What happened
On 14 April 2007, a Mainair Blade microlight, registration G-MZMB, was conducting a series of private flights from Higher Barn Farm, a grass airstrip near Preston. After completing an initial solo circuit to verify the aircraft's performance, the pilot prepared to fly with a passenger. Prior to this departure, the pilot had refuelled the aircraft, mixing two-stroke oil with petrol in the 24-litre tank.
During the flight, witnesses on the ground observed the aircraft approaching at a low altitude. They noted the engine sound began to 'hunt' before the engine ceased operation entirely. Following the engine failure, the pilot attempted a forced landing in a nearby field. However, the aircraft''s airspeed decayed, causing it to stall after clearing a large tree. The microlight descended rapidly and struck a boundary hedge and thicket consisting of holly and bramble trees.
Both the pilot and the passenger sustained serious injuries. The pilot suffered severe facial trauma due to an impact with a tree trunk, and both occupants were evacuated to a hospital.
The investigation
Investigators examined the wreckage and the engine components to determine the cause of the power loss. The Rotax 462 engine and its ignition system were found to be in serviceable condition, and there was no evidence of mechanical failure or loss of compression. The fuel pump and fuel filter were also found to be free of debris and functioning correctly.
Analysis of the fuel system revealed that the fuel tank contained only approximately two litres of fuel at the time of the accident. Because the flexible fuel feed pipe inside the tank had been deflected to one side, it was unable to draw fuel from the lowest point of the tank. This led to fuel starvation.
Findings
- The engine stopped due to fuel starvation caused by a lack of available fuel.
- The fuel feed pipe was positioned such that it could not access the remaining fuel in the tank.
- The pilot was unable to select a suitable landing area because the engine failure occurred at a very low altitude.
- The aircraft stalled and struck the thicket after the airspeed dropped during the approach.