What happened
On 13 December 2001, a Rans S-12XL, registration G-BZAO, was conducting a PFA Permit Air Test at Kirkbride Airfield, near Carlisle. The aircraft, which was the first of its type registered in the UK, was being operated by its owner. After completing several successful circuits in fine weather, the pilot commenced a new take-off from Runway 10 with a passenger acting as an observer.
During the climb, at an altitude of approximately 150 to 200 feet, the engine power unexpectedly dropped to roughly one-third of its maximum output. Because the aircraft lacked the altitude to clear the road at the end of the runway and did not have enough runway remaining for a straight landing, the pilot executed a left turn. The aircraft subsequently landed on soft, cultivated ground adjacent to the runway. The impact was heavy, causing the nose landing gear to dig into the earth, which forced the aircraft to pitch forward onto its nose. There were no injuries to the two occupants.
The investigation
Investigators examined the aircraft and the engine following the incident. The owner's inspection of the Rotax 582 engine and its associated components revealed no obvious malfunctions, and the engine remained operational despite the power loss. The fuel lines were confirmed to contain fuel, and the engine was able to turn freely.
During the examination of the fuel system, a small quantity of fine white plastic debris was discovered on the fuel filter element. This material was consistent with the composition of the aircraft's fuel tanks. The investigation noted that the process of drilling the plastic tanks to install outlet pipes can inadvertently leave behind small plastic chips. These fragments can migrate through the feed lines and potentially cause a restriction in fuel flow.