Aviation Accident Final Report - National Transportation Safety Board
The National Transportation Safety Board did not travel to the scene of this accident.
Additional Participating Entity:
Federal Aviation Administration / Flight Standards District Office; Helena, Montana
Investigation Docket - National Transportation Safety Board:
Location: Bozeman, Montana
Accident Number: WPR21LA289
Date and Time: July 25, 2021, 13:44 Local
Registration: N8844K
Aircraft: Stinson 108-1
Aircraft Damage: Substantial
Defining Event: Loss of control on ground
Injuries: 2 Minor
Flight Conducted Under: Part 91: General aviation - Personal
Analysis
The pilot in the tailwheel-equipped airplane reported that, he made a normal wheel landing and as he was about to lower the tailwheel, the airplane veered to the right. He attempted to correct with left rudder control, but the airplane ground looped. The pilot opined that the airplane may have been caught by a wind gust, which started an oscillation that he was not able to correct for. The airplane sustained substantial damage to the left wing and lift strut. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operations.
Probable Cause and Findings
The National Transportation Safety Board determines the probable cause(s) of this accident to be:
The pilot’s failure to maintain directional control during landing which resulted in a ground loop.
Findings
Aircraft Directional control - Not attained/maintained
Personnel issues Aircraft control - Pilot
Factual Information
History of Flight
Landing-landing roll Loss of control on ground (Defining event)
Landing-landing roll Runway excursion
Pilot Information
Certificate: Private
Age: 36, Male
Airplane Rating(s): Single-engine land
Seat Occupied: Left
Other Aircraft Rating(s): None
Restraint Used: 4-point
Instrument Rating(s): None
Second Pilot Present: No
Instructor Rating(s): None
Toxicology Performed:
Medical Certification: Class 3 Without waivers/limitations
Last FAA Medical Exam: September 5, 2019
Occupational Pilot: No
Last Flight Review or Equivalent: September 1, 2020
Flight Time: 109 hours (Total, all aircraft), 66 hours (Total, this make and model), 70 hours (Pilot In Command, all aircraft), 25 hours (Last 90 days, all aircraft), 11 hours (Last 30 days, all aircraft), 7 hours (Last 24 hours, all aircraft)
Passenger Information
Certificate:
Age: Male
Airplane Rating(s): Seat
Occupied: Right
Other Aircraft Rating(s):
Restraint Used:
Instrument Rating(s):
Second Pilot Present: No
Instructor Rating(s):
Toxicology Performed:
Medical Certification:
Last FAA Medical Exam:
Occupational Pilot: No
Last Flight Review or Equivalent:
Flight Time:
Aircraft and Owner/Operator Information
Aircraft Make: Stinson
Registration: N8844K
Model/Series: 108-1
Aircraft Category: Airplane
Year of Manufacture: 1947
Amateur Built:
Airworthiness Certificate: Normal; Utility
Serial Number: 108-1844
Landing Gear Type: Tailwheel
Seats: 4
Date/Type of Last Inspection: Annual
Certified Max Gross Wt.: 2230 lbs
Time Since Last Inspection:
Engines: 1 Reciprocating
Airframe Total Time:
Engine Manufacturer: Franklin
ELT: Installed, not activated
Engine Model/Series: 6A4-150-B3
Registered Owner:
Rated Power: 150 Horsepower
Operator: On file
Operating Certificate(s) Held: None
Meteorological Information and Flight Plan
Conditions at Accident Site: Visual (VMC)
Condition of Light: Day
Observation Facility, Elevation: KBZN,4449 ft msl
Distance from Accident Site: 1 Nautical Miles
Observation Time: 12:56 Local
Direction from Accident Site: 325°
Lowest Cloud Condition: Clear
Visibility: 10 miles
Lowest Ceiling: None
Visibility (RVR):
Wind Speed/Gusts: 3 knots /
Turbulence Type Forecast/Actual: /
Wind Direction: 340°
Turbulence Severity Forecast/Actual: /
Altimeter Setting: 30.1 inches Hg
Temperature/Dew Point: 29°C / 3°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: Shoshone, ID (S83)
Type of Flight Plan Filed: None
Destination: Bozeman, MT
Type of Clearance: None
Departure Time: 10:00 Local
Type of Airspace: Class D
Airport Information
Airport: BOZEMAN YELLOWSTONE INTL BZN
Runway Surface Type: Asphalt
Airport Elevation: 4473 ft msl
Runway Surface Condition: Dry
Runway Used: 12/30
IFR Approach: None
Runway Length/Width: 8994 ft / 150 ft
VFR Approach/Landing: Straight-in
Wreckage and Impact Information
Crew Injuries: 1 Minor
Aircraft Damage: Substantial
Passenger Injuries: 1 Minor
Aircraft Fire: None
Ground Injuries:
Aircraft Explosion: None
Total Injuries: 2 Minor
Latitude, Longitude: 45.777236,-111.15026
