WPR09CA152 · Kenneth K Knowles Sonex
Kenneth K Knowles Sonex · Accident: loss of engine power (total) during initial climb
From Cottonwood Airport (P52) to Cottonwood Airport (P52)
Event
- NTSB case
- WPR09CA152
- 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
Kenneth K Knowles Sonex
- Aircraft type
- Kenneth K Knowles SONEX
- 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
- N997KK
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Cottonwood Airport (P52), Cottonwood, AZTo Cottonwood Airport (P52), Cottonwood, AZ
- 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
- Initial climb
- 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 (total)
- Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
- Tree(s)
- 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
- Not determined › Not determined
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 experienced a total loss of engine power during the first takeoff of the newly completed homebuilt experimental airplane. The pilot attempted to restart the engine but was unsuccessful. He then executed a forced landing in an open field. During the landing sequence the airplane sustained substantial damage to the left wing when it struck scrub chaparral. Post examination of the airplane and engine by an FAA inspector did not reveal any pre-impact malfunctions that would explain the loss of power.
Probable cause
The loss of engine power for undetermined reasons.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR09CA152
- Event ID
- 20090318X82022
- Case number
- WPR09CA152
- 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: 5f12b17f858f8b723199f1fee6f403088e0ac87d56b3fd82d59c7210945a5ab6; retrieved 2026-09-15T10:51:02.319Z.