What happened
On July 8, 2007, a Schleicher ASW-19 B glider, registration PH-998, performed an outlanding in a field near Tollebeek after the pilot was unable to reach the home airfield due to a lack of thermals. While attempting to land in a field approximately 270 meters long, the pilot encountered wooden marker posts on the right side of the landing area and adjusted the course to the left.
As the aircraft approached the ground, the pilot realized that the remaining field length was insufficient to stop the aircraft safely. Because the ground consisted of hard clay, the wheel brake provided minimal deceleration. In an attempt to stop the aircraft before the end of the field, the pilot executed a ground loop by pressing the right wing into the ground. This maneuver caused the aircraft to veer right, crossing a farm road and coming to a halt over a narrow ditch. The tail section of the aircraft struck the opposite side of the ditch, resulting in the tail boom breaking approximately two-thirds of the way behind the wings. The pilot escaped the severe impact without injury.
The investigation
The investigation focused on the pilot's approach and the environmental conditions at the time of the landing. It was established that the pilot had estimated the wind direction using nearby wind turbines rather than direct measurement. The investigation examined the aircraft's flight path, the surface conditions of the landing field, and the pilot's decision-making process during the final approach.
Findings
- The primary cause of the accident was the pilot's incorrect estimation of the wind direction, which resulted in a landing with a tailwind.
- Inadequate flight preparation meant the pilot was unaware of the actual wind direction prior to the landing.
- The pilot failed to recognize the necessity of an earlier touchdown until the aircraft was already too low to perform a slip maneuver to increase the descent rate.
- The hard clay surface of the field provided significantly less rolling resistance than softer soil, contributing to the extended landing roll.