Accident Details
On Sunday, April 4, 1965, at 1459 MEZ, a glider pilot departed Dittingen airfield in Switzerland on a Ka-8 glider (registration HB-630) for a thermal flight near Mount Blauen. After a normal tow and climb, about 20 minutes later, the glider entered an irregular spiral descent and struck trees on the southern slope of Mount Blauen. The aircraft was left hanging in the treetops.
Damage and Injuries
The glider sustained heavy damage, estimated at 60-70% of its value. Two medium-sized beech trees had to be felled during recovery. The pilot was found dead without external injuries.
Pilot Information
The pilot, born in 1918, held a glider pilot license issued July 31, 1963, valid until January 26, 1967. His total flight experience was approximately 50 hours and 160 flights. A medical examination on January 27, 1965, had not revealed any critical findings. However, an earlier heart attack had been reported; the pilot had undergone bed rest and a several-week cure, though an electrocardiogram (ECG) had shown no signs of infarction. His treating physician had advised against flying, but the pilot did not follow that advice.
Aircraft Information
The Ka-8 is a single-seat high-wing glider of mixed construction, designed by Poppenhausen (West Germany) and manufactured by Schleicher. The aircraft had a Swiss operating permit valid until September 24, 1965. The owner was the Zwingen Gliding Group.
Post-Accident Findings
An autopsy revealed that the pilot had suffered a fresh, rapidly fatal heart attack due to coronary sclerosis, a condition that must have existed for some time. The last periodic medical check-up on January 27, 1965, had not indicated any issues. The underlying heart damage likely already existed at the time of the first medical examination in October 1962, but the pilot had not reported related disturbances. An ECG at the last check-up might have revealed the condition, but such tests are not mandatory for non-professional pilots.
Conclusion
The accident was caused by the pilot suffering a rapidly fatal heart attack during flight.