DEN01LA020 · Thomas VP-1
Thomas VP-1 · Accident: total loss of engine power (non-mechanical) during initial climb
From U42 to an unrecorded destination
Event
- NTSB case
- DEN01LA020
- 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
- 0
- 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
Thomas VP-1
- Aircraft type
- Thomas VP-1
- 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
- N89KD
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From U42To not recorded
- 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
- First occurrenceThe 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
- Total loss of engine power (non-mechanical)
- 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
- Terrain condition › None suitable
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot said he was flight-testing the newly finished homebuilt airplane. The original plans called for a fixed pitch propeller. The pilot said that he had put a manually adjustable pitch propeller on the airplane, and he had adjusted it for cruise flight. He said that once he was airborne, the engine began "lugging" and quickly lost power. He started a right turn to crosswind, and simultaneously began to perform a forced landing. Subsequently, the airplane struck a building and some transmission wires before coming to rest. Postaccident examination of the engine by an FAA inspector revealed that the spark plugs were wet with fuel. The inspector also found heavy carbon deposits in the exhaust stack.
Probable cause
the lack of suitable terrain for a forced landing. Contributing factors were the total loss of engine power due to the failure of the pilot to adjust the manual propeller pitch to permit the engine to achieve sufficient rpm for sustained flight, and the subsequent fouling of the spark plugs due to the over rich fuel condition.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record DEN01LA020
- Event ID
- 20001220X45452
- Case number
- DEN01LA020
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
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: 058588e71fce8e715272adbaf23df4af8503df0ebb7f6593ea36f35a26126bb5; retrieved 2026-09-21T10:18:09.341Z.