What happened
On April 12, 1971, an M-100-S glider, registration I-LMIO, departed from Calcinate for a training flight. During the flight, the pilot headed toward Monte Ceneri, reaching an altitude of approximately 1,250 meters. While attempting to return toward Agno airport, the aircraft encountered significant atmospheric disturbances, specifically strong downdrafts of 2 to 3 meters per second. These conditions forced the pilot to terminate the flight prematurely and seek an emergency landing in an unsuitable area near the border of Bedano and Taverne.
As the pilot attempted to navigate toward a landing site, the aircraft had to maneuver around buildings and overhead obstacles, including power lines. A tailwind of 10 to 20 knots further complicated the approach. During the landing turn, the glider struck an electrical cable, which caused the aircraft to lose altitude and ultimately left the glider suspended in the wires. The pilot escaped the incident uninjured, though the aircraft sustained heavy damage to the fuselage and left wing, and a wooden pole was crushed.
The investigation
The investigation examined the pilot's flight experience, the airworthiness of the M-100-S, and the environmental conditions at the time of the accident. Investigators reviewed the pilot's training records, noting recent flight activity and a valid license. The aircraft's maintenance and weight and balance were also verified, with no pre-existing mechanical defects found. The investigation also assessed the terrain, noting that the area is heavily populated and densely covered with overhead wires and high-voltage lines, making off-field landings extremely hazardous.
Findings
- The primary cause of the accident was the pilot's failure to adequately account for local thermal conditions and wind direction.
- The decision to perform an emergency landing in the field was made too late.
- The pilot did not sufficiently consider the difficult terrain and the presence of overhead obstacles when executing the landing.
- A significant tailwind contributed to the difficulty of the landing maneuver and the subsequent collision with the power lines.
- The impact resulted in the destruction of a 220/380 V electrical cable and a telephone line, as well as damage to several utility poles.