Loss of Control on Ground: North American AT-6F Texan, N7976A; accident occurred July 24, 2019 at Wittman Regional Airport (KOSH), Oshkosh, Winnebago County, Wisconsin

Additional Participating Entity:
Federal Aviation Administration / Flight Standards District Office; Milwaukee, Wisconsin

Aviation Accident Final Report - National Transportation Safety Board: https://app.ntsb.gov/pdf

Investigation Docket - National Transportation Safety Board: https://dms.ntsb.gov/pubdms

https://registry.faa.gov/N7976A

Location: Oshkosh, WI
Accident Number: CEN19CA237
Date & Time: 07/24/2019, 1200 CDT
Registration: N7976A
Aircraft: North American AT 6F
Aircraft Damage: Substantial
Defining Event: Loss of control on ground
Injuries: 1 None
Flight Conducted Under: Part 91: General Aviation - Personal

Analysis 

The pilot reported he was returning to the airfield as part of an 11-ship formation. The wind at the airfield was from between 220° and 230° and 7 to 8 knots. He landed the tailwheel-equipped airplane on the left side of the runway and kept the tail up during landing rollout to allow for spacing with the other aircraft in the formation. When he began to lower the tail to the runway, the wind hit the airplane' left side and lifted the left wing. Despite the pilot's control inputs, the airplane crossed to the right side of the runway, continued into grass, and came to a stop facing south.

The left wingtip, aileron, and outboard aileron hinge struck the ground during the excursion, substantially damaging the airplane.

The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation.

Probable Cause and Findings

The National Transportation Safety Board determines the probable cause(s) of this accident to be:
The pilot's loss of directional control during landing with a quartering tailwind, which resulted in a runway excursion and subsequent substantial damage.

Findings

Aircraft
Directional control - Not attained/maintained (Cause)

Personnel issues
Aircraft control - Pilot (Cause)

Environmental issues
Tailwind - Effect on operation (Cause)

Factual Information

History of Flight

Landing
Other weather encounter

Landing-landing roll
Loss of control on ground (Defining event)
Attempted remediation/recovery
Runway excursion
Collision with terr/obj (non-CFIT)

Pilot Information

Certificate: Private
Age: 61
Airplane Rating(s): Multi-engine Land; Single-engine Land; Single-engine Sea
Seat Occupied: Unknown
Other Aircraft Rating(s): None
Restraint Used:
Instrument Rating(s): Airplane
Second Pilot Present:
Instructor Rating(s): None
Toxicology Performed:
Medical Certification: Class 3 With Waivers/Limitations
Last FAA Medical Exam: 05/01/2018
Occupational Pilot: No
Last Flight Review or Equivalent: 02/03/2018
Flight Time:  2842 hours (Total, all aircraft), 380 hours (Total, this make and model), 73 hours (Last 90 days, all aircraft)

Aircraft and Owner/Operator Information

Aircraft Make: North American
Registration: N7976A
Model/Series: AT 6F G
Aircraft Category: Airplane
Year of Manufacture: 1959
Amateur Built: No
Airworthiness Certificate:
Serial Number: 121-43192
Landing Gear Type: Retractable - Tailwheel
Seats:
Date/Type of Last Inspection:
Certified Max Gross Wt.: 5300 lbs
Time Since Last Inspection:
Engines: 1 Reciprocating
Airframe Total Time:
Engine Manufacturer: Pratt & Whitney
ELT:
Engine Model/Series: R1340 SERIES
Registered Owner: Witham Warbirds Llc
Rated Power: 550 hp
Operator: Witham Warbirds Llc
Operating Certificate(s) Held: None 

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation:
Distance from Accident Site:
Observation Time:
Direction from Accident Site:
Lowest Cloud Condition:
Visibility:  10 Miles
Lowest Ceiling:
Visibility (RVR):
Wind Speed/Gusts: 8 knots /
Turbulence Type Forecast/Actual: /
Wind Direction: 220°
Turbulence Severity Forecast/Actual:
Altimeter Setting:
Temperature/Dew Point:
Precipitation and Obscuration:
Departure Point: Oshkosh, WI (OSH)
Type of Flight Plan Filed:
Destination: Oshkosh, WI (OSH)
Type of Clearance: None
Departure Time:  CDT
Type of Airspace:

Airport Information

Airport: Wittman Rgnl (OSH)
Runway Surface Type: Concrete
Airport Elevation: 808 ft
Runway Surface Condition: Dry
Runway Used: 36
IFR Approach: None
Runway Length/Width: 8002 ft / 150 ft
VFR Approach/Landing: Full Stop

Wreckage and Impact Information

Crew Injuries: 1 None
Aircraft Damage: Substantial
Passenger Injuries: N/A
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 1 None

Latitude, Longitude: 43.991389, -88.560000 (est)