Due to increasing problems with US customs we are no longer able to dispatch books to the USA.

Few will argue that the North American Mustang powered by the Rolls-Royce Merlin engine was America’s finest all-round combat aircraft of the Second World War. Specified and ordered in 1940 by the British Air Commission during its search for suitable American aircraft to supplement the types then in service with the Royal Air Force, it was produced in the remarkably short time of 120 days. Unfortunately, its low-rated Allison engine was incapable of permitting the airframe’s advanced aerodynamic features to be exploited to the full, with the result that the RAF relegated it to close-support duties and the Spitfire still reigned supreme in the medium- and high-altitude fighter roles.

This story is about the rebirth of the Mustang and the role played by Rolls-Royce in that event. The greatest part by far was played by the Company’s Experimental Flight Test Establishment at Hucknall in Nottinghamshire. Parented by Derby, yet completely autonomous with the means of installation design, development and manufacture, it was a unique organisation among aero-engine manufacturers.

During the telling of the story much use has been made of contemporary memoranda associated with the project and, in most cases, these are reproduced at the appropriate juncture in the story. In some cases, these writings, apart from referring to a specific point of issue, also give information on other contemporary matters. Where these matters can be considered in some way relevant to the story or reveal an attitude of a party involved, or if they are just simply interesting or amusing, they have been left undisturbed. Irrelevant paragraphs have been omitted, as have the writers’ names. The latter is revealed in the document reference at its heading and can be deciphered by referring to the table explaining the Rolls-Royce reference system. If nothing else the correspondence reveals the close relationship that existed between Rolls-Royce, the Air Staff and other parties during those critical times. 

The reproduction of such documents has its drawbacks in that the names of various personalities consistently crop up without reference to their title or role in the events. To avoid interfering with the flow of the text, I have resorted to footnotes to provide identification. Most of what will be read has been obtained from Company archival material though occasional use has been made of other sources in order to portray a wider view of events.

These were the paramount years in the Company’s history and no other civilian aeronautical organisation could field a first-eleven to match the likes of Hives, Elliot, Lovesey, Hooker, Rubbra and Lappin, along with Hucknall’s Dorey, Hart, Challier, Harker and Shepherd. Willoughby ‘Bill’ Lappin, Hives’ personal assistant, who divided his time between the Nightingale Road factory and the Company’s London office in Conduit Street, plays a major part in the story being the link man between the Company and the Air Ministry, Royal Air Force, North American Aviation, the American Embassy and the US Army Air Force. He knew everybody that mattered and they knew him.

This publication also enables the opportunity to be taken to reveal the story behind Rolls-Royce’s unsuccessful attempt to produce an aircraft to its own design based on certain Mustang features. Strange that in the middle of a war, which was demanding all of the Company’s resources in producing and developing an established range of engines, along with new designs, it should embark upon a project so radical. The decision was more remarkable when one considers that Hucknall had been established a mere eight years earlier by engine-minded men. During those eight years a great deal of experience with airframes had been accrued throughout the design and installation of powerplants and the necessary structural alterations involved, so much so that by the end of 1942 the draughtsmen and stressmen felt confident in taking on the production of an indigenous design. That they didn’t entirely succeed was not their fault – nothing changes faster than technology during a war.

Since the original publication and reprint of this book more information has come to light to expand the story. From the National Archive at College Park, Maryland, the files of Wright Field have yielded information concerning the early moves to produce two-stage Merlins at Packard, the initial moves to install the Merlin in the Mustang, and proposals for its installation in other American aircraft. These documents have been given a separate Appendix. Some of these additions drift away slightly from the Rolls-Royce side of the story, but have been included to give the reader a better insight into what was happening in America when it realised the potential of the two-stage Merlin. From the Rolls-Royce archives, now held and administered by the Rolls-Royce Heritage Trust, come more illustrations of projected installations using Mustang parts.