Fatal Beechcraft Bonanza crash at Bistinen Pass

Casualties unknown • Bistinenpass, VS, CH

A single-engine Beechcraft B-35 Bonanza crashed in the Swiss Alps in 1965, resulting in the death of the pilot due to deteriorating weather conditions.

What happened

On the morning of April 9, 1965, a pilot departed from Ascona airfield, intending to fly to Geneva via the Simplon Pass. The flight was originally planned for the previous day but had been delayed due to poor weather in the Valais region. After departing at 09:24, the aircraft was observed flying near Camedo at approximately 09:30. At 09:45, the sound of an aircraft engine was heard through dense fog near the Simplon Pass, but the aircraft subsequently disappeared.

Following the aircraft being reported overdue, a search operation involving French and Italian services was initiated. The wreckage was not located until April 30, found approximately four kilometers west of the Simplon at the Bistinen Pass. The pilot's body was recovered from the debris the following day.

The investigation

An investigation was launched in May 1965 following the discovery of the wreckage. Due to heavy snow, the initial inspection took place on-site, with a second examination conducted in July after the snow had melted. Investigators examined the wreckage, which included the fuselage, wings, and tail, noting that the engine and propeller had been significantly impacted. The investigation also reviewed the pilot's extensive flight experience, which included over 800 hours of flight time and significant mountain flying experience, as well as the meteorological conditions at the time of the accident.

Findings

  • The aircraft, a Beechcraft B-35 Bonanza with registration HB-ECW, was destroyed upon impact.
  • The pilot sustained fatal injuries.
  • At the time of the accident, the region was experiencing a north-stau weather pattern, characterized by heavy cloud cover and fog at the Simplon Pass.
  • The investigation determined that the pilot likely continued the flight into weather conditions that no longer permitted safe visual flight.
  • It is suspected that the pilot either lost visual contact with the ground while flying through a fog bank or flew too close to the snow-covered terrain while attempting to stay below the cloud ceiling.

Probable cause

The pilot continued the flight into deteriorating weather conditions, specifically flying into fog and low clouds that prevented safe visual flight rules (VFR) operations.

Frequently asked questions

What happened in the 1965-04-09 BEECH AIRCRAFT CORPORATION B35 accident near Bistinenpass, VS, CH?

A single-engine Beechcraft B-35 Bonanza crashed in the Swiss Alps in 1965, resulting in the death of the pilot due to deteriorating weather conditions.

What aircraft was involved and where did it happen?

The accident on 1965-04-09 involved a BEECH AIRCRAFT CORPORATION B35, registration HB-ECW, at Bistinenpass, VS, CH.

What was the probable cause of the accident?

The pilot continued the flight into deteriorating weather conditions, specifically flying into fog and low clouds that prevented safe visual flight rules (VFR) operations.

Investigation report by the Swiss Transportation Safety Investigation Board (STSB / SUST). Original record: https://www.sust.admin.ch/inhalte/AV-berichte/265.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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