Scheibe SF25B, G-AXEO
The pilot planned to fly the aircraft once it had returned from a previous flight. Prior to take off the aircraft had to hold for 5 mins, on dry grass, while a glider that had just landed was recovered. During this period the engine speed was maintained at 1,100 rpm. The OAT was +25°C. Soon after take off there was a progressive reduction in engine power. Being at about 80 ft, the pilot realised that he was too high to land in what remained of the airfield ahead. The engine then stopped completely and the aircraft descended striking the airfield boundary fence before coming to rest. The pilot vacated the aircraft unassisted and without injury. Given that the engine was already warm from its previous flight and the normal air supply to the carburettor would have provided very warm air as a consequence of its low flow rate through the engine compartment in the absence of any ram effect. It is therefore considered that these conditions were ideal for the formation of a vapour lock in the fuel line.
Scheibe SF25B, G-AXEO 2-06.pdf (211.52 kb)