What happened
On 3 December 2011, a Robin DR-300/180R, registration D-EGSK, operated by Aeroclub de Toledo, departed from runway 30 at Lillo Aerodrome, Spain. The flight was a private general aviation operation intended to check the aircraft's performance prior to glider towing duties.
During the initial climb, at an altitude of approximately 100 feet, the engine stopped abruptly. The pilot, noting no immediate instrument or control abnormalities, executed an emergency landing in a flat crop field located roughly 300 meters beyond the runway end. The impact caused significant damage to the aircraft's landing gear, wing, and nose section, including the propeller and mount. Both occupants, the pilot and one passenger, were uninjured and able to exit the aircraft under their own power.
The investigation
The CIAIAC examined the aircraft's maintenance history, the fuel system, and the procedures performed prior to departure. The investigation noted that the aircraft had been stored in a hangar and had seen minimal use in the months preceding the accident.
Investigators focused on the refueling and drainage process. Before takeoff, the main tank had been refilled with 51 liters of fuel, while the reserve tank remained empty. Although the pilot had drained the main tank and the gascolator as part of the pre-flight inspection, the investigation looked into the possibility of fuel contamination. Additionally, the investigation identified a specific issue with the ignition switch, which featured a metal screen that could potentially ground the magnetos if improperly positioned; this finding later prompted a mandatory service bulletin from the manufacturer.
Findings
- The aircraft was properly maintained and held a valid airworthiness certificate.
- The pilot held all necessary licenses and ratings for the operation.
- The intake of water from the main fuel tank caused the sudden engine stoppage.
- Environmental factors, including temperature fluctuations while the aircraft was parked and the partially filled fuel tank, likely led to water condensation.
- Because the fuel drainage was performed after the tank had been refilled, a fuel-water emulsion had formed that appeared homogeneous during the initial check but separated during flight, allowing water to enter the engine.