CEN21LA078 · Vans RV4
Vans RV4 · Accident: loss of engine power (partial) during takeoff
From Sherman Municipal Airport (KSWI) to an unrecorded destination
Event
- NTSB case
- CEN21LA078
- 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
- Event fatalities
- Unknown
- 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
Vans RV4
- Aircraft type
- Vans RV4
- 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
- N423WH
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Sherman Municipal Airport (KSWI), Sherman, TXTo not recorded
- Aircraft age
- About 23 years (built 1997)
- 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
- Takeoff · rejected takeoff
- 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
- Loss of engine power (partial)
- 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
No findings designated as a cause are recorded in the NTSB data yet.
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The pilot was practicing low approaches at a private grass airstrip and elected to land. He determined he would land too far down the runway and initiated a go-around. The engine initially responded, but the engine power then reduced to idle. He “pumped the throttle” two or three times, and the engine did not respond. He subsequently landed on the runway. The airplane overran the end of the runway and nosed over, which resulted in substantial damage to the rudder, elevator, and left wing.
Postaccident engine runs were conducted with the engine attached to the airframe. The engine started and attempts were made to increase engine rpm. The engine would sputter and lose power momentarily each time the throttle was advanced. During one engine run, the engine stopped when the throttle was advanced. During the final engine run, the engine would not shut down normally using the throttle and mixture control, but it shut down when the ignition was turned off.
The engine, airframe, and throttle body unit were examined, and no preimpact anomalies were noted. Functional testing of the throttle body unit could not be completed due to a lack of access to appropriate test equipment. The reason for the partial loss of engine power could not be determined based on the available evidence.
Probable cause
The partial loss of engine power for reasons that could not be determined based on the available evidence.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN21LA078
- Event ID
- 20201208102386
- Case number
- CEN21LA078
- 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, coordinates. 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: b4eb993e42d0ffafa19ff844e129108b53706c76b0c9d0c9de2126528b534868; retrieved 2026-09-16T13:28:18.776Z.