Incident Overview
On 12 March 2002, at 12:30 UTC, a Piper PA-18, registration I-BALM, sustained damage when it nosed over after landing at the Tonale airstrip near Passo del Tonale, in the municipality of Vermiglio, Trentino, Italy. The aircraft was operated by Transavio s.r.l. and was conducting aerial work in the form of fire lookout reconnaissance.
Sequence of Events
The aircraft departed from Venegono Airport (VA) with a pilot and an observer on board. After completing reconnaissance over the provinces of Varese and Como, the flight proceeded to Valtellina and then to Alta Valcamonica. The pilot, experiencing physiological needs, decided to land at the Tonale airstrip, which was only four minutes away. The pilot later stated that the airstrip was known to him as a secondary base for firefighting operations and that he was familiar with its location.
Aware that snowfall had occurred in the area about a week earlier, the pilot performed a low pass before landing to assess runway conditions. The slope adjacent to the runway appeared patchy with snow and dry grass. Puddles of melted snow on the edge of the runway seemed shallow. The snow on the runway appeared compact and uniform, with numerous footprints on the surface. The pilot executed the final approach at minimum speed in order to stop in the shortest possible distance.
Upon touchdown, the main landing gear wheels sank more than 60 centimeters into wet, heavy snow. This abrupt deceleration caused a pitching moment that resulted in the aircraft nosing over.
Aircraft and Pilot Information
The aircraft was a Piper PA-18-150 (serial number 18-7809035, built in 1977), a single-engine taildragger with two seats in tandem. It was powered by a Lycoming O-320-A2B engine producing 150 hp. Maximum takeoff weight was 794 kg.
The pilot was a 45-year-old Italian male holding a valid commercial pilot license and a valid medical certificate. He had accumulated 5,200 total flight hours, of which 3,100 were on taildragger aircraft.
Injuries and Damage
No injuries occurred to the pilot or observer. The aircraft sustained damage to the propeller and the right wing strut, as documented in photographic evidence.
Probable Cause
The investigation identified the probable cause as an erroneous evaluation of the suitability of the landing area.
Weather Conditions
At the time, visibility was good and wind was absent.