NTSB Factual Report

On July 16, 2005, at 1540 Pacific daylight time, a Cessna A188B, N731GE, ground looped during landing at the Eastern Sierra Regional Airport (BIH), Bishop, California. The airplane was operated by Gudgel's Aero Ag as a 14 CFR Part 91 positioning flight. The airline transport pilot, who was the sole occupant, was not injured. The airplane sustained substantial damage. Visual meteorological conditions prevailed, and a flight plan had not been filed for the cross-country flight, which originated from the Flying M Ranch, Yerington, at 1450.

According to the pilot's written statement, he made a smooth landing in the tail wheel equipped airplane, but shortly after touchdown, the airplane began to drift to the right. He applied left rudder to correct, but the airplane continued to drift to the right. He applied additional left rudder, to no avail, and a "violent tail wheel shimmy developed." The pilot reduced aft elevator control in an attempt to reduce the load on the tail wheel, but the shimmy became so violent he had trouble keeping his feet on the rudder pedals. The pilot then heard a loud bang and the aircraft made a sudden turn to the left. The shimmy stopped, but the aircraft rolled up on the right wheel with the left wheel up in the air. The pilot then applied full left aileron to keep the right wing from contacting the ground, and right rudder to stop the left turn. He later neutralized the rudder input in an attempt to keep the airplane on the runway. After the airplane turned approximately 240 degrees to the left of its original touchdown heading, the ground loop stopped.

According to the pilot, the tail wheel failed, the fuselage was bent forward of the empennage, and the right main landing gear was bent. According to the Federal Aviation Administrator (FAA) inspector who responded to the accident site, the tail wheel mount failed at its attachment area on bottom side of the empennage, which resulted in the tail wheel rotating to the left side coming to rest inverted (mount side down; tire side up). Photographs taken at the accident site revealed that the steering cables remained attached to their respective tail wheel steering horns. On April 5, 2005, the airplane underwent an annual inspection at an airframe total time of 4,644.9 hours, or about 20 hours prior to the accident.

At 1556, the BIH weather observation facility reported the weather as: wind variable at 6 knots; visibility 10 statute miles; clear sky; temperature 41 degrees Celsius; dew point 0 degrees Celsius; and altimeter setting of 29.92 inches of mercury.

The pilot reported accumulating a total of 26,612 hours of flight time, of which 3.8 were accrued in the accident airplane make and model.

NTSB Probable Cause

the failure of the tailwheel mount during the landing roll, which resulted in a ground loop.