Miles M.20
M.20 | |
---|---|
Second prototype of the Miles M.20 | |
Role | Lightweight fighter |
Manufacturer | Miles Aircraft |
Designer | Walter G. Capley |
First flight | 15 September 1940 |
Primary user | Royal Air Force (trials only) |
Number built | 2 prototypes |
Developed from | Miles Master |
The Miles M.20 was a Second World War British fighter developed by Miles Aircraft in 1940. It was designed as a simple and quick-to-build "emergency fighter" alternative to the Royal Air Force's Spitfires and Hurricanes should their production become disrupted by bombing expected in the anticipated German invasion of the United Kingdom. Due to the subsequent shifting of the German bombing effort after the Battle of Britain towards British cities in what became known as The Blitz, together with the dispersal of British fighter manufacturing, the Luftwaffe's bombing of the original Spitfire and Hurricane factories did not seriously affect production, and so the M.20 proved unnecessary and the design was not pursued.
Design and development
At the outbreak of the
To reduce production time the M.20 employed all-wood construction and used many parts from the earlier Miles Master trainer, lacked hydraulics, and had spatted fixed landing gear. The fixed undercarriage freed space and payload sufficient for twelve .303 Browning machine guns and 5000 rounds, and 154 Imperial gallons (700 litres) of fuel (double the range and ammunition capacity of the Hawker Hurricane and Supermarine Spitfire).[3] The M.20 was fitted with a bubble canopy for improved 360-degree vision.
In line with a design philosophy emphasising simplicity, speed and re-using available components, the engine was a Rolls-Royce Merlin XX "power egg" identical to those used on Merlin-powered Avro Lancasters and Bristol Beaufighters. This conferred flight performance that fell between those of Britain's two frontline fighters.
Testing and evaluation
The first prototype first flew on 15 September 1940,
A second prototype, U-0228 (later DR616) was built to
Test pilot Eric Brown flew this aircraft in January 1942. He reported that "although surprisingly nippy in performance, could not match the Martlet, Hurricane, or Spitfire in manoeuvrability".[6] It lacked also the excellent deck landing characteristics of the Martlet.
Accounts compare the M.20's performance with that of Battle of Britain aircraft. The M.20 (345 mph (555 km/h) at 20,400 ft (6,200 m)) was powered by a Rolls-Royce Merlin XX with a two‑speed supercharger. A Hurricane IIB with the same engine did 342 mph (550 km/h) at 22,000 ft (6,700 m). A Spitfire Mk.VC, powered by a similar Merlin 45 did 374 mph (602 km/h) at 13,000 ft (4,000 m). The Spitfire was armed with two 20 mm (0.79 in) cannons and four .303 in (7.7 mm) machine guns. The other two aircraft were armed with eight .303 in (7.7 mm) machine guns.[7]
Specifications (M.20/4)
Data from The British Fighter since 1912,[8] Miles Aircraft since 1925[9]
General characteristics
- Crew: One
- Length: 30 ft 1 in (9.17 m)
- Wingspan: 34 ft 7 in (10.54 m)
- Height: 12 ft 6 in (3.81 m)
- Wing area: 234 sq ft (21.7 m2)
- Airfoil: root: NACA 23021; tip: NACA 23009[10]
- Empty weight: 5,870 lb (2,663 kg)
- Max takeoff weight: 7,758 lb (3,519 kg)
- Fuel capacity: 154 imp gal (185 US gal; 700 L) fuel ; 8.5 imp gal (10 US gal; 39 L)
- Powerplant: 1 × Rolls-Royce Merlin XXV-12 liquid-cooled piston engine, 1,260 hp (940 kW) at 3,000 rpm
- Propellers: 3-bladed Rotolconstant-speed propeller
Performance
- Maximum speed: 333 mph (536 km/h, 289 kn) at 20,600 ft (6,300 m) combat load
- 350 mph (560 km/h) clean at 20,600 ft (6,300 m)
- Stall speed: 80 mph (130 km/h, 70 kn) flaps down
- 101 mph (163 km/h) flaps up
- Range: 550 mi (890 km, 480 nmi) / 2 hour duration - normal
- 870 mi (756 nmi; 1,400 km) / 5 hours 12 minutes duration - absolute maximum
- Endurance: 5 hours 12 minutes at 9,000 ft (2,743 m)
- Service ceiling: 31,400 ft (9,600 m)
- Absolute ceiling: 35,500 ft (10,800 m)
- Rate of climb: 3,200 ft/min (16 m/s)
- Time to altitude: 20,000 ft (6,100 m) in 9 minutes 36 seconds
- Wing loading: 33.2 lb/sq ft (162 kg/m2)
- Take-off run: 810 ft (250 m) with 30° flap
- Take-off distance to 50 ft (15 m): 1,350 ft (410 m) with 30° flap
Armament
- Guns: 8 × .303 in (7.7 mm) Browning machine guns
See also
Related development
Aircraft of comparable role, configuration, and era
- Bell XP-77
- Caudron C.714
- Douglas XP-48
- Martin-Baker M.B.2
- Tucker XP-57
Related lists
References
Citations
- ^ a b Brown Aeroplane Monthly April 1976, pp. 207–208.
- ^ Bridgeman 1946, p. 133.
- ISBN 1-85152-668-4.
- ^ Jarrett 1992, p.55.
- ^ Jarrett 1992, p. 57.
- ^ Wings on my Sleeve, Eric Brown, Pg43
- ^ War Planes of the Second World War, Fighters, Volume 2, William Green, 1961
- ^ Mason 1992, pp. 292–293.
- ISBN 0-370-00127-3.
- ^ Lednicer, David. "The Incomplete Guide to Airfoil Usage". m-selig.ae.illinois.edu. Retrieved 16 April 2019.
Bibliography
- Bridgeman, Leonard. "The Miles M.20." Jane's Fighting Aircraft of World War II. London: Studio, 1946. ISBN 1-85170-493-0.
- Brown, Don. "Last-ditch defender". Aeroplane Monthly, Vol. 4, No. 4, April 1976, pp. 207–211.
- Green, William. Warplanes of the Second World War, Fighters, Vol. 2. London: Macdonald, 1961.
- Jarrett, Philip. "Nothing Ventured..." Part 21. Aeroplane Monthly, Volume 20 No. 1, Issue 225, January 1992, pp. 54–60. London: IPC. ISSN 0143-7240.
- Mason, Francis K. The British Fighter since 1912. Annapolis, Maryland: Naval Institute Press, 1992. ISBN 1-55750-082-7.
- Mondey, David. The Hamlyn Concise Guide to British Aircraft of World War II. London: Chancellor Press, 2002. ISBN 1-85152-668-4.
- Swanborough, Gordon. British Aircraft at War, 1939–1945. East Sussex, UK: HPC Publishing, 1997. ISBN 0-9531421-0-8.