Primary finding
Probable cause
The pilot's failure to maintain directional control during landing.
Investigator assessment
Analysis narrative
The private pilot reported that, shortly after touchdown during landing, the experimental, amateur-built tailwheel equipped airplane immediately veered to the left. The pilot corrected with right rudder and applied engine power; however, the airplane subsequently ground looped, during which the right main landing gear strut collapsed. The pilot, who was the builder of the airplane, reported that this was the second time the gear struts had bent on this airplane. Following the first event, the pilot had reinforced the landing gear strut, but he believed that the design of the main landing gear was unable to withstand the routine stresses of landing.
Source record
Factual narrative
On March 22, 2017, about 1130 mountain standard time, an experimental, amateur-built, Christopher L. Maxcy STOL King airplane, N268CR, sustained substantial damage during the landing roll at the Bozeman Yellowstone International Airport (BZN), Bozeman, MT, following a landing gear collapse. The private pilot was not injured. The airplane was registered and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no flight plan was filed for the personal, local flight which departed about 1040. The pilot reported that just after touchdown, the tail-wheeled airplane immediately veered left, and he counteracted with right rudder and a little power, but was unable to maintain direction control of the airplane. The airplane subsequently ground looped and the right main landing gear collapsed, resulting in the outboard portion of the right wing striking the runway. The airplane came to rest off the east side of the runway. Near the time of the accident, the winds were reported as variable at 3 knots. The high-wing airplane was designed for short take-off and landing (STOL) performance. It's fuselage was composed of a welded steel frame with an extended conventional landing gear. Postaccident examination of the airplane by a Federal Aviation Administration inspector revealed that the right wing was bent upwards about mid-span and was substantially damaged. Additionally, the right landing gear assembly had collapsed under the airplane. The owner and builder of the airplane stated that he had experienced a previous incident where the landing gear strut was bent during a landing, and he replaced it with a heavier duty version. He further stated that the landing gear design was not strong enough due to its long length and the angles of the gear.