What happened
On July 19, 2002, at approximately 12:27 local time, an Aerospatiale Socata Rallye R-180-T, registration EC-DPI, was performing its third glider towing flight of the day at La Nava Aerodrome in Corral de Ayllón, Segovia. The aircraft was towing a L-13 Blanik glider when, roughly one minute after takeoff from runway 36, the engine experienced a sudden drop in power.
At the time of the incident, the aircraft was at an altitude of approximately 200 feet, flying on a heading of 360° and about 1,000 meters past the northern boundary of the airfield. Following the initial power loss, the pilot executed a gentle 90-degree right turn to attempt a return to the airfield. During this maneuver, the power loss recurred and failed to recover, prompting the pilot to release the glider.
The pilot subsequently performed an emergency landing in a harvested cereal field. The aircraft traveled approximately 250 meters along the ground on a heading of 150° before striking a dirt path characterized by two ditches and a canalized trench. The impact caused significant damage to the propeller, the lower fuselage, the wings, and the landing gear, which suffered a broken right main leg and bent remaining struts.
The investigation
The investigation focused on the engine's performance and the fuel system. While the propeller damage indicated that the engine was not producing power at the moment of impact, a mechanical inspection of the engine revealed no identifiable mechanical failure. Functional testing of the engine could not be completed because the carburetor was damaged during the landing, and the fuel had been drained by airfield personnel prior to the inspection.
Investigators examined the fuel system, including the fuel selector valve and delivery lines, finding them to be in good condition. The pilot confirmed that the fuel selector had not been moved during the flight. Additionally, the pilot noted that the aeroclub's standard procedure involved filling the tanks to capacity the previous night, and a pre-flight check on the day of the accident had confirmed correct fuel and oil levels.
Findings
- The engine experienced a sudden loss of power during the initial climb and a subsequent, non-recovering loss of power during a turning maneuver.
- The aircraft struck ground obstacles (ditches and a trench) during the emergency landing.
- An interruption in the fuel supply to the engine was identified as the most probable cause, although the specific origin of the interruption could not be determined.