Ennis - Big Sky Airport
Aircraft Accident/Incident Report

Ennis, Montana 59729
Monday, June 5, 2006 19:00 MDT

NTSB Narrative Summary Released at Completion of Accident

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.

NTSB Probable Cause Narrative

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.

Event Information

Type of Event Accident
Event Date 6/5/2006
Event Day of the Week Monday
Time of Event 1900
Event Time Zone Mountain Daylight Time
Event City Ennis
Event State MONTANA
Event Country --
Zipcode of the event site 59729
Event Date Year 2006
Event Date Month 6
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 451618N
Event Location Longitude 1113855W
Event Location Airport ENNIS - BIG SKY
Event Location Nearest Airport ID KEKS
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles 2
Degrees magnetic from airport --
Airport Elevation 5300
Weather Briefing Completeness --
Investigator's weather source Pilot
Time of the weather observation
Direction of event from weather observation facility (degrees) --
Weather Observation Facility ID --
Elevation of weather observation facility --
Distance of event from weather observation facility (units?) --
Time Zone of the weather observation --
Lighting Conditions Day
Lowest Ceiling Height --
Lowest Non-Ceiling Height --
Sky/Lowest/Cloud Conditions Clear
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) --
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) 180
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) 10
Wind Velocity Indicator --
Wind Gust Indicator Unknown
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) --
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal --
Injury Total Minor --
Injury Total None 4
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 21138
NTSB Notification Source FAA-ROC
NTSB Notification Date Jun 5 2006 12:00AM
NTSB Notification Time --
Fiche Number and/or location -used to find docket information DMS
Date of most recent change to record Mar 26 2007 9:33AM
User who most recently changed record NTSB\lema
Basic weather conditions Visual Meteorological Cond
FAA District Office Helena, Montana FSDO

Aircraft Involved

Aircraft #1

Aircraft Registration Number N24BF
NTSB Number SEA06LA114
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Beech
Aircraft Model A36
Aircraft Series Identifier --
Aircraft Serial Number E1736
Certified Max Gross Weight 3600
Aircraft Category Airplane
Aircraft Registration Class --
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 6
Number of Engines 1
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection Annual
Date of Last Inspection Mar 1 2006 12:00AM
Airframe hours since last inspection 35
Airframe Hours 3465
ELT Installed Yes
ELT Activated --
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name David A. Nicely
Aircraft Owner Street Address --
Aircraft Owner City Mission Hills
Aircraft Owner State KS
Aircraft Owner Country USA
Aircraft Owner Zipcode 66208
Operator is an individual? No
Operator Name --
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address --
Operator City --
Operator State --
Operator Country --
Operator Zip code --
Operator Code --
Owner has at least one certificate None
Other Operator of large aircraft? --
Certified for Part 133 or 137 Operation --
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not --
Indicates Domestic or International Flight --
Operator carrying Pax/Cargo/Mail --
Type of Flying (Per_Bus / Primary) Personal
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code KEKS
Departure City Ennis
Departure State MT
Departure Country USA
Departure Time 1700
Departure Time Zone MDT
Destination Same as Local Flt --
Destination Airport Code 6S5
Destination City HAMILTON
Destination State MT
Destination Country USA
Specific Phase of Flight Descent - emergency
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 31 2007 5:34PM
User who most recently changed record STAM
Since inspection or accident Last Inspection
Event Location Runway Number and Location 16
Runway Length 4694
Runway Width 75
Sight Seeing flight No
Air Medical Flight No
Medical Flight --