Mid-air collision between Ka 6 and ASK 13 near Bad Salzdetfurth results in fatality
On June 26, 1999, a mid-air collision occurred near Bad Salzdetfurth, Germany, involving an Alexander Schleicher Ka 6 CR and an Alexander Schleicher ASK 13. Both gliders were engaged in thermaling when they lost sight of each other and collided at approximately 600 meters above ground. The Ka 6 CR entered a spiraling dive and crashed, resulting in the pilot's fatality. The ASK 13 suffered severe damage, but the student pilot successfully bailed out using a parachute. The investigation found no technical faults with the aircraft.
- Winch launch thermaling: After a winch launch, the KA6CR pilot conducted a thermaling flight north of the Steinberg-Wesseln glider site before moving toward better lift.
- Converging thermals: Seeing the ASK 13 climbing well in a thermal south of the airfield, the KA6CR pilot flew over to the same updraft area and began circling beneath it in the same left-hand direction.
- Circle path overlap: As both gliders continued left-hand circling in the same thermal, the KA6CR climbed more efficiently and adjusted its circling to try to climb above the ASK 13, causing their flight paths to converge at similar altitude.
- Loss of mutual sight: Around 600 m above ground both pilots lost visual contact with each other, with the ASK 13 student assuming the KA6CR had left the thermal.
- Wing-to-wing collision: The KA6CR approached from slightly above and left, its left wing striking the ASK 13’s right wing, severely damaging both gliders and breaking off about 2.5 m of the KA6CR’s left outer wing.
- Bailout attempts: The ASK 13 student reported the collision by radio and successfully bailed out under parachute, while the KA6CR pilot also attempted a bailout but had insufficient height to deploy the parachute.
- Crash - fatal: With its left wing partially missing, the KA6CR entered a spiraling dive and crashed into a garden near Bad Salzdetfurth, fatally injuring the pilot, while the unmanned ASK 13 crashed into a meadow.