Beechcraft A36 N24BF

Summary

On 6 June 2006 at about 01:00 local time, a Beechcraft A36 registered N24BF was involved in an accident near Ennis, Montana, United States. 4 people were on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

6 June 2006 at 01:00

Classification

Accident

Location

Ennis, Montana, United States

Nearest airport

Ennis - Big Sky (KEKS)

Coordinates

45.2717, -111.6486

Aircraft

Beechcraft A36

Registration

N24BF

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Ennis → Hamilton

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

SEA06LA114

Nobody was injured.

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.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full 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.

Quoted verbatim from the NTSB record.