SEA06LA114 · Beech A36
Beech A36 · Accident: loss of engine power during takeoff
From Ennis Big Sky Airport (KEKS) to 6S5 · Hamilton, MT
Event
- NTSB case
- SEA06LA114
- 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
Beech A36
- Aircraft type
- Beechcraft 36
- 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
- N24BF
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Ennis Big Sky Airport (KEKS), Ennis, MTTo 6S5 · Hamilton, MT
- 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
- 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
- Loss of engine power
- 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
- Mixture control, linkage › Failure, partial
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 reported that shortly after takeoff the airplane lost engine power and he elected to land in an open field south of the airport. Post accident evaluation and testing of the mixture control linkage revealed that the metering shaft rotated to the mechanical stop when actuated to the "idle cut-off" position; however, when the mixture control was actuated to the "full-rich" position, the metering shaft rotated approximately 40 percent of potential (full) travel and did not reach the mechanical stop. Further examination revealed the mixture control arm retaining nut was tight, however extensive wear to the serrated mating surfaces of the mixture control arm and metering shaft was observed. The serrated edges had worn smooth and fretting type damage was noted to both surfaces. Maintenance records showed that the airplane's original engine, a Continental IO-520, was removed and the airframe was retrofitted with a factory rebuilt (zero time) IO-550-B in accordance with a Supplemental Type Certificate (STC). The certified airframe and power plant (A&P) mechanic, who performed the maintenance on the airplane, stated the mixture control arm (which was shipped with the engine) was installed in conjunction with the engine conversion.
Probable cause
The loss of engine power during takeoff due to an excessively lean fuel-to-air mixture ratio as a result of excessive mating surface wear between the mixture control arm and metering shaft. A factor was the improper installation of the new engine, which resulted in excessive wear and metering of fuel and loss of engine power. An additional factor was the rough, uneven terrain.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA06LA114
- Event ID
- 20060616X00753
- Case number
- SEA06LA114
- 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: local date, investigation status, coordinates. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2006-06-06.
- API snapshot SHA-256: 0b33bc0232a3e95ffccea741dd803b2830a87835dccc29cbdff159911a922e68; retrieved 2026-09-22T04:48:08.700Z.