Accident Details
On October 2, 2012, at approximately 0900 eastern daylight time, a Cessna 310I, registration N8025M, operated by a private individual, sustained substantial damage while taxiing after landing at Burlington International Airport (BTV) in Burlington, Vermont. The private pilot and a passenger were not injured. Visual meteorological conditions prevailed, and no flight plan had been filed for the local personal flight conducted under 14 Code of Federal Regulations Part 91.
Sequence of Events
According to the pilot, the airplane landed without incident on runway 15, an 8,320-foot-long asphalt and concrete surface. While taxiing toward the end of the runway and making a right turn onto taxiway "C," the left landing gear began to collapse. The left side of the airplane struck the ground, resulting in substantial damage to the left wing and left horizontal stabilizer.
Examination Findings
A subsequent examination by a Federal Aviation Administration (FAA) inspector revealed that the left main gear bellcrank pin had separated from its bushing. The pin was not located. The left main gear bellcrank and retraction link were removed and forwarded to the NTSB Materials Laboratory in Washington, D.C., for detailed examination.
Aircraft Background
The airplane was manufactured in 1964. According to an FAA inspector, at the time of the accident, the airplane had accumulated about 3,675 total operating hours and 25 hours since its most recent annual inspection, which was performed on August 8, 2012.
Metallurgical Analysis
Metallurgical examination revealed that the bellcrank and retraction link were connected by a pin inserted through a clevis on the long arm of the bellcrank and a pivot hole on the retraction link. One of the clevis tangs was bent outward and contained a small crack. Both flange bushings were fractured in similar manners on the inside of the clevis, and the liberated halves displayed features consistent with overstress. No evidence of progressive cracking was observed. The edges of the inner bore of the pivot hole in the retraction link were locally deformed radially outward in one direction on each side of the link, consistent with pin contact.
Manufacturer Input
According to a representative from Cessna Aircraft Company, the manufacturer was not aware of any previous failures or separations involving only the main landing gear bellcrank pin on Cessna 310 series airplanes.
Additional Information
Additional details can be found in the Materials Laboratory Factual Report located in the public docket.