WPR22FA148 · Taylorcraft BL-65

The airline transport pilot had just purchased the tailwheel-equipped, 65-horsepower airplane and was flying it from Wyoming to his home in Texas accompanied by a flight instructor. During one of their fuel stops on the first day of the trip, the instructor spoke with a local pilot and stated that the accident airplane had difficulty climbing above 8,000 ft during previous legs of the trip. The accident occurred on the second leg of the second day of the trip. The accident flight originated from an airport at an elevation about 5,500 ft mean sea level (msl), with a density altitude over 7,000 ft, and proceeded over an area of high desert terrain. About 50 nautical miles from the departure airport, the airplane was seen maneuvering at low altitude toward a ridgeline, then away from the ridgeline and toward a nearby dirt road before it descended, impacted terrain, and nosed over. The witness further reported that, at the time of the accident, the winds were gusting from the southwest, over the ridgeline, and that the airplane’s engine was running. The pilot was fatally injured. The instructor sustained serious injuries and stated that he had no recollection of the accident flight after departure. A postaccident examination of the airframe and engine did not reveal any mechanical failures that would have precluded normal operation. The accident site was located at an elevation of about 7,100 ft msl. The calculated density altitude at the accident site exceeded 9,000 ft. The operating manual for the engine make and model revealed that, at an altitude of 7,000 ft, the full throttle sea-level horsepower value is reduced to 78.9%. At 9,500 and 10,000 ft, the sea level horsepower is reduced further to 72.5% and 70.8%, respectively. Given the instructor’s statement the previous day regarding the airplane’s performance above 8,000 ft, and the estimated density altitude conditions at the accident site, it is likely that the airplane’s performance was significantly degraded during the accident flight as a result of high-density altitude. It is possible that the pilots may have also been experiencing mechanical turbulence due to the mountainous terrain and gusting wind conditions described by the witness.

Verbatim NTSB analysis and probable cause from the NTSB dataset