Miles Master
The Miles Master was a British two-seat advanced trainer of the Second World War, built by Phillips & Powis Aircraft — the company renamed Miles Aircraft in 1943 — at Woodley, South Marston and Doncaster. Designed to match the performance and handling of the RAF's Spitfire and Hurricane fighters, it first flew on 31 March 1939 and entered service shortly before the war. Production totalled 3,249 aircraft in three marks distinguished chiefly by their engines: the Rolls-Royce Kestrel (Master I), the Bristol Mercury (Master II) and the Pratt & Whitney Twin Wasp Junior (Master III). Masters trained pilots at Advanced Flying Units, towed gliders and targets, and served with several Allied air forces; no complete example survives.
Why It Mattered
The Miles Master was an advanced trainer built to prepare British pilots for the high-speed monoplane fighters of its day. Miles designed it to match the performance and handling of the frontline fighters of the period, the Supermarine Spitfire and the Hawker Hurricane. The order that launched production, for 500 aircraft placed on 11 June 1938 after the rival de Havilland Don had failed, was claimed at the time to be Britain's largest ever contract for a training aircraft. It reached its users just in time: the first production aircraft flew on 31 March 1939, and the type had entered RAF service shortly before the Second World War began. In all, 3,249 Masters were built, the largest production run of any Miles type until the Martinet took precedence in 1942.
Design Notes
The Master was developed from the M.9 Kestrel, a private-venture demonstrator first shown at the Hendon Air Show in July 1937 and powered by a 745 hp Rolls-Royce Kestrel XVI engine. For production, Miles fitted the lower-powered Kestrel XXX, of which large surplus stocks were available, and extensively revised the airframe. The revisions brought a new cockpit canopy and a modified rear fuselage and tail, and resited the radiator beneath the wing's centre-section. Its distinguishing feature was an inverted gull wing, adopted despite higher production costs because it let the retractable undercarriage and fuel tanks be stowed within the wing. The fuselage was a plywood-skinned, oval-section semi-monocoque. Student and instructor sat in tandem, the rear seat raised 12 inches so the instructor could see over the pupil's head, and in flight the instructor could disconnect several of the student's controls. Engine availability, more than anything else, drove the variants that followed.
Operational History
Production deliveries began in late July 1939, and 900 Master I and IA aircraft were built at Woodley, among them a batch completed as single-seat M.24 Master Fighters with six 0.303-inch machine guns, an emergency fighter for the Battle of Britain that never saw combat. When Kestrel production ended, the Master was re-engined with the air-cooled Bristol Mercury XX radial of 870 hp, becoming the M.19 Master II; the prototype flew on 30 October 1939, and 1,748 were built at Woodley and South Marston. Mercury engines then ran short as well, and after Lend-Lease opened a supply of American engines the M.27 Master III was designed around the 825 hp Pratt & Whitney Twin Wasp Junior; 602 were built, all at South Marston. At Woodley, Masters came off a pioneering moving track assembly line, believed to be the first installed in a British aircraft factory. In service the Master worked mainly at (Pilot) Advanced Flying Units, where pilots were often first exposed to fighter tactics while flying it. In training fit it carried eight practice bombs and a single .303 in Vickers machine gun, for training purposes only. From 1942 the wings of all variants were clipped by three feet, reducing stress on the wings and increasing manoeuvrability. Several hundred Master IIs were converted as glider tugs, and from 1942 Masters towed General Aircraft Hotspur gliders at Glider Training Schools; the Master II also towed targets for the Central Gunnery School at Sutton Bridge. RAF aircraft were also diverted overseas: 426 went to the South African Air Force, and Masters served with the air forces of Egypt and Turkey and with United States Army Air Force units based in Britain.
Afterlife
Thousands of Masters were built, but no complete example survives today. What remains are fragments: several British aviation museums hold a few outer wings and other parts, and only a few small components are preserved. The Master's design lived on after the trainer itself in the Miles Martinet, the dedicated target tug developed from it and adopted by the RAF. The type is remembered through the pilots it trained: by 1942, advertisements were claiming that every RAF fighter pilot in training had flown the Master.