Aircraft Accident/Incident Report

Chinook, Montana 59523
Thursday, October 9, 2003 17:20 MDT

NTSB Narrative Summary Released at Completion of Accident

While in cruise flight the aircraft suddenly lost all engine power, and after unsuccessfully attempting to get the engine restarted, the pilot attempted a forced landing on a nearby gravel road. During that attempt, the pilot failed to adequately compensate for strong crosswinds, and therefore inadvertently clipped the top of a tree that was located immediately adjacent to the approach end of the section of road he was trying to land upon. A post-accident inspection of the engine determined that the carburetor had separated from the engine in cruise flight, due to the fact that there were no longer any nuts on any of the four carburetor mount retaining lug bolts. The carburetor mounting flange holes all remained intact, and none of the four mounting bolts showed any signs of damaged or distorted threads. Recent use of Marihuana was determined to have impaired the pilot's judgment at the time he was attempting the forced landing.

NTSB Probable Cause Narrative

The total loss of engine power in cruise flight due to the separation of the carburetor from its mounting bolts, and the pilot's failure to adequately compensate for strong crosswinds while attempting the subsequent forced landing. Additional factors include strong crosswinds, a tree immediately adjacent to the gravel road that the pilot chose to land on, and the pilot's impairment due to recent use of Marihuana.

Event Information

Type of Event Accident
Event Date 10/9/2003
Event Day of the Week Thursday
Time of Event 1720
Event Time Zone Mountain Daylight Time
Event City Chinook
Event State MONTANA
Event Country --
Zipcode of the event site 59523
Event Date Year 2003
Event Date Month 10
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 483037N
Event Location Longitude 1091627W
Event Location Airport --
Event Location Nearest Airport ID --
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation --
Weather Briefing Completeness Unknown
Investigator's weather source Witness
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) 18
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) 250
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) 13
Wind Velocity Indicator --
Wind Gust Indicator Gusting
Wind Gust (knots) 18
Altimeter Setting at event time (in. Hg) --
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report --
Event Highest Injury Fatal
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal 2
Injury Total Minor --
Injury Total None --
Injury Total Serious 1
Injury Total All 3
Investigating Agency NTSB
NTSB Docket Number (internal use) 16190
NTSB Notification Source FAA ROC
NTSB Notification Date Oct 9 2003 12:00AM
NTSB Notification Time 1700
Fiche Number and/or location -used to find docket information DMS
Date of most recent change to record Sep 1 2004 7:08AM
User who most recently changed record NTSB\MONR
Basic weather conditions Visual Meteorological Cond
FAA District Office Helena FSDO

Aircraft Involved

Aircraft #1

Aircraft Registration Number N30921
NTSB Number SEA04FA003
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? No
Damage Destroyed
Aircraft Fire Ground
Aircraft Explosion None
Aircraft Manufacturer's Full Name Cessna
Aircraft Model 177B
Aircraft Series Identifier --
Aircraft Serial Number 17701546
Certified Max Gross Weight 2500
Aircraft Category Airplane
Aircraft Registration Class U.S. Registered/U.S. Soil
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 4
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Annual
Date of Last Inspection Jun 5 2003 12:00AM
Airframe hours since last inspection --
Airframe Hours 3083
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name Michael D. Kirn
Aircraft Owner Street Address --
Aircraft Owner City Poplar
Aircraft Owner State MT
Aircraft Owner Country USA
Aircraft Owner Zipcode 59255
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 No
Departure Airport Code GTF
Departure City Great Falls
Departure State MT
Departure Country USA
Departure Time 1620
Departure Time Zone MDT
Destination Same as Local Flt --
Destination Airport Code 42S
Destination City Poplar
Destination State MT
Destination Country USA
Specific Phase of Flight Cruise
Report sent to ICAO? No
Evacuation occurred No
Date of most recent change to record Jun 23 2004 5:34PM
User who most recently changed record STAM
Since inspection or accident Last Inspection
Event Location Runway Number and Location --
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --