NTSB Factual Report

On November 23, 2011, about 1630 central standard time, an Aviat Aircraft Inc. “Husky” A-1B airplane, N252U, nosed over after landing on a sandbar near Gainesville, Texas. The commercial rated pilot, sole occupant, was not injured. The airplane was substantially damaged during the accident. The aircraft was registered to and operated by C&M Kuhn, LLC under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, which operated without a flight plan. The flight departed KT31, McKinney, Texas at 1430.

The pilot reported, during a landing on a sandbar that the airplane began a slow turn to the right. He added that it appeared that the right brake locked-up and he tried to correct the right turn by adding full left rudder, left aileron, and full aft elevator. However, the airplane nosed over and came to rest on its back. The airplane sustained substantial damage to the vertical stabilizer, wings, and wing strut.

The airplane was lifted from the sandbar by helicopter, to nearby airfield. The airplane remained on its back while the recovery crew disassembled the airplane for transport. The crew noted that the main landing gear wheels were free to rotate.

Once the airplane was at the salvage yard, a mechanic inspected the airplane. The airplane was equipped with oversized Alaskan Bush wheels, under Supplemental Type Certificate (STC) SA01015SE. The mechanic also noted that there was a circular, “witness mark” on the right tire that corresponded to the brake caliper. The mechanic stated that with low tire pressure and a side load, the tire could come in contact with the brake caliper.

NTSB Probable Cause

The right main gear tire contacting the brake caliper, which resulted in an uncommanded brake effect on the wheel.