What happened
On 21 July 2006, a Europa aircraft, registration G-TAGR, departed from RAF Syerston, Nottinghamshire, for a private flight. Shortly after takeoff, the pilot observed that the engine was not reaching its expected maximum RPM. While the aircraft initially maintained a steady climb, the engine began to misfire and lose speed once the aircraft climbed through 200 ft.
In an attempt to rectify the rough running, the pilot reduced the power setting, which temporarily stabilized the engine. However, upon attempting to increase power for a climb, the engine failed to respond and began misfiring severely. As the aircraft descended through 200 ft, the pilot executed a forced landing in a crop field. During the landing, the aircraft struck the ground in a nose-down attitude, causing the nose landing gear to collapse and resulting in significant damage to the wing mounts and lower fuselage. There were no injuries to the two occupants.
The investigation
The investigation examined the engine, fuel system, and ignition components. The ignition system cables were found to be in good condition, with no evidence of cracking or damage. While the possibility of carburettor icing was considered due to the low power settings used during the initial takeoff phase, no technical defects were identified in the induction system.
Testing of the fuel system revealed that the fuel supply was being drawn from the left lobe of the fuel tank. Although debris was found in the fuel filter, the supply from each side of the tank was capable of providing more than double the engine's maximum fuel consumption rate. The investigation also noted that the fuel lines, which were made of braided steel, lacked the insulating sleeves recommended by the manufacturer to prevent heat transfer.
Findings
- The engine's loss of power and subsequent rough running was likely caused by fuel vapour lock, which interrupted the fuel flow.
- The use of un-insulated fuel lines in a high-heat area of the engine compartment, combined with high ambient temperatures and humidity, facilitated this vapour lock.
- The heavy landing and subsequent gear collapse were caused by a nose-down attitude and the aircraft's impact with the upslope of the field.