Incident Overview
On April 17, 1967, at approximately 18:02 Central European Time, a Piper PA-18 Super-Cub with registration HB-ORW departed from Flugplatz Hausen a.A. for a glider tow operation. The aircraft was piloted by a single individual who had completed several prior tows that day. Shortly after takeoff, at an altitude of 50 to 70 meters above ground level, the engine ceased running. The pilot attempted to restart the engine by manipulating the throttle but failed to regain power.
Accident Sequence
As the aircraft lost speed in the climb configuration, it entered a steep flight path. The pilot initiated a right turn for an emergency landing in a nearby meadow. During this maneuver, the pilot noticed high-voltage power lines crossing the approach path. Due to the urgency of the situation, the pilot did not release the tow rope immediately. The glider remained attached, pulling the tail of the Super-Cub upward and further destabilizing the aircraft. The speed dropped significantly, resulting in a near-uncontrolled state. Just before impact, the pilot shut off the ignition and mixture control. At approximately 18:03, the aircraft struck the ground in a steep attitude about one kilometer west of the runway threshold.
Damage and Injuries
The pilot sustained serious injuries but was able to exit the heavily damaged aircraft unassisted. The Super-Cub suffered severe structural damage, estimated at 80% of its value. The towed glider, a Rhönlerche (HB-697), released from the tow line and landed safely at Hausen a.A.
Investigation Findings
The Swiss Federal Accident Investigation Commission concluded that the accident was highly likely caused by a lack of fuel supply to the engine. Post-accident examination revealed the left wing tank was nearly empty, while the right tank contained approximately 45 liters of fuel. The fuel selector valve was found in the "Right Tank" position initially, but an early responder may have altered it. The investigation determined that the loss of fuel flow led to engine failure, which caused a loss of airspeed and control during the climb phase.