What happened
On 7 July 2019, a Schleicher KA6E glider, registration F-CECS, was performing a solo training flight at the Mont-Dauphin Saint-Crépin aerodrome. The aircraft was being launched via a winch takeoff on an unpaved runway.
As the winch launch commenced, the right wing of the glider dropped. The student pilot attempted to maintain alignment and level the wings using the rudder pedals and control stick, but was unable to stabilize the aircraft. In an attempt to abort the launch, the pilot pulled the cable release handle; however, the initial attempt failed to release the cable. Upon a second, more forceful pull, the cable was released. This caused the glider to pivot around the right wing, which struck the ground, before the aircraft lifted approximately one meter and then fell forward onto its nose, coming to rest at the edge of the runway. The aircraft sustained severe damage.
The investigation
The investigation analyzed video footage from a smartphone, meteorological data, and statements from the student pilot, the instructor, and the wing runner. The investigation examined the aircraft's handling characteristics, the mechanical operation of the release handle under tension, and the meteorological conditions at the time of the accident.
Findings
- The aircraft experienced a roll instability immediately following the start of the takeoff run.
- The student pilot failed to release the cable on the first attempt because insufficient force was applied to the handle to overcome the high tension of the cable.
- The instructor noted that the release handle requires significantly more effort to actuate when the cable is under maximum tension during a launch compared to when the cable is slack.
- The wing runner released the left wing immediately at the start of the run rather than following the aircraft, which contributed to the rapid wing drop.
- Meteorological conditions included a light breeze from the southeast with potential ground turbulence.