What aircraft was involved and where did it happen?

The accident on 2001-05-06 involved a Grob Twin Astir,, registration I-IVAS, at Monte Marzola (Trento) Aliante Grob Twin Astir, IT.

What was the probable cause of the accident?

The incidents were caused by a variety of factors including mechanical wear (piston seals and steering flanges), pilot error (inadequate braking and over-control), and poor flight planning (fuel management).

ANSV Summary of Aviation Incidents: 2000–2002

A compilation of Italian aviation investigation reports detailing various incidents involving light aircraft, ranging from landing gear failures to fuel exhaustion.

What happened

Between June 2000 and April 2002, several notable aviation incidents occurred across Italy involving various light aircraft types:

On June 19, 2000, a Piper PA-34-200, registration I-MIMU, performing a training flight, experienced a nose gear retraction during landing at Palermo Punta Raisi. After the pilot and instructor observed a discrepancy in the landing gear lights, the tower confirmed the gear appeared extended, but the nose gear collapsed upon touchdown, causing the aircraft to slide for approximately 100 meters.
On August 12, 2000, a Cessna 150, registration I-FFSH, experienced engine power loss near Santa Maria Nuova di Bertinoro. The flight, which had exceeded its planned duration, resulted in an emergency landing in a field due to fuel exhaustion.
On May 6, 2001, a Grob Twin Astir glider, registration I-IVAS, crashed into a wooded area near Monte Marzola after losing altitude following separation from its tow plane.
On February 9, 2002, a Socata TB 9, registration I-IAEO, overran the runway at the Sabaudia airpark after an unsuccessful attempt to brake during landing.
On April 17, 2002, a Piper PA-28-140, registration I-ICES, experienced a loss of control during a touch-and-go maneuver at Biella Cerrione. A heavy landing triggered a severe bouncing effect (porpoising), leading to the failure of the nose gear and the aircraft veering off the runway.

The investigation

The ANSV examined the mechanical components and flight logs for each event. For the I-MIMU incident, investigators inspected the nose gear assembly and found that a broken steering flange caused the spherical pin to dislodge from its tracks. In the I-IVAS glider accident, technical inspections of the landing gear piston revealed a worn seal. For the I-ICES incident, the investigation focused on the pilot's longitudinal control and the impact forces during the landing sequence.

Findings

The primary cause of the I-MIMU gear failure was a mechanical failure in the steering flange resulting from previous excessive ground maneuvering.
The I-FFSH fuel exhaustion was attributed to inadequate flight planning and a failure to verify remaining fuel levels.
The I-IVAS glider failure was caused by a worn seal in the landing gear piston, preventing the gear from locking.
The I-IAEO runway excursion was caused by the pilot's failure to apply sufficient braking via the rudder pedals.
The I-ICES incident was caused by a heavy landing and subsequent over-control by the student pilot, leading to the nose gear collapse.