WPR09LA254 · Mooney M20J
Mooney M20J · Accident: loss of engine power (partial) during takeoff
From Healdsburg Municipal Airport (O31) to Charles M. Schulz Sonoma County Airport (STS)
Event
- NTSB case
- WPR09LA254
- 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
Mooney M20J
- Aircraft type
- Mooney M20
- 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
- N4718H
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Healdsburg Municipal Airport (O31), Healdsburg, CATo Charles M. Schulz Sonoma County Airport (STS), Santa Rosa, CA
- 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
- 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
- Aircraft › Aircraft power plant
- Not determined › Not determined
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
Prior to departure, the pilot performed an engine run-up and noted that the performance appeared to be normal. During the takeoff ground roll, the pilot reported that the airplane seemed sluggish. Shortly after the airplane lifted off the runway surface, the engine experienced a partial loss of power. The airplane began to buffet and the pilot lowered the nose to prevent a stall. The airplane was losing altitude and he maneuvered it for an off airport landing. After clearing power lines, he made the forced landing in a vineyard adjacent to the airport. During the post accident engine inspection no mechanical anomalies were noted that would have precluded normal operation.
Probable cause
A partial loss of engine power during the takeoff initial climb for undetermined reasons.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR09LA254
- Event ID
- 20090522X80141
- Case number
- WPR09LA254
- 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: d016c1baffefa6af01285121db43620b4ed04726a7d4cc1014ff4b2796713710; retrieved 2026-09-15T11:08:38.457Z.