Aircraft Accident/Incident Report

Winston, Montana 59635
Saturday, October 18, 1997 21:30 MDT

NTSB Narrative Summary Released at Completion of Accident

Post accident inspection revealed a loose bellows housing on the MA-6AA carburetor's automatic mixture control. The bellows housing was found loose on the threaded tube, which was still locked to the seat, allowing the bellows to screw down onto the tube, thereby restricting the fuel delivery orifice. The seat and lock nut remained securely bolted to the float. The last recorded carburetor repair was on 7/22/93, with 817 hours since that repair. Records did not reflect the nature of that repair. According to the carburetor manufacturer's engineering drawings, the bellows is bonded to the threaded tube with a permanent type plastic resin.

NTSB Probable Cause Narrative

Fuel starvation due to fuel flow restriction from a failed carburetor automatic mixture control device. Factors include night light conditions for the forced landing.

Event Information

Type of Event Accident
Event Date 10/18/1997
Event Day of the Week Saturday
Time of Event 2130
Event Time Zone Mountain Daylight Time
Event City WINSTON
Event State MONTANA
Event Country --
Zipcode of the event site 59635
Event Date Year 1997
Event Date Month 10
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
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 Not pertinent
Investigator's weather source Weather Observation Facility
Time of the weather observation 2156 Mountain Daylight Time
Direction of event from weather observation facility (degrees) 0
Weather Observation Facility ID HLN
Elevation of weather observation facility 3874
Distance of event from weather observation facility (units?) 0
Time Zone of the weather observation MDT
Lighting Conditions Night/Dark
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 0
Sky/Lowest/Cloud Conditions Clear
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 30
Air Temperature at event time (in degrees celsius) 4
Dew Point at event time (in degress fahrenheit) 2
Wind Direction (degrees magnetic) 310
Variable Wind Indicator Unknown
Wind Speed (knots) 7
Wind Velocity Indicator Unknown
Wind Gust Indicator Unknown
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 30
Density Altitude (feet) --
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor --
Injury Total None 2
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 1707
NTSB Notification Source --
NTSB Notification Date Oct 21 1997 12:00AM
NTSB Notification Time 1445
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Dec 8 2000 12:38PM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N47AH
NTSB Number SEA98LA006
Missing Aircraft Indicator N
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 Bell
Aircraft Model 47-G3B
Aircraft Series Identifier 47-G3B
Aircraft Serial Number 2645
Certified Max Gross Weight 2850
Aircraft Category Helicopter
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 3
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Annual
Date of Last Inspection Sep 30 1997 12:00AM
Airframe hours since last inspection 96
Airframe Hours --
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name DALE E. HORNE
Aircraft Owner Street Address POB 67 LITTLE BLACKFOOT RIVER
Aircraft Owner City ELLISTON
Aircraft Owner State MT
Aircraft Owner Country
Aircraft Owner Zipcode 59728
Operator is an individual? --
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? No
Certified for Part 133 or 137 Operation Unknown
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 8U8
Departure City TOWNSEND
Departure State MT
Departure Country
Departure Time 2117
Departure Time Zone MDT
Destination Same as Local Flt --
Destination Airport Code HLN
Destination City HELENA
Destination State MT
Destination Country
Specific Phase of Flight Cruise
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 2 2001 10:34AM
User who most recently changed record dbo
Since inspection or accident --
Event Location Runway Number and Location 0
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --