1968 Ka 8B glider crash at Flugfeld Olten (HB-668)

Overview and aircraft details On 27 April 1968, a glider accident occurred at Flugfeld Olten. The aircraft involved was a Ka 8B glider with the registration HB-668. The glider was a shoulder-wing design with a wingspan of 15 m. It was properly certified and in airworthy condition. The owner and operator was the Segelfluggruppe Luzern. ## Pilot and flight conditions The pilot, born in 1945, held a valid glider pilot licence. His total flight training was about 40 hours. On the day of the accident, after a break of about a year and a half, he resumed training at Olten. He first completed two check flights in dual control with a glider instructor and was then authorised to fly the Ka 8B. The weather was sunny under a flat high-pressure system over Central Europe, with moderate winds from the southwest. ## Site and sequence of events Flugfeld Olten is located at 415 m above sea level and has a grass runway 05-23 measuring 560 x 30 m. For landing direction 23, the landing T is placed 100 m from the runway threshold. About 110–120 m before the threshold lies an extensive quarry roughly 10 m deep, with a cement factory on its southern side of the approach axis. The pilot took off at 1538 by aerotow and released at about 500 m above the field in the area between Olten and Aarburg. He slowly gained altitude and, while climbing to 1100 m above the field, was displaced toward the Aarau area. From there he began the return flight to Olten and noted considerable headwind. After reaching the area north of the runway threshold, with an altimeter reading of 210 m, he turned 180° to the right, intending to make a field approach from the opposite direction using two 90° turns. However, due to the prevailing southwest wind—tailwind on the opposite leg and headwind on the final approach—his final approach became too low, and he could no longer reach the airfield. In an attempt to land at least on the upper edge of the quarry, located about 100–120 m before the runway threshold in the approach sector, the wing struck the ground in a left turn, leading to a crash landing on the quarry slope. ## Damage and outcome The pilot was uninjured. The glider was heavily damaged.