Miles Master

The M.9A Master I was based on the privately developed M.9 Kestrel trainer that was first demonstrated at the Hendon Air show in July 1937, although this aircraft never entered production. The M.9 Kestrel, powered by a single Rolls-Royce Kestrel XVI V-12 engine, capable of generating up to 745 hp (555 kW), could attain a maximum speed of 296 mph (477 km/h).Amos Aeroplane Monthly August 1980, pp. 413–414. The British Air Ministry had previously selected the de Havilland Don multi-role trainer{{Efn|training pilots, radio operators and air gunners (the Don as designed had a dorsal turret)}} to meet Specification T.6/36, which called for an advanced trainer aircraft; however, this aircraft would prove to be a failure. Still requiring an aircraft to perform the duties intended for the Don, following the prototype Master (serial N3300) the RAF placed a large order on 11 June 1938 for 500 examples of a modified version of the Kestrel (to specification 16/38), designated M.9A with the service name Master, at a cost of £2 million.{{Citation needed|date=July 2019}} This was claimed to be Britain's largest ever contract for a training aircraft at the time.

Upon receipt of this order, Miles had the prototype M.9 rebuilt into a representative prototype for the Master. Alterations included the installation of a lower-powered (715 hp (535 kW)) Kestrel XXX engine, of which there were large surplus stocks available, along with extensive revisions to the airframe, which involved the adoption of a new cockpit canopy, a modified rear fuselage and tail, along with the repositioning of the radiator from underneath the nose to the underside of the wing's centre-section. These modifications came at the cost of a significantly reduced maximum speed over the M.9; despite this, the Master was a relatively fast and manoeuvrable trainer. Miles had designed the Master to fulfil their vision of an effective trainer aircraft, being one that could match the performance of, and possess similar characteristics to, the frontline RAF monoplane fighters of the day, these being the Supermarine Spitfire and the Hawker Hurricane.[https://www.flightglobal.com/pdfarchive/view/1942/1942%20-%200292.html "Milestones...1939."] Flight, 5 February 1942. p. vi.

On 31 March 1939, the first true production Master I conducted its maiden flight.Amos Aeroplane Monthly August 1980, pp. 414–416.March 1998, p. 177. The first production examples were delivered during late July of that year.Flight, 27 July 1939. p. 77. 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.{{Citation needed|date=July 2019}}

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.[https://www.flightglobal.com/pdfarchive/view/1941/1941%20-%201430.html "The Mercurial Master."] Flight, 26 June 1941. p. 434. 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.Amos Aeroplane Monthly September 1980, p. 462.

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.{{Citation needed|date=July 2019}}

File:Miles Master.jpg

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.Amos Aeroplane Monthly September 1980, pp. 432, 464.

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.{{Citation needed|date=July 2019}}

The Miles Master was a tandem-seat low-wing cantilever monoplane, powered by a single reciprocating engine. Initial models used the Kestrel XXX engine; capable of providing up to 745 hp (555 kW), this powerplant enabled the aircraft to achieve a maximum speed of 296 mph (477 km/h), which reportedly made the Master as fast as the single-seat biplane fighters of 1935. The inverted gull wing of the Master was a major distinguishing factor of the aircraft and was adopted – despite higher production costs – for its performance benefits, permitting the stowage of both the retractable undercarriage and fuel tanks; aside from this shaping, the wing's design largely conformed with traditional approaches.Flight, 27 July 1939. pp. 77-78.[https://www.flightglobal.com/pdfarchive/view/1942/1942%20-%202212.html "Aircraft Types and their Characteristics: Miles Master III."] Flight, 22 October 1942. p. a. 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.Flight, 27 July 1939. p. 78.

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. Forward of the tandem cockpits, the nose is strengthened by a metal former that provides protection against nose-overs, a common occurrence amongst trainee pilots when flying aircraft with 'tail dragger' conventional undercarriage. The tail section had an orthodox cantilever structure, the tailplane being mounted directly on top of the fuselage; the tailplane's aerodynamics were designed to facilitate easy spin recovery. The Kestrel engine is mounted on tubular steel bearings, to facilitate engine removal for ease of maintenance through four main bolts along with the connecting leads. Further maintenance savings were made by de-rating the engine power, giving a longer interval between overhauls.

The Master was furnished with a constant-speed propeller, which was interchangeable between Rotol and de Havilland units. The Kestrel engine of early-built aircraft incorporated various auxiliary drives to power both vacuum and hydraulic pumps, along with an air compressor and a 500-watt electrical generator. Cooling for the water and oil systems was provided via a duct running underneath the fuselage. Fuel was housed in a pair of tanks, each containing up to {{Convert|36|impgal|L|abbr=on}}, accommodated within the wings; the oil tank is mounted behind a fireproof bulkhead while the water tank is mounted in front of the engine. The retractable undercarriage is operated via two separate hydraulic systems along with a hand-pump as backup; the brakes are also hydraulically-actuated.Flight, 27 July 1939. pp. 78-79.

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. The positions of the two flying crew, the student in front and the instructor behind, was staggered; the rear position was 12 inches higher to provide the instructor with greater visibility.Flight, 27 July 1939. pp. 79-80. 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. Two small panels can be opened to aid visibility while flying in poor weather conditions, sun blinds are also incorporated. Catches on either side of the sliding canopy allow for the panels to be rapidly detached, facilitating faster bailing-out during an emergency.Flight, 27 July 1939. p. 79. Other emergency equipment included a Graviner fire extinguisher mounted behind the rear seat and emergency hydraulic controls set into the floor of the cockpit.Flight, 27 July 1939. p. 80.

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.

Several hundred Master IIs were either delivered in, or subsequently converted to, a configuration that allowed their use in the glider-towing role. Such aircraft would have the lower portion of their rudder cut away to allow fitting of a towing hook. Starting in 1942, Miles Masters were extensively used as tugs for General Aircraft Hotspur gliders at various Glider Training Schools. Examples were also operated by multiple Anti-aircraft Co-operation Units of the RAF as a liaison aircraft with British Army units.{{Citation needed|date=July 2019}}

Initially, the type was mainly used for training, thus few aircraft entered squadron service. Known deployments were to No. 287 Squadron between February and August 1942, to No. 286 Squadron from November 1944 to February 1945,Jefford 2001, p. 85. and to No. 613 Squadron between August 1941 and October 1943.{{Citation needed|date=July 2019}}

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.{{Citation needed|date=July 2019}}

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.{{Citation needed|date=July 2019}}

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.{{Citation needed|date=July 2019}}

File:HKestrelA.jpg

;Miles M.9A Master

:The prototype Master (serial number N3300) was modified from the private venture M.9 Kestrel trainer prototype.{{sfn|Thetford|1979|p=410}}

;Miles M.9B Master I

:Initial production of variant of the Master, it was powered by the {{cvt|720|hp|kW}} Rolls-Royce Kestrel XXX engine. Maximum speed was {{cvt|226|mph|kn km/h}}, ceiling was {{cvt|27000|ft|m}} and maximum range was {{cvt|484|mi|nmi km}}. The Miles M.9C Master IA was an improved design with more angular windscreen and a wingspan reduced from {{cvt|39|ft|m|2}} to {{cvt|37|ft|7|in|m}} with squared wingtips, all M.9B Master Is were converted to this standard. Production totalled 900 aircraft built at Woodley.{{sfn|Gunston|1990|p=111}}{{sfn|Hancock|2008|pp=183-185}}File:Aircraft of the Royal Air Force 1939-1945- Miles M.9b-m.19 Master. H31737.jpg

;Miles M.19 Master II

:With supplies of the Kestrel engine dwindling, the Master was re-engined with the {{cvt|870|hp|kW}} Bristol Mercury XX, creating the M.19 Master II. Earlier versions had the longer wing while later versions adopted the reduced wingspan. Maximum speed was increased to {{cvt|242|mph|kn km/h}}, ceiling was {{cvt|25100|ft|m}} and maximum range was {{cvt|393|mi|nmi km}}. The Miles M.19 Master GT.II was a version modified as a glider tug, at least 133 conversions were made and 290 Master IIs were built as GT.IIs. Production totalled 1,748 aircraft built at Woodley and South Marston.{{efn|At least one and possibly nine aircraft were assembled at Doncaster Airport.}}Amos 2012, p. A182{{sfn|Gunston|1990|p=111}}{{sfn|Hancock|2008|pp=183-185}}

;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.Amos 2012, pp. 135-136File:Aircraft of the Royal Air Force 1939-1945- Miles M.9b-m.19 Master. CH6473.jpg

;Miles M.27 Master III

:To overcome shortages of Mercury engines, the {{cvt|825|hp|kW}} Pratt & Whitney R-1535 Twin Wasp Junior was fitted to a modified airframe, creating the M.27 Master III. Maximum speed was {{cvt|232|mph|kn km/h}}, ceiling was {{cvt|27300|ft|m}} and maximum range was {{cvt|320|mi|nmi km}}.Production totalled 602 aircraft, all built at South Marston.{{sfn|Gunston|1990|p=111}}{{sfn|Hancock|2008|pp=183-185}}

;Miles M.31 Master IV

:Proposed improved design to give the instructor a better field of view, none built.{{efn|The fuselage of Master IV was built but then abandoned.}}Amos 2012, pp. 95-112

{{BEL}}

• Belgian Air Force

{{flag|Egypt|1922}}

• Royal Egyptian Air Force – 26 aircraft supplied in 1944 from RAF stocksAmos 2012, pp. A226-A227Amos 2012, pp. A146 – A181

{{FRA}}

• French Air Force

{{IRL}}

• Irish Air Corps – 12 former RAF Master IIs were purchased (six in 1943 and six in 1945),Amos 2012, p. A228

{{PRT}}

• Portuguese Air Force – 4 former RAF Master IIs were delivered in 1943 and ten Master IIIs delivered from 1941.Amos 2012, pp. A224-A226

{{flag|South Africa|1928}}

• South African Air Force – 453 Master IIs were supplied to South Africa (including 25 which were lost at sea and did not arrive).Amos 2012, pp. A212-A223

{{TUR}}

• Turkish Air Force

{{UK}}

Royal Air Force operational units

{{div col}}

• No. 4 Squadron RAF
• No. 16 Squadron RAF
• No. 25 Squadron RAF
• No. 26 Squadron RAF
• No. 73 Squadron RAF
• No. 85 Squadron RAF
• No. 87 Squadron RAF
• No. 105 Squadron RAF
• No. 140 Squadron RAF
• No. 152 Squadron RAF
• No. 168 Squadron RAF
• No. 219 Squadron RAF
• No. 222 Squadron RAF
• No. 225 Squadron RAF
• No. 238 Squadron RAF
• No. 239 Squadron RAF
• No. 242 Squadron RAF
• No. 245 Squadron RAF
• No. 249 Squadron RAF
• No. 253 Squadron RAF
• No. 257 Squadron RAF
• No. 264 Squadron RAF
• No. 266 Squadron RAF
• No. 286 Squadron RAF
• No. 287 Squadron RAF
• No. 302 Polish Fighter Squadron
• No. 306 Polish Fighter Squadron
• No. 307 Polish Night Fighter Squadron
• No. 308 Polish Fighter Squadron
• No. 414 Squadron RCAF
• No. 460 Squadron RAAF
• No. 504 Squadron RAF
• No. 521 Squadron RAF
• No. 600 Squadron RAF
• No. 607 Squadron RAF
• No. 610 Squadron RAF
• No. 613 Squadron RAF
• No. 615 Squadron RAF
• No. 616 Squadron RAF

{{div col end}}

RAF training units

{{div col}}

• No. 5 Flying Training School RAF
• No. 8 Flying Training School RAF
• No. 9 Flying Training School RAF
• No. 14 Flying Training School RAF
• No. 15 Flying Training School RAF
• No. 6 Operational Training Unit RAF
• No. 41 Operational Training Unit RAF
• No. 52 Operational Training Unit RAF
• No. 53 Operational Training Unit RAF
• No. 55 Operational Training Unit RAF
• No. 56 Operational Training Unit RAF
• No. 57 Operational Training Unit RAF
• No. 58 Operational Training Unit RAF
• No. 60 Operational Training Unit RAF
• No. 61 Operational Training Unit RAF
• Central Flying School

{{div col end}}

Fleet Air Arm, Royal Navy – about 200 Master Is transferred from the Royal Air Force.

{{div col}}

• 748 Naval Air Squadron
• 759 Naval Air SquadronAmos 2012, pp. A28-A69
• 760 Naval Air Squadron
• 761 Naval Air Squadron
• 762 Naval Air Squadron
• 780 Naval Air Squadron
• 781 Naval Air Squadron
• 785 Naval Air Squadron
• 798 Naval Air Squadron

{{div col end}}

{{USA}}

• United States Army Air Forces – 44 Masters were loaned to the USAAF for communications duties and target tugs for use in the United Kingdom.Amos 2012, p. A231-A233

{{Aircraft specs

|ref=Miles Aircraft since 1925{{cite book |last=Brown |first=Don L. |title=Miles Aircraft since 1925 |publisher=Putnam & Company Ltd. |location=London |year=1970 |edition=1st |isbn=0-370-00127-3 |pages= 163–172}} and Aircraft of the Royal Air Force since 1918{{sfn|Thetford|1979|p=410}}

|prime units?=imp

|crew=2

|length ft=29

|length in=6

|length note=

|span ft=39

|span in=0

|span note=initially; {{cvt|35|ft|7|in|m}} later

|height ft=9

|height in=3

|height note=

|wing area sqft=235

|wing area note=initially; {{cvt|209|sqft|sqm}} later

|aspect ratio=6.5

|airfoil=root: NACA 23024; tip: NACA 23006

|empty weight lb=4293

|empty weight note=

|gross weight lb=5573

|gross weight note=

|max takeoff weight lb=

|max takeoff weight note=

|fuel capacity={{cvt|68|impgal|USgal l|0}} fuel; {{cvt|7|impgal|USgal l|0}} oil

|more general=

|eng1 number=1

|eng1 name=Bristol Mercury XX

|eng1 type=9-cylinder air-cooled radial piston engine

|eng1 hp=870

|eng1 note=

|prop blade number=3

|prop name=constant-speed propeller

|prop dia ft=

|prop dia in=

|prop dia note=

|max speed mph=242

|max speed note=at {{cvt|6000|ft|0}}

|cruise speed mph=

|cruise speed note=

|stall speed mph=63

|stall speed note=IAS flaps down

|never exceed speed mph=330

|never exceed speed note=IAS

|minimum control speed mph=

|minimum control speed note=

|range miles=393

|range note=

|combat range miles=

|combat range note=

|ferry range miles=

|ferry range note=

|endurance=1.8 hours

|ceiling ft=25100

|ceiling note=

• Absolute ceiling: {{cvt|26000|ft}}

|climb rate ftmin=2120

|climb rate note=

|time to altitude=

• {{cvt|15000|ft}} in 9 minutes 48 seconds
• {{cvt|20000|ft}} in 17 minutes

|sink rate note=

|lift to drag=

|wing loading lb/sqft=23.7

|wing loading note=

|disk loading lb/sqft=

|disk loading note=

|fuel consumption lb/mi=

|power/weight=

|thrust/weight=

|more performance=

• Take-off run: {{cvt|645|ft}}
• Take-off distance to {{cvt|50|ft|0}}: {{cvt|1155|ft}}
• Landing run: {{cvt|1110|ft}}
• Landing distance from {{cvt|50|ft|0}}: {{cvt|1776|ft}}

|avionics=

}}

{{Aircontent|

|related=

• Miles Kestrel
• Miles M.20
• Miles Martinet

|similar aircraft=

• North American Harvard
• Nardi FN.305
• Ikarus MM-2
• Arado Ar 96
• VL Pyry

|lists=

• List of aircraft of the Royal Air Force

|see also=

}}

{{notelist}}

{{Reflist}}

• Amos, Peter. "RAF Piston Trainer No. 10: Miles M.9A Master I". Aeroplane Monthly, August 1980, Vol. 8, No. 8. pp. 412–418.
• Amos, Peter. "RAF Piston Trainer No. 10: Miles M.19 and M.27 Master II and III". Aeroplane Monthly, September 1980, Vol. 8, No. 9. pp. 460–464.
• Amos, Peter and Don Lambert Brown. Miles Aircraft Since 1925, Volume 1. London: Putnam Aeronautical, 2000. {{ISBN|0-85177-787-2}}.
• {{cite book |last=Amos |first= Peter |title=Miles Aircraft – The Wartime Years |location= Tonbridge, Kent, England |publisher=Air-Britain Historians Ltd |date= 2012 |isbn=978-0-85130-430-4}}
• Brown, Don Lambert. Miles Aircraft Since 1925. London: Putnam & Company Ltd., 1970. {{ISBN|0-370-00127-3}}.
• {{cite book|last= Jane |first= Fred T. |title=Jane's All the World's Aircraft 1945/6 |location= London |publisher= Sampson Low Marston |date=1946 |isbn=0-7153-5019-6 |edition=1970 David & Charles reprint}}
• {{cite book |last=Gunston |first=Bill |author-link=Bill Gunston |date=1990 |title=The Illustrated Encyclopedia of Combat Aircraft of World War II |location=London |publisher=Tiger Books International |isbn=1-85501-096-8}}
• {{cite book |last=Hancock |first=Terry |date=2008 |title=Directory of Britain's Military Aircraft : Fighters, Bombers, Ground Attack, Strike and Overland Reconnaissance |location=Stroud |publisher=The History Press Ltd |isbn=978-0-7524-4525-0}}
• Jefford, C.G. RAF Squadrons, a Comprehensive Record of the Movement and Equipment of all RAF Squadrons and their Antecedents since 1912. Shrewsbury, Shropshire, UK: Airlife Publishing, 2001. {{ISBN|1-84037-141-2}}.
• {{cite book |last = Lawrence |first = Joseph |title = The Observer's Book Of Airplanes |location = London and New York |publisher = Frederick Warne & Co |year = 1945}}
• Lukins, A.H. and D.A. Russell. The Book of Miles Aircraft. Leicester, UK: The Harborough Publishing Company Ltd., 1946.
• March, Daniel M. British Warplanes of World War II. London: Aerospace Publishing, 1998. {{ISBN|1-874023-92-1}}.
• Mondey, David. The Hamlyn Concise Guide to British Aircraft of World War II. London: Chancellor Press, 1994. {{ISBN|1-85152-668-4}}.
• Temple, Julian C. Wings Over Woodley – The Story of Miles Aircraft and the Adwest Group. Bourne End, Bucks, UK: Aston Publications, 1987. {{ISBN|0-946627-12-6}}.
• {{cite book |last=Thetford |first=Owen |date=1979 |title=Aircraft of the Royal Air Force since 1918 |edition=7th |location=London |publisher=Putnam & Company |isbn=0-370-30186-2}}
• {{cite magazine |url=https://www.flightglobal.com/pdfarchive/view/1939/1939-1-%20-%200265.html |title=Trainer De Luxe |magazine= Flight |date=27 July 1939 |pages= 77–80 }}{{deadlink|date=March 2024}}

{{Commons category}}

• [http://www.austinmemories.com Austin & Longbridge Aircraft Production]
• [https://web.archive.org/web/20030501133417/http://www.constable.ca/MilesMaster.htm Miles Master M9A Trainer]
• [http://ipmsstockholm.org/magazine/2007/01/stuff_eng_hrubisko_miles_01.htm Miles Master as model on IPMS Stockholm pages]

{{Miles aircraft}}

Category:1930s British military trainer aircraft

Master

Category:Glider tugs

Category:Single-engined tractor aircraft

Category:Low-wing aircraft

Category:Aircraft first flown in 1939

Category:Inverted gull-wing aircraft

Category:Aircraft with retractable conventional landing gear

Category:Single-engined piston aircraft