ERA09LA477 · Vollenweider R/Hurst R F VANS RV-9A
Vollenweider R/Hurst R F VANS RV-9A · Accident: powerplant system/component malfunction/failure en route
From 1J0 · Bonifay, FL to 1J0 · Bonifay, FL
Event
- NTSB case
- ERA09LA477
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Vollenweider R/Hurst R F VANS RV-9A
- Aircraft type
- Vollenweider R/hurst VANS RV-9A
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N362TS
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From 1J0 · Bonifay, FLTo 1J0 · Bonifay, FL
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- En route · cruise
- Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Powerplant system/component malfunction/failure
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Aircraft › Aircraft propeller/rotor
- Not determined › Not determined
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The owner/pilot reported that, at an altitude of about 4,000 feet in his experimental amateur-built airplane equipped with a non-certificated propeller speed reduction unit (PSRU) gearbox, he heard a loud "bang." Although the engine continued to run normally and the pilot could control the engine rpm, the pilot determined that he was no longer obtaining thrust from the propeller. In his attempt to glide to an airport about 13 miles from the failure location, the pilot overflew multiple fields and sections of roadway that were suitable for an off-field landing. The airplane struck trees 3 miles short of the intended airport, and the pilot was seriously injured. Postaccident examination revealed that the PSRU gearbox had failed catastrophically, with the result that the engine was unable to transmit power to the propeller. Investigation revealed that the accident PSRU gearbox was the manufacturer's first generation version, referred to as "Gen-I." At the time of the accident, third-generation "Gen-III" gearboxes were current, and the manufacturer had previously determined and notified owners that replacement with the Gen-III version was mandatory. The pilot was aware of the manufacturer's mandate regarding the gearbox replacement, but based on cost and time-in-service reasons, he decided not to replace his Gen-I gearbox. While the gearbox manufacturer "mandated" that owners replace their previous model gearboxes, and his published information clearly stated that he had safety concerns about the previous model gearboxes, he was actually unable to force them to replace the gearboxes. Since the manufacturer did not provide the gearbox owners with substantiating data such as failure rates, time in service, or a catalog of failure events, gearbox owners could have concluded that the manufacturer's mandate was motivated by economic, instead of safety, reasons.
Probable cause
Failure of the propeller speed reduction gearbox for undetermined reasons. Contributing to the accident was the pilot’s decision to disregard the manufacturer's mandate to replace the gearbox, the manufacturer's failure to provide owners with technical substantiation for the replacement, and the pilot's decision to overfly several suitable off-field landing sites in an attempt to glide to a distant airport.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ERA09LA477
- Event ID
- 20090823X01951
- Case number
- ERA09LA477
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: d4e1078eeec365642091199d7fb5a9af49563aad4ff76ce7e1f38283fee1ed7c; retrieved 2026-09-15T12:50:01.241Z.