What happened
On July 20, 1970, at approximately 13:55, a Cessna 175, registration HB-CRN, departed Locarno Airport for a commercial sightseeing flight. The aircraft was carrying the pilot and two passengers. During the flight, the aircraft followed the northern shore of Lake Lungo before turning south near Muralto and crossing parts of Locarno.
As the aircraft approached the area south of the Lido, it turned eastward, moving away from the shoreline and out over the lake toward the Magadino Plain. At an altitude estimated between 100 and 250 meters, the aircraft entered a steep descent. At 14:02, the aircraft struck the water approximately 2 km south of Minusio and sank within seconds. All three occupants were killed, and the aircraft was destroyed. There was no damage to third-party property.
The investigation
Investigators examined the aircraft's maintenance history and the pilot's credentials. The Cessna 175 had undergone its 100-hour inspection recently, and the pilot was highly experienced, with approximately 2,000 flight hours. Toxicology reports confirmed that the pilot was not under the influence of alcohol or carbon monoxide at the time of the accident, and medical examinations ruled out sudden incapacitation or health-related issues for the passengers.
While some witnesses reported hearing an engine pop or a drop in power, investigators determined this was likely caused by a sudden reduction in throttle rather than a mechanical failure. The investigation also looked into the possibility of the pilot losing control due to the lack of a visible horizon over the water.
Findings
At the time of the accident, weather conditions were deteriorating rapidly. Heavy rain and low visibility were present, with some reports indicating that the horizon was nearly impossible to discern. The investigation established that the pilot continued the flight under insufficient VFR (Visual Flight Rules) conditions.
Because the aircraft was flying over a smooth water surface in poor visibility, the pilot likely struggled to maintain an accurate height above the ground. The investigation concluded that the lack of visual references, combined with the worsening weather, led to the fatal collision with the lake surface.