What happened
On August 6, 2013, a Schempp-Hirth Janus C glider, registration F-CHND, was conducting a discovery flight near Bagnères-de-Luchon, France. While returning from a 30-minute flight, the pilot entered the altitude loss zone (ZPA) to prepare for an approach to runway 01. During the downwind leg, the pilot noticed an abnormally high rate of descent. Despite attempting to retract the flaps to maintain airspeed, the descent rate remained high.
Realizing the aircraft was too low to reach the airfield under safe conditions, the pilot decided to perform a forced landing in the nearby Bagnères-de-Luchon golf course. During the final approach, the left wing struck trees, and the aircraft struck the ground heavily before coming to rest against a tree. The impact caused significant damage, including a fractured fuselage and a broken left wing.
The investigation
The investigation focused on the cause of the rapid loss of altitude and the circumstances leading to the forced landing. Investigators analyzed data from the aircraft's FLARM proximity warning system, which established the flight trajectory. The data showed the glider exited the altitude loss zone at 480 ft with a descent rate of approximately 900 ft/min, which increased to 750 ft/min in the final seconds of flight.
Physical examination of the wreckage revealed that the airbrake control was found in the unlocked position. Investigators also noted that the pilot had previously flown an Alliance 34 glider that day, which features a different cockpit ergonomics; specifically, the relative positions of the airbrake and flap controls are reversed compared to the Schempp-Hirth Janus C.
Findings
- The pilot experienced an unmanageable increase in the rate of descent during the downwind leg.
- The airbrake deployment is the primary factor contributing to the loss of altitude.
- The pilot's recent experience in an aircraft with different control ergonomics likely led to the accidental activation of the airbrakes.
- The decision to perform a forced landing was necessitated by the inability to maintain sufficient altitude to reach the runway.