Accident Summary
On 14 July 1983 at approximately 1513 local time, a Standard Cirrus glider registered HB-1217 departed from Schänis airfield for a training flight under tow. About 2 km from the airfield at an altitude of approximately 200 m above ground, the towline broke. The glider entered an uncontrolled attitude. The pilot attempted to bail out but was fatally injured upon impact as his parachute had not fully deployed. The glider was destroyed.
Flight History
The pilot, a Swiss citizen born in 1937, held a glider pilot license issued by the Austrian Federal Office for Civil Aviation and a Swiss glider pilot license valid until 29 June 1984. He had logged 136:56 hours in gliders, of which 13:31 hours were on the accident model. The tow pilot, a Swiss citizen born in 1940, held a private pilot license and a glider pilot license. He had 965 total flight hours with 4387 landings.
Aircraft Information
The glider was a Standard Cirrus, serial number 429, built in 1974 by Schempp-Hirth. It was owned by Segelfluggruppe Lägern, Schänis. At the time of the accident, its weight was approximately 306 kg and center of gravity was within limits. The towplane was a Robin DR 400-180R HB-EXP, manufactured in 1975, equipped with a towline retraction system.
Weather Conditions
According to the meteorological report, the general weather was characterized by flat pressure distribution with light north foehn tendency. At the accident site, there were 2-3/8 cumulus clouds with a base of 2200-2400 m ASL, visibility 5 km, wind from NW at 5-10 kt with gusts up to 20 kt, temperature 24°C, dew point 12°C. A witness at the scene stated there was no turbulence.
Accident Sequence
The tow pilot reported that the takeoff was exemplary and the climb proceeded normally. Near the Benkenerbüchel, the tow plane encountered an updraft, showing 3 m/s climb. The glider deviated from normal attitude two to three times. Suddenly, the tow pilot felt a jerk, as if the glider had released with a taut towline. He no longer saw the glider in his rearview mirror and called on the radio but received no answer. He then initiated a descent, activated flaps and carburetor heat, reduced power, and performed a 180° right turn. At about 180 m AGL, approximately 20 seconds later, he saw the glider in a nearly vertical descent with the tail down, not much lower than the tow plane had been. About halfway to the ground, he saw something fall from the glider. The glider's attitude then somewhat normalized before it struck the ground at a shallow angle. A witness observed the glider with its nose steeply down, then it rotated over the right wing and performed a 360° spiral descent before disappearing behind trees. After the trees, the glider was seen inverted on the ground.
Wreckage Examination
The glider was found inverted on a flat meadow. The tail section had broken off. The landing gear was extended and locked. The air brakes were unlocked. The trim lever was neutral. The harness buckles were open and undamaged. The canopy frame was still attached but the plexiglass shattered; the jettison mechanism was functional and still latched. The towline had broken at the weak link, which remained attached to the glider. The release mechanism functioned normally in tests. The pilot's body was found 35 m from the wreck, lying on his back. The parachute ripcord handle protruded 15 cm from its housing and was still held by the pilot's left hand. The drogue chute was deployed, and the main parachute was partially deployed with fabric entangled in the shroud lines.
Probable Cause
The accident was attributed to a parachute jump from too low an altitude after a towline break during a tow flight.