Flight Details
On 27 August 1972, an instructor pilot and a student pilot departed from Porrentruy airfield in the Rhönlerche II glider, registration HB-674. The purpose of the flight was to demonstrate a simulated cable break during a winch launch.
Accident Sequence
At a height of 60 to 80 meters, the instructor released the cable. The student reacted normally by establishing a descent, extending the spoilers, and announcing his intention to land straight ahead. The instructor stated that this maneuver was correct but noted that at that altitude a circuit back to the starting point was also possible.
Without noticing that the spoilers were extended, the instructor took over the controls, pushed the stick forward to accelerate, and initiated a right turn. The speed did not increase, and the rate of descent was high. Preoccupied by obstacles, the instructor did not identify the cause of the rapid descent.
Attempting a forced return to the runway, the instructor tightened the turn. Close to the ground, he saw a wooden shed and a glider trailer in his path. To avoid them, he increased the bank angle further. The right wing struck the ground, the glider pivoted right, and the tail hit the trailer. The glider came to rest 22 meters away after a half-turn, at 1231 hours local time.
Injuries and Damage
The instructor and the student sustained serious injuries. The glider was severely damaged, and minor ground damage occurred.
Pilot Information
The instructor, born in 1932, held valid glider pilot and flight instructor licenses. His total aeronautical experience was 521 hours, including 56 hours on the type. In the previous three months, he had flown 45 hours, 19 of which on the Rhönlerche. The student, born in 1951, held a valid student pilot card. His flight experience was 11.48 hours, including 4.19 hours in the previous three months, all on the accident type. The investigation found no evidence of health issues, prior accidents, incidents, or regulatory violations.
Findings
The glider was airworthy and properly certified. No technical deficiency was identified. Weather conditions were good and not a factor. During previous training flights on July 27, the instructor had practiced simulated cable breaks and returned to the starting point to avoid moving the glider to the launch position.
Cause
The investigation determined that the accident resulted from a lack of attention by the instructor during the simulated cable break.