The aircraft was flying at 2,500 ft when the propeller suddenly detached. The pilot was able to execute a forced landing with no further damage to the aircraft. The detachment had been caused by a fatigue crack which had developed in the tapered end of the crankshaft. This problem had been recognised in 1939 but had not resulted in any mandatory requirements. The Light Aircraft Association (LAA) have now mandated a repetitive visual and dye-penetrant inspection of the crankshaft for corrosion and cracking.