# NTSB WPR21LA049: Ronald A Gawer RV-12, N975G, Byron, CA, November 6, 2020

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Class 3 · Limited · Final report
- Date: November 6, 2020, 11:58 local (19:58 UTC)
- Place: Byron, CA
- Coordinates: 37.823174, -121.62965 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=37.8232&lon=-121.6296&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Defining event: [Takeoff: 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: Western Pacific Region
- Parties: FAA FSDO
- NTSB case key (mKey): 102278
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR21LA049
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/102278/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=102278
- Page: https://openairdocs.org/ntsb/WPR21LA049

## Probable cause

The total loss of engine power due to a fatigue fracture of the crankshaft.

## Findings

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

- [Engine (reciprocating): recip engine power section](https://openairdocs.org/ntsb-findings/01058520): Aircraft › Aircraft power plant · Fatigue/wear/corrosion (probable cause); cases with it: [Ronald A Gawer RV-12, 1 case](https://openairdocs.org/ntsb-findings/01058520/cases.md?model=056344J), [All aircraft, 233 cases](https://openairdocs.org/ntsb-findings/01058520/cases.md)

## Sequence of events

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

- [Takeoff: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Ronald A Gawer RV-12, 1 case](https://openairdocs.org/ntsb-events/341/sequence.md?model=056344J), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md)
- [Emergency descent: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341); cases with it: [Ronald A Gawer RV-12, 1 case](https://openairdocs.org/ntsb-events/341/sequence.md?model=056344J), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md)
- [Landing-flare/touchdown: Loss of control on ground](https://openairdocs.org/ntsb-events/230); cases with it: [Ronald A Gawer RV-12, 1 case](https://openairdocs.org/ntsb-events/230/sequence.md?model=056344J), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md)
- [Landing-landing roll: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Ronald A Gawer RV-12, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=056344J), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md)

## Analysis

The pilot reported that after takeoff from runway 23, about 466 ft above ground level, the engine “failed,” and he immediately turned back to land. The pilot landed with a direct gusting tailwind and applied hard braking; however, a gust of wind lifted the right wing, and the airplane exited the left side of the runway. The left wing struck a taxiway sign, which resulted in substantial damage to the left wing. A postaccident examination of the engine revealed that the crankshaft was fractured aft of the No. 2 connecting rod journal. The fracture surface exhibited signatures consistent with fatigue cracking that originated from multiple initiation sites along the radius between the connecting rod journal and the crankshaft web.

## Factual narrative

On November 6, 2020, about 1158 Pacific standard time, an experimental amateur-built Vans RV-12 airplane, N975G, was substantially damaged when it was involved in an accident near Byron, California. The pilot and passenger were uninjured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that after takeoff from runway 23, at approximately 466 ft above ground level, the engine failed, and he immediately initiated a left turn toward runway 5. The pilot stated that upon completing the 180° turn, he encountered a gusting tailwind, which increased his airspeed of 65 knots to a groundspeed of about 85 to 88 knots. Concerned he would run off the end of the runway, he landed, “braked hard, and was slowing [the airplane] straight on the runway”when a gust of wind lifted the right wing, and the airplane exited the left side of the runway. The left wing struck a taxiway sign, the nose gear sheared off resulting in substantial damage to the left wing. The pilot reported that at the time of takeoff, the wind was from 230° at 18 knots with gusts to 23 knots. A postaccident examination of the UL Power UL350iS engine revealed that the crankshaft was separated aft of the No. 2 connecting rod and forward of the No. 3 main bearing journal. The separated portions of the crankshaft were sent to the National Transportation Safety Board Materials Laboratory for further examination. The examination revealed the crankshaft had fractured just aft of the No. 2 connecting rod journal and forward of the crankshaft web (see figure). Figure. – Crankshaft Ratchet marks, consistent with multiple crack initiation sites, were present particularly near the initial areas of the fracture, located along the edge of the fracture surface at the radius near the connecting rod journal surface. A series of repeating crack arrest marks along with microscopic fatigue striations, consistent with fatigue crack propagation, was observed within the fracture surface. Additionally, the journal surface exhibited circumferentially oriented microscopic gouge marks, which were present up to the edge, as well as near one fatigue crack initiation site.

## Aircraft

- Registration: [N975G](https://openairdocs.org/deregistered/N975G-2022-11-05), registration cancelled 2022-11-05, S/N 120840, built 2018 (OpenAirDocs)
- Reported make and model: RONALD A GAWER RV-12 (NO SERIES)
- Registry model: [Ronald A Gawer RV-12](https://openairdocs.org/model/ronald-a-gawer-rv-12) (registry code 056344J) (OpenAirDocs)
- Registry engine: [Ulpower UL350IS](https://openairdocs.org/engine/ulpower-ul350is) (registry code 62000, 4 cycle) (OpenAirDocs)
- Category: Airplane, amateur-built
- Serial number: 120840
- Year built: 2018
- Engines: ULPOWER UL350IS 130 horsepower; 
- Damage: Substantial damage
- Flight: Personal, Part 91
- Airworthiness certificate: Standard, Normal; Special, Experimental (Special)
- Last inspection: Annual, May 17, 2020
- Destination: Same as departure
- Airport: C83, Byron Airport, runway 23, 3,000 × 75 ft, asphalt
- Equipment: ADS-B, Stall warning system, Electronic primary flight display, Electronic multifunction display, Electronic flight bag or handheld device, Auto-pilot, Angle of attack indicator

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 57; injuries: none; private; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: basicmed, without waivers/limitations; seat: left; restraint: 5-point; flight hours: 2,204 total, 439.5 in this make and model, 2,138.6 as pilot in command, 11.6 in the last 90 days, 3.7 in the last 30 days, 0 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 240° at 15 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 61 °F, dew point 37 °F
- Altimeter: 29.78 inHg
- Observed at: KLVK, 12 nm away
- METAR: KLVK 061953Z COR 24015KT 10SM SCT030 16/03 A2978 RMK AO2 SLP083 T01560028

## 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 20201106019089A](https://openairdocs.org/incident/20201106019089A), Nov 6, 2020: Ronald A Gawer RV-12, Byron, CA, Substantial damage. The accident occurred on November 6, 2020 at approximately 1225. Aircraft is an experimental homebuilt RV-12, registration as N975G. Aircraft took off from…

## Docket (6 files)

The files NTSB released with the investigation on June 7, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=102278. 15.8 MB in all.

- Materials laboratory factual report (item 1, PDF, 16 pages, 17 photos, 5.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12248751&FileExtension=pdf&FileName=21-028%20-%20Materials%20Lab%20Factual%20Report%20(WPR21LA049)-Rel.pdf
- Pilot/operator aircraft accident report, NTSB form 6120.1 (item 2, PDF, 9 pages, 580 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12650612&FileExtension=pdf&FileName=NTSB%20Form%206120_1%20N975G%20Signed_Redacted-Rel.pdf
- Meteorology (item 3, PDF, 1 page, 231 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12573588&FileExtension=pdf&FileName=WX-Rel.pdf
- FAA inspector's statement (item 4, PDF, 2 pages, 57 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13159127&FileExtension=pdf&FileName=FAA%20narrative-Rel.pdf
- Roc FAA FSDO exam summary (item 5, PDF, 6 pages, 151 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13184929&FileExtension=pdf&FileName=Record%20of%20Conversation%20Email%20FAA%20FSDO%20Eng%20Exam-Rel.pdf
- Photos (item 6, PDF, 10 pages, 9.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12573212&FileExtension=pdf&FileName=N975G%20Photos%20WPR21LA049-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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