Fatal glider spin in Swiss Alps caused by low airspeed and pilot unwellness

Casualties unknown • Ritzingeralp, VS, CH

A glider pilot lost control of his aircraft after entering a downdraft zone, resulting in a fatal spin and the destruction of the aircraft.

What happened

On August 2, 1972, a pilot departed from Münster airfield in a Ka 8B glider, registration HB-810, for an alpine soaring flight. The flight lasted approximately three hours and ten minutes. Around 15:00, while flying over the Ritzingeralp region, the aircraft entered a significant downdraft zone. Witnesses observed the glider flying parallel to the slope before it suddenly pitched over the left wing, entered a left-hand spin, and crashed into a rock formation. The impact destroyed the aircraft and resulted in the death of the pilot.

The investigation

Investigators examined the wreckage and the pilot's flight history. The aircraft's structural components, including the wings and tailplane, were found to be correctly installed with no evidence of mechanical failure. The weight and center of gravity were within permissible limits. Medical examinations of the wreckage revealed traces of vomit on the pilot's flight suit and the fuselage, suggesting the pilot had become unwell during the flight. Additionally, the investigation reviewed the pilot's training, noting that while he was a licensed glider pilot, he had only received a brief 23-minute alpine orientation flight just three days prior to the accident.

Findings

  • The primary cause of the accident was the undershooting of the minimum flying speed at a very low altitude, estimated to be between 70 and 120 meters above the ground.
  • The pilot's limited experience with mountain soaring contributed to the inability to recover from the loss of airspeed.
  • The pilot's physical unwellness, evidenced by vomiting during the flight, likely impaired his attention and reaction to the descending air currents.
  • The aircraft entered a left-hand spin after failing to maintain sufficient airspeed while navigating a downdraft.

Probable cause

The accident was caused by the aircraft falling below its minimum flying speed at a low altitude, compounded by the pilot's lack of mountain flying experience and physical illness during the flight.

Frequently asked questions

What happened in the 1972-08-02 ALEXANDER SCHLEICHER OHG SEGELFLUGZEUGBAU K 8B accident near Ritzingeralp, VS, CH?

A glider pilot lost control of his aircraft after entering a downdraft zone, resulting in a fatal spin and the destruction of the aircraft.

What aircraft was involved and where did it happen?

The accident on 1972-08-02 involved a ALEXANDER SCHLEICHER OHG SEGELFLUGZEUGBAU K 8B, registration HB-810, at Ritzingeralp, VS, CH.

What was the probable cause of the accident?

The accident was caused by the aircraft falling below its minimum flying speed at a low altitude, compounded by the pilot's lack of mountain flying experience and physical illness during the flight.

Investigation report by the Swiss Transportation Safety Investigation Board (STSB / SUST). Original record: https://www.sust.admin.ch/inhalte/AV-berichte/810.pdf. This page is a structured re-presentation; facts and quotes are in the Swiss Transportation Safety Investigation Board (STSB), Switzerland.

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