Miles Master

{|Infobox aircraft type
|type = Advanced trainer
|manufacturer = Phillips and Powis Aircraft Ltd
|designer = F. G. Miles
|first flight = 31 March 1939
|introduced = 1939
|retired =
|status = Out of production, retired
|primary user = Royal Air Force
|more users = Egypt South African Air Force Turkey
|number built = 3,249

On 31 March 1939, the first true production Master I conducted its maiden flight. The first production examples were delivered during late July of that year. The Master had entered RAF service just prior to the start of the Second World War. Eventually, 900 Mk. I and Mk. IA Masters were constructed. This total included 26 built as the M.24 Master Fighter which were modified to a single seat configuration, and armed with six .303 in machine guns for use as an emergency fighter; this model never saw combat use. When production of the Kestrel engine ceased, a new variant of the Master was designed that used an air cooled Bristol Mercury XX radial engine, capable of producing 870 hp (650 kW), instead. Thus configured, on 30 October 1939, the first M.19 Master II prototype made its first flight; 1,748 aircraft were eventually built. After the Lend Lease programme provided a supply of engines from the United States to Britain, a third variant of the Master, designated M.27 Master III, was designed, which was powered by the American built Pratt & Whitney Twin Wasp Junior, a two row radial engine that could generate 825 hp (615 kW). A total of 602 Master IIIs were constructed. In a typical trainer configuration, the Master was equipped to carry eight practice bombs, plus a single .303 in Vickers machine gun that was mounted in the front fuselage. During 1942, it was decided to have the wings of all variants clipped by three feet (c. one metre); this modification reduced the stress imposed upon the wings while also increasing the aircraft's manoeuvrability.

A total of 3,249 Masters were built by Phillips and Powis Aircraft Limited (as Miles was known until 1943) at Woodley, Berkshire; South Marston, near Swindon, Wiltshire; and Doncaster. This was the largest number produced of any Miles aircraft type prior to production of the newer Miles Martinet taking precedence during 1942. The mass production of this aeroplane at Woodley required a major expansion of the original Phillips & Powis factory, which was officially opened on 27 January 1939 by the Secretary of State for Air, Sir Kingsley Wood. This facility was outfitted with a pioneering moving track assembly line, which is believed to be the first such facility in a British aircraft factory. A similar facility was also installed in the company's shadow factory at South Marston by the end of 1940.

The Miles Master was a tandem seat low wing cantilever monoplane, powered by a single reciprocating engine. It featured hydraulically actuated split flaps along its trailing edge, their position being indicated electronically on the cockpit's instrumentation panel. The wing's centre section also accommodated a single machine gun. While the Master had incorporated relatively advanced aerodynamic characteristics (intended to mimic frontline fighters) for a contemporary trainer aircraft, it used a conventional structure, comprising an oval section fuselage covered by a plywood skin, featuring a semi monocoque approach. The cockpit of the Master was designed with considerable attention to best facilitate its use as a trainer aircraft, including for ease of use and comfort. Mid flight, an instructor could disconnect several of the student pilot's controls, such as the brakes, using various cut outs. The forward windscreen is composed of moulded Perspex and furnished with a reflector type gun sight, providing an optically perfect view of a target. Other emergency equipment included a Graviner fire extinguisher mounted behind the rear seat and emergency hydraulic controls set into the floor of the cockpit.

Typical service use of the Master primarily revolved around (Pilot) Advanced Flying Units, where they were used for training aircrew in preparation for service with frontline squadrons. Amongst other parts of the training syllabus, pilots would often be first exposed to fighter tactics while flying the aircraft. By 1942, advertisements claimed that the Master was being flown by every RAF fighter pilot in training. and to No. 613 Squadron between August 1941 and October 1943. The Master II was also used for target tug purposes at the Central Gunnery School whilst the School was based at RAF Sutton Bridge from April 1942 to March 1944. In this role, they pulled the drogue targets required for aerial gunnery training by pupils at the Pilot Gunnery Instructors' Training Wing. The Miles Martinet, a derivative of the Master, was a developed specifically to be a target tug and would see widespread use in this capacity. RAF stocks were frequently diverted to support several of the air services of the Allies and other non hostile nations. Such diversions included 426 aircraft to the South African Air Force, 52 to the Fleet Air Arm, nine to the United States Army Air Force units based in Britain, 23 to the Royal Egyptian Air Force, 23 to Turkish Air Force, two to Portuguese Air Force, and fourteen to the Irish Air Corps. Despite having been produced in the thousands, there are no known surviving aircraft of the type today, although a few outer wings and other parts are held by several aviation museums in Britain.

Miles M.9A Master
The prototype Master (serial number N3300) was modified from the private venture M.9 Kestrel trainer prototype. Miles M.24 Master Fighter
Stop gap fighter version of Master I with rear seat removed and six 0.303 Browning machine guns in the wings. 25 conversions of Master Is on the production line. Miles M.27 Master III
To overcome shortages of Mercury engines, the Pratt & Whitney R 1535 Twin Wasp Junior was fitted to a modified airframe, creating the M.27 Master III. Maximum speed was , ceiling was 8321.04 m and maximum range was Production totalled 602 aircraft, all built at South Marston.