Primary finding
Probable cause
The pilot's loss of directional control after landing for reasons that could not be determined because an examination of the airplane did not reveal any anomalies that would have precluded normal operation.
Investigator assessment
Analysis narrative
The commercial pilot and two passengers had completed a local flight. After a routine touchdown and landing roll, the pilot applied the brakes to initiate a right turn onto a taxiway. The pilot reported that the right brake "grabbed immediately," causing the airplane to ground loop. A postaccident examination and disassembly of the brake system revealed no mechanical anomalies that would have precluded normal operation. The reason for the reported brake malfunction could not be determined.
Source record
Factual narrative
On July 4, 2017, about 1900 eastern daylight time, a Waco YMF airplane, N17XK, experienced a gear collapse after landing at the Butler County Regional Airport-Hogan Field, Hamilton, Ohio. The pilot and two passengers were not injured, and the airplane was substantially damage. The airplane was registered to and operated by Adventure Airtours, LLC, under the provisions of 14 Code of Federal Regulations Part 91 as a local sightseeing flight. Visual meteorological conditions prevailed at the time. The pilot reported that he just completed a local flight and was landing on runway 11. After a routine touchdown and roll out, he applied the brakes to initiate a right turn onto a taxiway. The pilot added that the right brake "grabbed immediately", causing the airplane to turn clockwise to the left. The pilot also added that the tailwheel was down and in the locked position. The left wing struck the ground and the left landing gear collapsed; the airplane came to a stop on the runway. An inspection of the airplane by the responding Federal Aviation Administration inspector noted damage to the left main landing gear and substantial damage to the left wing spar. The airplane was recovered and transported to the manufacturer's facility for repair. During disassembly of the landing gear and braking system, the manufacturer did not find any evidence of a failure in the braking system.