History of the Flight
The pilot, aged 19 with 46 total flying hours (2 on type), intended to fly from Barton Aerodrome to Sherburn-in-Elmet. Pre-flight inspection confirmed sufficient fuel. After satisfactory pre-flight and power checks, with magneto drops within limits, flaps were set to 15 degrees for takeoff on Runway 09.
Part-way into the takeoff roll, the engine briefly shuddered and coughed. The pilot checked the choke control, which was in the OFF position. The shuddering ceased, and as airspeed reached 40 kt, the pilot continued the takeoff. The climb was normal until approximately 300 ft, when the engine again shuddered and lost power. The pilot completed raising the flaps, reducing the climb rate further. He confirmed the throttle was fully open, choke OFF, fuel ON, and magneto switch set to '1+2'.
The aircraft began losing height. The pilot turned left toward a sports field but realized it was unreachable, then headed toward a gap between two houses and transmitted a distress call. The aircraft struck telephone wires as the pilot attempted to avoid a house, coming to rest in a domestic garden with the forward section completely detached. The passenger escaped and freed the semi-conscious pilot from the wreckage.
Powerplant Description
The high-wing aircraft has fuel tanks in the leading edges of the inboard wing sections, supplying fuel by gravity feed to a selector valve behind the engine. A mechanical fuel pump is mounted at the front of the engine crankcase. A fuel bleed return line between the downstream side of the pump and the fuel drain sump maintains a steady fuel flow, reducing the propensity for vapour lock after extended low-power running.
Wreckage and Engine Examination
All damage to the engine and fuel supply system was consistent with impact. A strip-examination of the Rotax 912ULS engine, conducted with the manufacturer's UK agent, found no evidence of internal engine defects or mechanical failure.
Discussion
The absence of engine mechanical defects cast suspicion on the fuel supply. No other aircraft in the area reported similar problems, discounting contamination of the local bulk fuel supply. Vapour lock was considered unlikely as the engine had not run at low power for an extended period. Other possibilities include water contamination, debris in the fuel system, or carburettor icing, but there was insufficient evidence to determine which was most likely. Previous power loss incidents on this aircraft type have been attributed to fuel outlets becoming uncovered during uncoordinated turns with low fuel levels; however, in this case the aircraft had significant fuel on board and was not manoeuvring.