The Gardan Horizon’s pilot reported that while conducting pre-flight checks, the fuel drain sample contained water, which he said was common for this aircraft. He drained the fuel until he obtained a clear sample, then took further samples, including after refuelling, until satisfied that the tanks were free from contamination. After takeoff from Coventry, while climbing to 2,000ft, the engine began to run rough. The pilot turned on the fuel pump and informed ATC he would be returning to Coventry, but the rpm continued to reduce and the engine subsequently stopped. He selected a different fuel tank and restarted the engine, but the aircraft could not maintain height. He chose a field in which to land, electing to keep the undercarriage retracted due to the ground conditions and to maximise the glide range (the Horizon’s flaps extend fully when the landing gear is lowered). The forced landing was successful and neither occupant was injured, although the aircraft suffered damage to its engine, propeller, lower fuselage and landing gear. The pilot considered that the engine failure might have been caused by water contamination in the fuel, carbon build-up on the spark plugs, or some other problem.
Like any aircraft, the Gardan Horizon can be subject to water in the fuel