Incident Overview
A pilot operating a tundra tire tailwheel-equipped airplane experienced a ground loop while back taxiing on the runway for departure. The pilot reported that earlier that day he had successfully performed one takeoff from the same airport. Before the second departure, he checked the weather and noticed that the wind had increased slightly. Despite other aircraft using the runway, he felt confident in his ability to handle the wind conditions.
Sequence of Events
During back taxiing, the pilot observed that he was applying heavy braking. A gust of wind then pushed the airplane to the left. The pilot stated that the brakes had become too hot to maintain directional control, resulting in a ground loop. The airplane sustained substantial damage to the left and right wings, ailerons, horizontal stabilizer, and elevator.
Pilot Comments
The pilot noted that there were no preaccident mechanical anomalies with the airplane that would have precluded normal operation. In the recommendation section of the NTSB Accident/Incident Reporting Form 6120.1, he specifically identified the large 29-inch tundra tires as a contributing factor, stating that they caused the brakes to heat up much faster than the smaller 850 tires he was accustomed to using.
Recommendations
Based on his experience, the pilot recommended limiting downwind taxiing to short distances, and suggested not taxiing in winds exceeding 12 knots while operating with large tundra tires. This advice reflects the operational challenges associated with increased brake heat buildup when using oversized tires on tailwheel aircraft.