Accident Details
On June 29, 2013, at approximately 0645 central daylight time, a Schweizer Aircraft Corp. G-164B (registration N3633S) experienced a landing gear collapse while landing at McKellar-Sipes Regional Airport (MKL) in Jackson, Tennessee. The commercial pilot was not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the local aerial application flight conducted under 14 CFR Part 137.
After completing the aerial application, the pilot returned to the departure airport and performed a full-stall landing on runway 2. Shortly after touchdown, the airplane began drifting right. The pilot applied left aileron, rudder, and brake. As the airplane returned to the centerline, the pilot attempted to realign its direction of travel. Control inputs proved ineffective, and the pilot then applied full reverse thrust and brakes. The left brake caused the airplane to turn further left, while the right brake was unresponsive.
The airplane continued drifting left until the right main landing gear leg collapsed. Post-accident inspection revealed that the right main landing gear wheel had separated from its axle at the hub. Fractured pieces of the wheel were later recovered from the runway.
Maintenance History
According to FAA airworthiness records, the airplane was manufactured in March 1986. On January 6, 2012, the registered owner requested a replacement airworthiness certificate, noting that aircraft logs had been "burned in a hangar fire." Airframe logs covering May to December 2012 were examined. An annual inspection completed on May 20, 2012, stated, "Wheels and brakes checked-OK." Another annual inspection on December 12, 2012, documented lubrication of landing gear wheel bearings and replacement of brake pads. No subsequent maintenance entries addressed landing gear.
Examination of Components
The wheel rim and bearing hub assembly were sent to the NTSB Materials Laboratory. The rim was of split design with bearing bores in each half and a cylindrical spacer sleeve. The center sections of both rim halves had fractured into multiple pieces and separated from the periphery. Some portions of the outboard rim half's periphery also fractured. Not all rim fragments were recovered. Fracture surfaces showed only overstress fractures with no preexisting damage; some surfaces were smeared from contact forces. Bolts, nuts, and washers securing the rim halves showed no unusual characteristics.
Operational Context
The airplane owner reported a verbal contract with the operator in June 2013: the owner would provide the aircraft, pilot, and insurance; the operator would supply fuel, agricultural work, and a Part 137 certificate, and direct aircraft use. The operator agreed but stated the airplane would operate under the owner's Part 137 certificate. FAA records showed the owner did not hold a Part 137 operating certificate, and the accident aircraft was not listed on the operator's Part 137 operating specifications.