What happened
On March 15, 2017, a private flight involving a Carbon Cub EX, registration HB-YOU, was conducting glacier flights in the Glarner Alps. After completing nine landings at the Vorabgletscher/GR airfield, the pilot proceeded toward the Limmerenfirn/GL airfield.
While the initial landing and subsequent takeoff at Limmerenfirn were successful, difficulties arose during the second takeoff attempt. As the aircraft accelerated downslope, it began a continuous leftward deviation. The pilot aborted the takeoff at approximately 20 knots. As the aircraft slowed, it tipped sideways toward the downslope side, resting on the right wingtip. This movement caused the right main landing gear strut to break, resulting in the gear and ski collapsing inward under the fuselage. The incident resulted in one person slightly injured.
The investigation
The investigation focused on the mechanical failure of the landing gear and the environmental conditions at the time of the accident. Investigators examined the aircraft's movement during the aborted takeoff and the impact of the terrain slope. The investigation established that the aircraft sustained damage to the right wing, the landing gear, and the lower fuselage area.
Findings
- The primary cause of the landing gear failure was the structural breakage of the right main landing gear strut during the aircraft's sideways tilt.
- The deviation during takeoff was influenced by unpredictable snow conditions combined with a light tailwind.
- The pilot noted that an earlier decision to abort the takeoff would have been beneficial to prevent the subsequent tip-over.