The pilot reported that he was conducting a high-speed taxi test of a Buhl LA 1 at an airport in Cottage Grove, Oregon, during which he did not intend to fly, when the plane encountered a wind gust and then unexpectedly became airborne.
Insufficient runway was available to abort the takeoff, so he decided to continue flight in the traffic pattern and return to land.
On the downwind leg, the engine lost power. The pilot continued straight ahead toward an open area, and the right wing hit a tree during the forced landing.
A post-accident examination of the engine revealed no anomalies that would have precluded normal operation.
The weather conditions at the time of the accident were conducive to the formation of carburetor icing at glide and cruise power and serious icing at glide power. The airplane was not equipped with carburetor heat, and it is likely that the loss of engine power was due to carburetor icing.
Probable cause: A loss of engine power on downwind for landing due to carburetor icing, which resulted in a forced landing.
NTSB Identification: WPR15LA156
This May 2015 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.