What happened
On 9 July 2005, a Scheibe SF25B, registration G-AXEO, was performing a private cross-country flight from Milfield Airfield in Northumberland. The pilot had planned a one-hour flight and had opted not to refuel prior to departure, as the remaining 15 litres of fuel were deemed sufficient for the intended duration.
Following a brief delay while a glider was retrieved from the airfield, the pilot commenced the takeoff roll. Approximately two-thirds of the way down the runway, the aircraft became airborne, reaching an altitude of between 20 and 30 feet. At this point, the pilot noted a progressive loss of engine power, which subsequently led to a complete engine failure. Unable to maintain altitude or return to the remaining runway, the aircraft descended. During the landing, the propeller struck a perimeter fence, and the left wing made contact with a small tree. The aircraft came to rest in a disused section of the airfield. The pilot was able to exit the aircraft unassisted, and there were no injuries reported.
The investigation
The investigation examined the extensive damage to the aircraft, which included a broken left wing spar, a cracked right wing, a twisted rear fuselage, and a damaged propeller. The aircraft was subsequently declared a total loss.
Investigators evaluated two potential causes for the engine failure: carburettor icing and fuel system vapour lock. While the Chief Flying Instructor suggested that the carburettor heat system's performance might have been compromised by heat dissipation from the engine, meteorological data showed that the conditions were not conducive to carburettor icing. The ambient temperature was +25°C with a dew point of +13°C and 51% humidity.
Findings
- The engine showed no evidence of internal damage during inspection.
- The investigation determined that vapour lock in the fuel system was the most likely cause of the engine failure, as the high ambient temperature and the warm engine state created ideal conditions for such an occurrence.
- The aircraft sustained damage beyond economic repair.