LAX98LA074

The pilot reported that he landed on runway 30 and suddenly felt a 'bump.' The pilot further reported that at that time the aircraft began an uncommanded yaw to the left and he noted that the right main landing gear had separated from the aircraft. The aircraft came to rest on its side. An immediate inspection of the accident site yielded no sign of debris or potholes on the runway surface. An on-site examination of the aircraft found that the bolt which attached the landing gear spring to the fuselage had been bent, fractured, and distorted at an approximate 45-degree angle, and the support assembly had also been fractured. The bolt and a portion of the separated support assembly from the right main landing gear were sent to the Safety Board Materials Laboratory for testing. Details of the examination showed that the fracture surface on the bolt revealed no evidence of progressive cracking or preexisting defects. All fracture features and deformation on the bolt pieces were consistent with an overstress under bending/tension loading conditions. Examination of the bracket for the support assembly was conducted with the aid of a binocular microscope and disclosed the fracture features typical of a direct shear overstress separation.

On January 16, 1998, at 1525 hours Pacific standard time, a Cessna 195, N4498C, ground looped on landing at the Long Beach, California, airport. The aircraft sustained substantial damage and the pilot/owner, the sole occupant, was not injured. Visual meteorological conditions prevailed at the time of the accident and an IFR flight plan was on file. The personal flight originated from the Porterville, California, airport at 1420 and was terminating at the time of the accident.

A Federal Aviation Administration (FAA) inspector from the Long Beach Flight Standards District Office conducted an on-site investigation of the aircraft and spoke to the pilot. The pilot reported that he landed on runway 30, remained on the centerline, and suddenly felt a "bump." The pilot further reported that at that time the aircraft began an uncommanded yaw to the left and he noted that the right main landing gear had separated from the aircraft. The aircraft came to rest on its side. The FAA inspector also found that the bolt which attached the landing gear spring to the fuselage had been bent, fractured, and distorted at an approximate 45-degree angle, and the support assembly had also been fractured.

In a telephone interview with the Safety Board, the superintendent of airport operations at the Long Beach airport reported that he responded to the accident site immediately. He stated that he checked all points on the runways for debris or potholes or nicks in the runway surface; the only debris found was that left by the accident aircraft.

The bolt and a portion of the separated support assembly from the right main landing gear were sent to the Safety Board Materials Laboratory for testing. The report of the examination showed that the fracture surface on the bolt revealed no evidence of progressive cracking or preexisting defects. All fracture features and deformation on the bolt pieces were consistent with an overstress under bending/tension loading conditions. Examination of the bracket for the support assembly was conducted with the aid of a binocular microscope and disclosed the fracture features typical of a direct shear overstress separation.