The Mustang and the Merlin. So right did the combination prove that they are now synonymous. But it was by no means always certain it would produce the long-range escort fighter which proved so influential in the European theatre. What was the reality behind the legend?
The traditional story of how the Rolls-Royce Merlin came to be united with the North American Mustang is one of the best-known in aviation. Over the years, it has come to symbolise many things to different people, a lot of them contradictory. In reality, the tale is more complex and interesting than the narratives the history has been shoehorned into. Even though by the autumn of 1942 it was a certainty that the Mustang’s future was Merlin-powered, it was by no means clear the aircraft would get the high altitude-rated Merlin 61 that allowed it to escort the 8th Air Force ‘heavies’ all the way to Berlin. Many saw the aircraft’s true value in low-level roles and sought to steer it towards the same Merlin fitted to some Curtiss P-40 models.