What happened
On January 12, 2003, a Schleicher ASK 16 motor glider, registration D-KGOR, was conducting a local flight from the Rivoli di Osoppo airfield in Italy. During the return phase of the flight, at an altitude of approximately 1,500 feet, the engine began to malfunction and subsequently shut down.
Unable to restart the engine and facing insufficient altitude to return to the home airfield, the pilot identified a nearby field for an emergency landing. However, as the aircraft approached the landing site, the pilot realized the usable runway length was shorter than initially estimated due to trees at the margins and a depression in the terrain that had been obscured by a thin layer of snow. The pilot proceeded with the landing, attempting to utilize the available 250 meters of the field. Upon contact with the frozen ground, the aircraft experienced a left yaw and began to skid. The landing gear collapsed, and the aircraft eventually came to a stop against nearby vegetation. The two occupants, the pilot and a passenger, were uninjured, though the aircraft sustained damage to the landing gear, the right wing, and the fuselage.
The investigation
The ANSV investigation focused on the mechanical failure of the powerplant and the conditions of the landing site. Technical examinations of the engine, conducted by the manufacturer, identified that the failure of the secondary winding in the Slick P/N 4230 ignition magneto caused the loss of energy to the spark plugs, leading to the engine shutdown. The investigation confirmed that the engine was equipped with a single ignition system, which is permitted under EASA CS-22 certification standards for powered sailplanes.
Maintenance records showed that the magneto had undergone its biennial inspection in November 2000 and had been reinstalled following a Service Bulletin approximately three hours before the accident. The investigation also noted that the reduced braking effectiveness during the landing roll was caused by the low coefficient of friction provided by the thin layer of ice and the slight downward slope of the landing area.