# NTSB CEN22LA315: Zenith Zodiac 650B, N452VC, Eufaula, OK, July 12, 2022 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: July 12, 2022, 10:00 local (15:00 UTC) - Place: Eufaula, OK - Coordinates: 35.282795, -95.589855 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=35.2828&lon=-95.5899&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: Central Region - Parties: FAA - NTSB case key (mKey): 105464 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN22LA315 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/105464/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=105464 - Page: https://openairdocs.org/ntsb/CEN22LA315 ## Probable cause The loss of engine power due to a push rod that was incorrectly installed by the airplane owner. ## 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 · Failure (probable cause); cases with it: [Valerie Westedt ZENITH ZODIAC 650B, 1 case](https://openairdocs.org/ntsb-findings/01058530/cases.md?model=05633VS), [All aircraft, 373 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md) - [Maintenance: installation](https://openairdocs.org/ntsb-findings/02062035): Personnel issues › Task performance · Owner/builder (probable cause); cases with it: [Valerie Westedt ZENITH ZODIAC 650B, 1 case](https://openairdocs.org/ntsb-findings/02062035/cases.md?model=05633VS), [All aircraft, 371 cases](https://openairdocs.org/ntsb-findings/02062035/cases.md) - [Engine (reciprocating): recip eng cyl section](https://openairdocs.org/ntsb-findings/01058530): Aircraft › Aircraft power plant · Incorrect service/maintenance (probable cause); cases with it: [Valerie Westedt ZENITH ZODIAC 650B, 1 case](https://openairdocs.org/ntsb-findings/01058530/cases.md?model=05633VS), [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. - [Enroute: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Valerie Westedt ZENITH ZODIAC 650B, 1 case](https://openairdocs.org/ntsb-events/341/sequence.md?model=05633VS), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Landing: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Valerie Westedt ZENITH ZODIAC 650B, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=05633VS), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis According to the pilots, who were both owners and builders of the airplane, while maneuvering during a local flight, the engine began to run rough. The engine power continued to decrease until they could not maintain altitude. Unable to reach a nearby airport, the pilot flying elected to perform an off-airport emergency landing. During the landing, the airplane impacted uneven terrain, which resulted in substantial damage to the right wing. Postaccident examination of the engine revealed the No. 5 cylinder exhaust valve rocker arm attach stud/bolt had failed. About 5 flight hours before the accident, the owners had replaced the No. 5 cylinder exhaust valve, which included the removal and reinstallation of the rocker arm hardware. The push rod contained an oil passage hole on one end that allowed for lubrication of the rocker arm, and the other end did not contain an oil passage. According to the owner, during the installation he incorrectly installed the push rod in a backward position. The incorrect installation did not allow lubrication to reach the rocker arm, causing it to fail. ## Factual narrative On July 12, 2022, about 1000 central daylight time, a Zenith 650B airplane, N452VC, sustained substantial damage when it was involved in an accident near Eufaula, Oklahoma. The pilot and pilot-rated passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to the pilots, who were both owners and builders of the airplane, while maneuvering during a local flight to adjust the airplane’s autopilot, the engine began to run rough. The engine power continued to decrease until they could not maintain altitude. Unable to make a nearby airport, the pilot flying elected to perform an off-airport emergency landing. During the landing, the airplane impacted uneven terrain, which resulted in substantial damage to the right wing. Postaccident examination of the Corvair conversion engine revealed the No. 5 cylinder exhaust valve rocker arm attach stud/bolt had failed (see Figure). No. 5 cylinder valve components (Photograph provided by the Federal Aviation Administration) About 5 flight hours before the accident, the owners had replaced the No. 5 cylinder exhaust valve, which included the removal and reinstallation of the rocker arm hardware. The push rod contained an oil passage hole on one end that allowed for lubrication of the rocker arm, and the other end did not contain an oil passage. According to the owner, during the installation he incorrectly installed the push rod in a backward position. ## Aircraft - Registration: [N452VC](https://openairdocs.org/aircraft/N452VC), registered now, S/N 65-8452, built 2015 (OpenAirDocs) - Reported make and model: ZENITH ZODIAC 650B - Registry model: [Valerie Westedt ZENITH ZODIAC 650B](https://openairdocs.org/model/valerie-westedt-zenith-zodiac-650b) (registry code 05633VS) (OpenAirDocs) - Registry engine: [Ulpower 350I](https://openairdocs.org/engine/ulpower-350i) (registry code 62001, 4 cycle) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 65-8452 - Year built: 2015 - Airframe hours: 285 - Engines: Westedt Corvair Conversion 110 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, June 15, 2022, 13 hours before - Equipment: Auto-pilot, ADS-B, Electronic multifunction display, Onboard weather, Handheld GPS, Electronic primary flight display ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 74; injuries: none; private; airplane ratings: single-engine land; medical: sport pilot, with waivers/limitations; last flight review November 29, 2021; seat: left; restraint: 3-point; flight hours: 444 total, 51 in this make and model, 386 as pilot in command, 3 in the last 90 days, 2 in the last 30 days - Pilot-rated passenger; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: sport pilot, with waivers/limitations; last flight review June 19, 2021; seat: right; restraint: 3-point; flight hours: 888 total, 212 in this make and model, 805 as pilot in command, 5 in the last 90 days, 3 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 310° at 8 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 88 °F, dew point 68 °F - Altimeter: 29.96 inHg - Observed at: KGZL, 24 nm away - METAR: KGZL 121515Z AUTO 31008KT 280V350 10SM CLR 31/20 A2996 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 20220712012569A](https://openairdocs.org/incident/20220712012569A), Jul 12, 2022: Valerie Westedt ZENITH ZODIAC 650B, Eufala, OK, Substantial damage. At 1000 local on 7/12/2022, [privacy data omitted] experienced engine issues and subsequent failure before landing in a field. During the rollout landing, the… ## Other investigations on N452VC (1) 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. - [NTSB WPR26LA243](https://openairdocs.org/ntsb/WPR26LA243), Jul 5, 2026: Valerie Westedt Zenith Zodiac 650B (N452VC), Peyton, CO, substantial damage, investigation ongoing ## Docket (3 files) The files NTSB released with the investigation on November 15, 2023, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=105464. 6.4 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 4.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14335202&FileExtension=pdf&FileName=NTSB%20report_Redacted-Rel.pdf - Email correspondence - owner (item 2, PDF, 1 page, 122 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14333808&FileExtension=pdf&FileName=Email%20Owner_Redacted-Rel.pdf - Photo array (item 3, PDF, 4 pages, 1.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14334979&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.