Incident Overview
On the morning of Saturday, 26 April 1975, routine flight operations were underway at Schänis airfield. The paved runway was used for takeoffs, while the parallel grass strip was used for landings. A glider student was assisting with the preparation of towlines for aircraft. After untangling two tow ropes, he made one ready for the next tow. To clear the other rope from the paved runway, he dragged it onto the grass strip. He failed to verify that no aircraft was approaching the runway.
Meanwhile, a glider pilot, returning from a short training flight in a Ka 8 (registration HB-679), was on final approach to grass runway 35. She had noticed the student but assumed he would remain clear of the danger area. She therefore concentrated on the landing. Fellow workers tried to warn the student by shouting, but he could not hear them due to the noise of the tow aircraft's engine.
At approximately 0938 MEZ, the student was struck on the head by the left wingtip of the just-landed HB-679. The pilot felt the impact, which yawed the glider slightly left; she immediately corrected the direction.
Damage and Injuries
The student helper sustained serious injuries. The glider suffered minor damage, with a dent on the left wing leading edge about 40 cm from the tip.
Personnel Information
The pilot, born in 1951, held a valid glider pilot license. Her total flying experience was 44 hours 13 minutes, of which 12 hours 13 minutes were on the accident type. She had flown 56 minutes in the previous 90 days, all on the accident type. She had only 8 hours 44 minutes of flight time since obtaining her license. No evidence of medical impairment was found.
The student, born in 1948, held a valid glider student license and was familiar with the airfield. He experienced retrograde amnesia from the accident.
Aircraft Information
The glider was airworthy and had no pre-existing technical defects.
Weather Conditions
At the time of the accident, weather was: clouds 1/8 Cu with base around 1500 m above mean sea level, visibility about 20 km, wind from northeast to east at 5-10 kt, temperature 10°C, no hazards. Sun azimuth 120°, elevation 042°.
Regulations
Pertinent regulations (Swiss Air Traffic Rules, Article 34, paragraph 1b) require any person moving an aircraft on or near an aerodrome to observe other traffic to avoid collisions. This citation does not imply a legal judgment.
Probable Cause
The accident resulted from: (1) the student entering the landing strip without ensuring that the approach was clear, and (2) the pilot concentrating excessively on the landing and paying insufficient attention to airfield traffic.