Aircraft Accident/Incident Report

Jackson, Montana 59736
Saturday, December 14, 1991 12:39 MST

NTSB Narrative Summary Released at Completion of Accident

THE PILOT WAS FLYING UP A MOUNTAIN RIDGE AT A LOW ALTITUDE ABOVE THE GROUND, SEARCHING FOR CATTLE, WHEN HE ENCOUNTERED DOWNDRAFT WINDS. HE ATTEPTED TO TURN DOWNSLOPE AT A LOW AIRSPEED AND THE AIRCRAFT STALLED. THE PILOT HAD 17 DEGREES FLAPS EXTENDED AND THE ACFT WAS NEAR GROSS WEIGHT. THE ELEVATION AT THE ACCIDENT SITE WAS 7500 FT. MSL.

NTSB Probable Cause Narrative

LOSS OF CONTROL DUE TO THE PILOT'S FAILURE TO MAINTAIN PROPER AIRSPEED. FACTORS RELATING TO THE ACCIDENT WERE THE IMPROPER FLAP SETTING, THE HIGH DENSITY ALTITUDE, MOUNTAINOUS TERRAIN, LACK OF EXPERIENCE BY THE PILOT, AND DOWNDRAFFT WINDS.

Event Information

Type of Event Accident
Event Date 12/14/1991
Event Day of the Week Saturday
Time of Event 1239
Event Time Zone Mountain Standard Time
Event City JACKSON
Event State MONTANA
Event Country --
Zipcode of the event site 59736
Event Date Year 1991
Event Date Month 12
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 0
Degrees magnetic from airport 0
Airport Elevation --
Weather Briefing Completeness Full
Investigator's weather source Weather Observation Facility
Time of the weather observation 1236 Mountain Standard Time
Direction of event from weather observation facility (degrees) 210
Weather Observation Facility ID 27U
Elevation of weather observation facility 4045
Distance of event from weather observation facility (units?) 18
Time Zone of the weather observation MST
Lighting Conditions Day
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) 25
Air Temperature at event time (in degrees celsius) -6
Dew Point at event time (in degress fahrenheit) -10
Wind Direction (degrees magnetic) 0
Variable Wind Indicator Unknown
Wind Speed (knots) 0
Wind Velocity Indicator Calm
Wind Gust Indicator Unknown
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) --
Density Altitude (feet) 6500
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury Serious
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor 1
Injury Total None --
Injury Total Serious 2
Injury Total All 3
Investigating Agency NTSB
NTSB Docket Number (internal use) 1938
NTSB Notification Source --
NTSB Notification Date --
NTSB Notification Time 0
Fiche Number and/or location -used to find docket information 45102
Date of most recent change to record Dec 12 2000 10:54AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N4244L
NTSB Number SEA92LA028
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Destroyed
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name CESSNA
Aircraft Model C-172G
Aircraft Series Identifier C-172G
Aircraft Serial Number 17254313
Certified Max Gross Weight 2300
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 100 Hour
Date of Last Inspection Oct 24 1991 12:00AM
Airframe hours since last inspection 27
Airframe Hours 4734
ELT Installed Yes
ELT Activated Yes
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name BUTTE AVIATION, INC.
Aircraft Owner Street Address 4602 HARRISON AVENUE
Aircraft Owner City BUTTE
Aircraft Owner State MT
Aircraft Owner Country
Aircraft Owner Zipcode 59702
Operator is an individual? --
Operator Name BUTTE AVIATION, INC.
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address 4602 HARRISON AVENUE
Operator City BUTTE
Operator State MT
Operator Country
Operator Zip code 59702
Operator Code BTJA
Owner has at least one certificate Yes - certificate holder
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) Aerial Observation
Second Pilot on Board No
Departure Point Same as Event No
Departure Airport Code BTM
Departure City BUTTE
Departure State MT
Departure Country
Departure Time 1133
Departure Time Zone MST
Destination Same as Local Flt --
Destination Airport Code BTM
Destination City BUTTE
Destination State MT
Destination Country
Specific Phase of Flight Climb
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 2 2001 10:35AM
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 --