What happened
On November 19, 2012, a Beechcraft 58, registration PT-WFO, was performing a public aviation mission from Dourados to Campo Grande, Brazil. The aircraft was carrying two pilots and four passengers.
Upon landing at Campo Grande Airport (SBCG), the crew experienced significant vibrations during the landing roll. Following the touchdown, the nose gear inadvertently retracted, causing the aircraft's nose and propellers to strike the runway surface. The impact resulted in substantial damage to the aircraft, though all six occupants escaped the incident without injury.
The investigation
CENIPA investigators examined the nose landing gear assembly and the tire to determine the sequence of failure. Laboratory analysis conducted by the Department of Aerospace Science and Technology (DCTA) revealed plastic deformation and fractures in the nose gear retract rod assembly, with fracture angles of approximately 45 degrees, indicating that the component had been subjected to extreme overload.
Technical inspections of the tire showed a rupture consistent with a burst rather than a puncture. The investigation also reviewed the aircraft's maintenance logs, noting that the annual inspection had been completed approximately 25 flight hours prior to the accident. While the maintenance records for the nose gear retract rod assembly were available from 2004, the investigators could not verify the component's overhaul history prior to that date. No foreign object debris (FOD) was found on the runway, and no specific cause for the initial tire burst could be identified.
Findings
- The primary cause of the gear failure was a tire burst on the nose landing gear.
- The burst tire created excessive friction and resistance against the ground, generating forces that exceeded the structural strength of the nose gear retract rod assembly.
- The resulting failure of the rod assembly allowed the nose gear to retract unexpectedly during the landing roll.
- The pilots were properly qualified, and the aircraft was within weight and balance limits with valid airworthiness certification.