ASK 23 crash during takeoff at Schänis airfield results in severe damage
On August 23, 1987, an Alexander Schleicher ASK 23 experienced a crash during takeoff at Schänis Airfield in Switzerland. The pilot, on a familiarization flight, struggled to maintain control during the aerotow launch. The glider bounced on the runway multiple times, resulting in the fuselage breaking apart. Despite the severe damage to the aircraft, there were no fatalities or serious injuries. The official report identified loss of control during takeoff as the cause of the accident.
- Aerotow takeoff roll: During an aerotow departure on runway 34 at Schänis, the ASK 23B remained on the ground until about halfway down the runway despite accelerating normally.
- Abrupt rotation: Around mid-runway, the student pilot pulled the control stick more briskly, causing the glider to lift off abruptly and climb above the normal tow position behind the Robin DR 400.
- Overcorrection nose-down: To correct the excessive pitch-up and overstepping of the tug, the pilot pushed the stick forward, driving the glider into a hard impact with the runway and a subsequent bounce.
- Uncontrolled pitch oscillation: The pilot then repeatedly applied late and excessive pitch corrections, leading to two further, progressively harder bounces with the glider alternately overstepping the towplane and striking the runway.
- Fuselage breaks in bounce: On the third very hard impact, the fuselage tube broke in two, leaving the glider largely uncontrollable as it climbed again to about 5–10 meters and rolled off to the right.
- Crash - no injury: The glider struck the ground to the right of the runway on its right wingtip and nose and came to rest inverted, destroying the aircraft but without causing fatal or serious injury to the pilot.