Accident Details
Probable Cause and Findings
The failure of the left main landing gear wheel on landing due to overstress, which resulted in the pilot’s loss of directional control. Contributing to the accident was the pilot's improper decision to install wheels with insufficient loading capacity for the airplane.
Aircraft Information
Registered Owner (Current)
Analysis
On September 7, 2013, at 0900 central daylight time, N1732, an experimental-homebuilt Barrow Rose Parrakeet A-4C airplane, sustained substantial damage when the left main landing gear wheel fractured during landing rollout at Castroville Municipal Airport (CVB), Castroville, Texas. The airplane transport pilot/owner/builder was not injured. Visual meteorological conditions prevailed and no flight plan was filed for the local, personal flight conducted under 14 Code of Federal Regulations Part 91.
The pilot stated that he he made a normal, 3-point landing on runway 15. During landing rollout, the airplane began to vibrate and the left wing fell down toward the asphalt runway. The airplane then veered sharply to the right and departed the runway onto level grass and flipped over. In addition to the fractured left main landing gear wheel, the pilot reported that the rudder and the upper right wing spars were substantially damaged. The left main landing gear and propeller were also damaged.
According to the pilot, the Azusa 8-inch wheel had accrued only 11.4 hours since it was installed, and had approximately 15 cycles (landings) at the time of the accident. At the request of the National Transportation Safety Board Investigator-in-Charge (NTSB IIC), the pilot sent the fractured wheel to the NTSB's Materials Laboratory for examination. Examination of the fractured sections of the wheel revealed they were matte gray and rough consistent with overstress fracture of cast aluminum alloy. No evidence of preexisting cracks was observed.
According to the Azusa Engineering website, they manufacture wheels for small recreational and industrial vehicles including go-karts, mini-bikes, and ultra-light aircraft (aircraft with an empty weight of less than 254 pounds per Federal Aviation Regulation Part 103). N1732 weighed about 954 pounds at the time of the accident and would have required wheels with a higher loading capability than an ultra light aircraft.
When asked how this accident could have been prevented, the pilot stated, "I should have used a different wheel manufacturer!"
Data Source
Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# CEN13LA534