What happened
On January 30, 1964, a Piper Cub J3C, registration HB-OXP, was performing operations at the Altenrhein airfield. Following a landing, the aircraft was taxiing along a grass runway that was notably bumpy and covered in hard frost. During the landing roll, a landing gear strut failed, leading to damage to the aircraft.
The investigation
Investigators examined the structural integrity of the landing gear components and the condition of the airfield surface. The inquiry focused on the mechanical state of the strut and the impact of the runway conditions during the landing phase. The investigation confirmed that there were no injuries to the two occupants on board.
Findings
Technical analysis determined that the failure of the landing gear strut was likely caused by overstressing a component that had been previously weakened by corrosion. The uneven and frozen nature of the grass runway provided the physical stress necessary to trigger the failure of the compromised part.