What aircraft was involved and where did it happen?

The accident on 1964-07-13 involved a AERO VODOCHODY AEROSPACE A.S. AE-45, registration VP-KRF, at Val Tremola, TI, CH.

What was the probable cause of the accident?

The pilot failed to maintain a sufficient altitude for traversing the Alpine terrain, likely due to being deceived by the local landscape and failing to plan for a safe clearance over the mountains.

Fatal Crash in Val Tremola Involving Super Aero 45

A Super Aero 45 aircraft crashed in the Val Tremola, resulting in one fatality and leaving the pilot severely injured after the aircraft struck terrain.

What happened

On July 13, 1964, a Super Aero 45, registration VP-KRF, departed from Lugano-Agno airport for a flight to Zurich. The aircraft was being operated by a pilot traveling from East Africa to Europe, accompanied by one passenger. The flight was intended to traverse the Alps via a route that would save time.

At approximately 11:30, the aircraft entered the Val Tremola at an altitude of roughly 1,800 meters. While flying through the narrow valley, the aircraft was observed by witnesses to be flying at a very low altitude relative to the terrain. As the aircraft progressed, it banked to the right, making contact with the eastern slope of the valley, which caused it to crash into the ground. The impact resulted in the total destruction of the aircraft. The passenger sustained fatal injuries and died during transport from the site, while the pilot suffered severe injuries and temporary memory loss.

The investigation

The Swiss investigation examined the flight planning and the environmental conditions at the time of the accident. The investigation established that the weather was clear with good visibility of 15–20 km and light winds. The aircraft, a twin-engine metal construction model, was found to be in good technical condition with no mechanical failures contributing to the crash.

The investigation also reviewed the pilot's preparation. While the pilot had received information regarding the height of the Gotthard Pass in meters, the commission noted that the pilot's familiarity with feet rather than meters might have influenced his perception of the terrain. Furthermore, the investigation looked into the terrain configuration, specifically the area near Motto di Dentro, which can create a visual illusion for pilots unfamiliar with the local topography.

Findings

The primary cause of the accident was that the pilot failed to maintain a pre-calculated safe altitude required for traversing the Alps.
The pilot entered the narrow Val Tremola at an insufficient height, failing to recognize the moment when a turnaround was still possible.
The terrain configuration likely caused a visual deception; the plateau at Motto di Dentro may have appeared to be the pass summit to a pilot without specific local knowledge.
The pilot did not plan or execute a flight path over unfamiliar and difficult terrain using a predetermined safe altitude.