What happened
On June 6, 2007, an RSchneider LS-7-WL glider, registration PH-915, performed an unplanned landing in a grassy field near Vierhouten following an overland flight. The flight had departed from Malden airfield via winch launch earlier that afternoon. After approximately three and a half hours of flight, the pilot encountered a lack of thermal lift, necessitating an out-of-field landing.
Upon approaching the field, the pilot attempted to land before reaching a wooden fence at the edge of the area. Despite deploying the airbrake flaps fully, the aircraft did not descend at the expected rate, and the pilot noted that the aircraft failed to lose sufficient airspeed during the final approach. To prevent colliding with the fence, the pilot executed a ground loop maneuver. During this turn, the tail section of the aircraft broke off, resulting in heavy damage to the airframe. There were no injuries to the pilot.
The investigation
The investigation relied on information provided by the pilot, as no investigators from the Safety Board were present at the scene. The pilot suggested that the aircraft's inability to descend effectively was due to the aircraft remaining in ground effect for too long. This phenomenon was potentially exacerbated by a sudden loss of wind speed below the tree line, possibly caused by a thermal tailwind or a collapsing thermal bubble from a nearby field.
Findings
- The pilot attempted a ground loop to stop the aircraft before hitting a wooden fence.
- The aircraft's tail section separated due to the stresses of the ground maneuver.
- The pilot reported that the aircraft did not lose speed quickly enough during the landing phase, potentially due to aerodynamic ground effect or shifting wind conditions.