N425GZMitsubishi MU-2B-40 · 1980

On January 29, 2020, about 0900 central standard time, a Mitsubishi MU-2B-40 airplane, N425GZ, was substantially damaged when it was involved in an accident at Flying Feathers Airport (11Y), Chilton, Wisconsin. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 personal flight.

The National Transportation Safety Board (NTSB) was informed of the accident on March 12, 2020, by the airframe manufacturer; it was not reported to the NTSB by the pilot. The pilot stated that while landing at his private turf airstrip, the airplane yawed left and the right wing was substantially damaged when it contacted the ground.

On December 14, 2019, the pilot completed an initial MU-2 training course, which included 14.9 flight hours and 20 hours of ground training as required 14 CFR Part 91 Subpart N.

An examination of the airplane, which included engine rigging, propellers, and flight control continuity, did not reveal an anomaly that would have resulted in a directional control issue.

The flight manual contained landing distance information for a dry, hard surface runway. Landing distance information for a turf runway was not available to the pilot. Investigators calculated airplane landing performance based on ambient temperature, calm wind, zero runway slope, an airplane weight of 500 lbs above empty weight, flaps at 20°, and no use of reverse thrust. Estimated landing distance over a 50 ft obstacle and ground roll were 2,500 and 1,500 ft, respectively. The airplane manufacturer estimated the landing distance over a 50 ft obstacle and ground roll for a turf (or wet) runway to be about 4,250 and 3,250 ft, respectively. The pilot did not respond to requests for additional information, such as expected landing distance, runway braking condition, touchdown location, actions taken after touchdown, and where the airplane departed the runway surface.