What happened
On 11 June 2005, a Lancair 320, registration G-CBAF, was performing a private flight at Lydd Airport, Kent. The flight was conducted in good weather conditions with a light surface wind. During the landing sequence on Runway 03, the main wheels touched down first, followed shortly by the nose wheel.
Approximately one second after the nose wheel made contact with the asphalt, the nose of the aircraft tipped downward. This sudden movement caused the propeller to strike the runway, which immediately stopped the engine. The aircraft came to a halt after the nose wheel assembly detached from the aircraft.
The investigation
Investigators examined the aircraft and performed a metallurgical analysis of the components. The inspection revealed that the nose wheel had become detached from its attachment yoke. While the four bolts connecting the yoke to the nose leg remained within the assembly, three of the four nuts had been stripped from the bolts and were found scattered between the runway threshold and the aircraft.
the investigation also noted that the debris guard had been deformed, allowing it to contact the tyre. This contact prevented the wheel from rotating. Examination of the attachment bolt holes in the yoke showed deformation, suggesting the bolts had been extracted in a vertical direction as the yoke pivoted rearwards.
Findings
- The nose wheel attachment yoke had detached from the nose landing gear leg.
- Three of the four attachment bolt nuts had been stripped from the bolts due to tensile loading.
- The deformation of the bolt holes indicated that the assembly had pivoted about the rear attachment bolt line.
- It is possible that the attachment bolts had previously failed or been damaged by an impact with an object, such as a pothole or raised lip, during a prior flight.