# NTSB WPR20LA239: Vans RV7, N514BS, Henefer, UT, July 26, 2020 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 3 · Limited · Final report - Date: July 26, 2020, 11:10 local (17:10 UTC) - Place: Henefer, UT - Coordinates: 40.986667, -111.529724 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=40.9867&lon=-111.5297&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 101671 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR20LA239 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/101671/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=101671 - Page: https://openairdocs.org/ntsb/WPR20LA239 ## Probable cause The total loss of engine power due to the separation of the idler gear shaft bolts as a result of improper installation, which allowed for the idler gear to become disengaged. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating): recip eng rear section](https://openairdocs.org/ntsb-findings/01058540): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Solberg Scott E VANS RV7, 1 case](https://openairdocs.org/ntsb-findings/01058540/cases.md?model=05617QG), [All aircraft, 42 cases](https://openairdocs.org/ntsb-findings/01058540/cases.md) - [Maintenance: installation](https://openairdocs.org/ntsb-findings/02062035): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Solberg Scott E VANS RV7, 1 case](https://openairdocs.org/ntsb-findings/02062035/cases.md?model=05617QG), [All aircraft, 371 cases](https://openairdocs.org/ntsb-findings/02062035/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Solberg Scott E VANS RV7, 1 case](https://openairdocs.org/ntsb-events/341/sequence.md?model=05617QG), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Landing-landing roll: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Solberg Scott E VANS RV7, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=05617QG), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot reported that during the flight, he switched fuel tanks and shortly after, the engine began to sputter. The pilot turned on the electric fuel boost pump and switched the fuel selector valve to the original position, and the engine began to operate normally. However, a short time later, the engine quit, and despite his attempts, he was unable to restore engine power. The pilot initiated a forced landing to a nearby road during which the left wing struck the ground, the airplane veered to the left, exited the surface of the road, and impacted rising terrain. Postaccident examination of the engine revealed that the crankshaft idler gear shaft was separated from its mount and the idler gear was disengaged from the crankshaft and camshaft. Fretting was observed within the area of the idler gear shaft mount. The idler gear shaft bolts were separated. No evidence of a locking plate or safety wire was observed. It’s likely that idler gear bolts had become loose due to improper installation, which allowed the idler gear shaft to shift and the idler gear to become disengaged from the crankshaft and camshaft, which would result in a loss of engine power. ## Factual narrative On July 26, 2020, about 1110 mountain daylight time, a Vans RV7, N514BS, was substantially damaged when it was involved in an accident near Henefer, Utah. The pilot sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that while flying at an altitude of about 10,000 ft mean sea level, he switched fuel tanks and shortly after, the engine began to sputter. The pilot turned on the electric fuel boost pump and switched the fuel selector valve to the original position, and the engine began to operate normally. However, a short time later, the engine began to sputter a second time. Despite his attempts, he was unable to restore engine power and initiated a forced landing to a nearby road. During landing, the left wing struck the ground, and the airplane veered to the left off the surface of the road and impacted rising terrain. Both wings and fuselage were structurally damaged. Examination of the Lycoming IO-540-C4B5 engine by a Federal Aviation Administration inspector revealed that the crankshaft idler gear shaft was separated from its mount and the idler gear was disengaged from the crankshaft and camshaft. The idler gear shaft bolts were separated with no locking tabs or safety wire present. Photos supplied by the inspector showed that both the left idler gear shaft bolt holes were elongated, and the entire mounting area was severely worn and exhibited areas of fretting. The left idler gear interconnects the crankshaft, camshaft, left magneto, and fuel pump drive gears. (See figure 1) Figure 1: View of the idler gear and idler gear shaft assembly. ## Aircraft - Registration: [N514BS](https://openairdocs.org/deregistered/N514BS-2023-06-26), registration cancelled 2023-06-26, S/N 70845, built 2005 (OpenAirDocs) - Reported make and model: Vans RV7 - Registry model: [Solberg Scott E VANS RV7](https://openairdocs.org/model/solberg-scott-e-vans-rv7) (registry code 05617QG) (OpenAirDocs) - Registry engine: [Lycoming IO-540 series](https://openairdocs.org/engine/lycoming-io-540-series) (registry code 41530, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 70845 - Year built: 2005 - Engines: Lycoming IO-540 reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, April 20, 2020 - Departed: KOGD, Ogden, UT - Destination: Heber City, UT - Equipment: Electronic multifunction display, Electronic flight bag or handheld device, ADS-B, Handheld GPS, Electronic primary flight display ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 66; injuries: minor; airline transport, flight instructor; airplane ratings: multi-engine land, single-engine sea; instrument ratings: airplane; medical: class 3, with waivers/limitations; last flight review June 1, 2020; seat: left; restraint: 4-point; flight hours: 21,000 total, 120 in this make and model, 13,000 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: 20° at 10 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 86 °F, dew point 43 °F - Altimeter: 30.15 inHg - Observed at: KOGD, 25 nm away ## 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 20200726011249A](https://openairdocs.org/incident/20200726011249A), Jul 26, 2020: Solberg Scott E VANS RV7, Henefer, UT, Substantial damage. On July 26, 2020 at approximately 1110L, on a leg from kogd to khcr, the pilot leveled off at 9,500? And selected the alternate fuel tank. Next he turned the… ## Docket (3 files) The files NTSB released with the investigation on June 29, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=101671. 7.0 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 6 pages, 1.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12621353&FileExtension=pdf&FileName=WPR20LA239%20JDC%20Point%20One-Rel.pdf - FAA email for engine examination findings (item 2, PDF, 1 page, 50 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12619989&FileExtension=pdf&FileName=faa%20exam%20email_Redacted-Rel.pdf - Photo array (item 3, PDF, 3 pages, 3 photos, 5.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12620945&FileExtension=pdf&FileName=Photo%20%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.