LAX01LA189

The left main landing gear axle fractured and collapsed during the landing roll, which resulted in a ground loop and substantial damage to the gearbox. The axle fractured in the vicinity of a weld. An entry in the airplane's logbook indicated that the airplane had sustained a hard landing about 15 years prior to this accident. The entry stated that maintenance technicians inspected the axle using the dye penetrate method. No logbook entry noted that the axle had been changed. The manufacturer's representative inspected the axle and reported that several items did not conform to the type design. The manufacturer's representative concluded that the axle had been cracked and rewelded, and the weld did not conform to specifications. The weld at the base plate had a larger radius than specified, which resulted in a flat surface that was insufficient to allow proper seating of the heads of the bolts that mounted the wheel to the axle. The manufacturer's representative felt the axle failed in the weld heat affected zone due to improper repair.

On May 20, 2001, about 1220 Pacific daylight time, a Bellanca 7GCBC, N86727, ground looped on landing at the Stead Airport, Reno, Nevada. Aero Ways, Inc., was operating the airplane under the provisions of 14 CFR Part 91. The private pilot, the sole occupant, was not injured; the airplane sustained substantial damage. The personal cross-country flight departed Susanville, California, about 1145. Visual meteorological conditions prevailed, and no flight plan had been filed.

The pilot stated that he departed Stead earlier that morning to drop off a passenger at Susanville. The airplane was difficult to land, but he did not try to determine the cause of the problem. On the return to Stead, the left main landing gear axle fractured and collapsed during the landing roll. The airplane ground looped resulting in substantial damage to the gearbox.

The Federal Aviation Administration (FAA) accident coordinator noted that the fracture was in the vicinity of a weld. The accident coordinator noted an entry in the airplane's logbook, which indicated that the airplane had sustained a hard landing about 15 years prior to this accident. The entry stated that maintenance technicians inspected the axle using the dye penetrate method. The accident coordinator found this unusual since the axle was steel. He did not find an entry, which noted that the axle had been changed. He assumed that the axle was original equipment and had the same total time as the airplane, which was 4,176 hours.

The accident coordinator sent the axle to the manufacturer (American Champion Aircraft Corporation) for examination. The manufacturer's representative reported that several items did not conform to the type design. The weld at the base plate did not conform to the specifications of drawing 2-1917 Rev. D, which specified a fillet weld radius of 0.0625 inches rather than the measured 0.125 inches. The drawing also noted that a flat surface of 0.56-inch diameter should have been maintained around each bolthole on the axle. The manufacturer's representative said they required this flat surface in order for the bolt head to sit flush to the mounting surface when the wheel was mounted to the axle. He said the larger radius of the weld would not allow this.

The manufacturer's representative concluded that the axle had been cracked and rewelded, and the weld did not conform to specifications. He felt the axle failed in the weld heat affected zone due to improper repair.