What happened
During the takeoff ground run, an aircraft was being towed by a glider when the tow assembly swerved off the runway. The vehicle entered a muddy grass area adjacent to the paved surface. To prevent the aircraft from becoming stuck in the mud, the pilot initiated a premature takeoff attempt before achieving adequate forward speed.
The pilot reported that the combination of insufficient airspeed and the angle of the tow rope caused the aircraft to slam back into the ground. The impact occurred during this aborted or failed lift-off phase while still connected to the towing glider.
The investigation
Examination of the event focused on the sequence of events leading to the ground contact. The primary mechanical factor identified was the physical interaction between the tow rope tension, the aircraft's pitch attitude, and the lack of aerodynamic lift due to low speed.
Findings
The accident was caused by the pilot's decision to attempt a takeoff while the aircraft was partially embedded in mud and lacking sufficient airspeed. The angle of the tow rope contributed to the downward force that resulted in the hard landing.