What happened
On June 1, 2001, a Grob Astir CS 77 glider, registration I-BZUM, was performing a local training flight via aero-tow. After releasing from the tow plane at approximately 1,000 meters, the glider encountered intense localized downdrafts. The loss of altitude was so significant that the pilot was unable to return to the airfield, necessitating an emergency landing in a wooded area near Tavernerio. The impact with trees caused extensive damage, including a broken right wingtip, a torn left wing leading edge, and a destroyed canopy. The pilot escaped the wreckage uninjured.
On November 3, 2001, a Piper PA-34-200T aircraft, registration I-PREM, was conducting a commercial pilot training mission at Biella Airport. During a simulated engine failure maneuver, the crew failed to notice that the landing gear had not extended. The crew only realized the gear lights were off during the final approach. Due to the low altitude and lack of margin for a go-around, the crew performed a belly landing. The aircraft sustained damage to the propellers, antennas, flaps, and fuselage. There were no injuries to the two occupants.
The investigation
The ANSV examined the mechanical and operational circumstances of both events. For the glider, investigators analyzed the meteorological conditions, specifically the presence of Föhn winds, and the flight planning. For the Piper aircraft, the investigation focused on the landing gear's extension mechanism and the crew's monitoring of the cockpit indicators during the simulated emergency procedures.
Findings
- The glider accident was caused by strong downdrafts encountered immediately after release, compounded by the pilot's inadequate flight planning regarding local wind conditions.
- The Piper accident was caused by a malfunctioning hydraulic pump that prevented the gear from extending and locking. This was contributed to by poor coordination between the pilot and instructor, which resulted in a failure to notice the gear status in time to execute a go-around.