During the Battle of Britain, the Royal Air Force was faced with a potential shortage of fighters. To meet the Luftwaffe threat, the Air Ministry commissioned Miles to design the M.20, to specification F.19/40; nine weeks and two days later the first prototype flew.[1]
To reduce production times the M.20 was of an all-wood construction, used many parts from the earlier Miles Master trainer, lacked hydraulics, and had spatted fixed landing gear. The engine was a complete Rolls-Royce Merlin XX "power egg", and was identical to those used on the Avro Lancaster and some Bristol Beaufighter marks. The design also featured a bubble canopy for improved pilot visibility, one of the first fighters to do so.[2]
Testing and evaluation[edit source | editbeta]
The first prototype, with the B-class serial U-9 first flew on 15 September 1940,[3] and was tested at the A & AEE under the military serial number AX834 against Specification F.19/40. Armed with the same eight .303 Browning machine guns as the Hawker Hurricane, the M.20 prototype was faster than the Hurricane and slower than the Spitfire types then in production, but carried more ammunition and had greater range than either. As the Luftwaffe was defeated over Britain, the need for the M.20 vanished and the design was abandoned without entering production. The first prototype was later scrapped at Woodley.
A second prototype, U-0228 and later serialed as DR616, was built to Specification N.1/41 for a Fleet Air Arm shipboard fighter, equipped with an arrestor hook and catapult launch points. It first flew on 8 April 1941.[4] This variant was also fitted with jettisonable undercarriage so it could be used from catapults on Catapult Aircraft Merchantmen, however these ships had no flight decks so the aircraft had to be ditched into the sea after just one mission. Old Hawker Hurricanes took on this role, relegating the M.20 as superfluous and consequently leading to the scrapping of the shipboard variant.
Specifications (M.20/4)[edit source | editbeta]
Data from The British Fighter since 1912[5]
General characteristics
Crew: One pilot
Length: 30 ft 8 in (9.35 m)
Wingspan: 34 ft 7 in (10.54 m)
Height: 12 ft 6 in (3.81 m)
Wing area: 234 ft² (21.74 m²)
Empty weight: 5,908 lb (2,685 kg)
Max. takeoff weight: 8,000 lb (3,629 kg)
Powerplant: 1 × Rolls-Royce Merlin XX V12 inline engine, 1,260 hp (940 kW)
Performance
Maximum speed: 333 mph (290 knots, 536 km/h)
Range: 920 mi (800 nmi, 1,481 km)
Service ceiling: 32,800 ft (10,000 m)
Climb to 20,000 ft (6,100 m): 9 min 36 s
Armament
Guns: 8× .303 inch Browning machine guns
