut tree airport (kvcb) from the willows/glenn county airport (kwlw). He fueled up at kvcb and… ## Docket (3 files) The files NTSB released with the investigation on August 15, 2023, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=105794. 8.2 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 5.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15073009&FileExtension=pdf&FileName=6120_Redacted-Rel.pdf - Airframe and engine examination report (item 2, PDF, 3 pages, 1 photo, 197 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15073019&FileExtension=pdf&FileName=wreckage%20examination%20report-Rel.pdf - Photo array (item 3, PDF, 5 pages, 5 photos, 2.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15230003&FileExtension=pdf&FileName=photo%20array-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.