Editing Bristol Beaufighter (section)

===Origins===
[[File:Bristol Beauforts 217 Squadron in flight.jpg|thumb|upright=1.5|left|alt=Two Bristol Beauforts in flight|Bristol Beauforts in flight]]
The concept of the Beaufighter has its origins in 1938. During the [[Munich Crisis]], the Bristol Aeroplane Company recognised that the [[Royal Air Force]] (RAF) had an urgent need for a long-range fighter aircraft capable of carrying heavy payloads for maximum destruction.<ref name = "moyes 3"/> Evaluation of the [[Bristol Beaufort|Beaufort]] bomber concluded that it had great structural strength and stiffness in the wings, nacelles, [[Landing gear|undercarriage]] and tail, so that the aircraft could be readily developed further for the greater speed and manoeuvrability required by a fighter-class aircraft.<ref name = "moyes 3"/> The Bristol design team, led by [[Leslie Frise]], commenced the development of a cannon-armed fighter derivative as a private venture. The prospective aircraft had to share the same [[Jig (tool)|jigs]] as the Beaufort so that production could easily be switched from one aircraft to the other.<ref name = "moyes 3"/>

As a torpedo bomber and aerial reconnaissance aircraft, the Beaufort had a modest performance. To achieve the fighter-like performance desired for the Beaufighter, Bristol suggested that they equip the aircraft with a pair of its new [[Bristol Hercules|Hercules]] engines, capable of around 1,500&nbsp;hp, in place of the 1,000&nbsp;hp [[Bristol Taurus]] engines on the Beaufort. The Hercules was a considerably larger and more powerful engine which required larger propellers; to obtain adequate ground clearance, the engines were mounted centrally on the wing, as opposed to the underslung position on the Beaufort.<ref name = "moyes 3"/> In October 1938, the project, which received the internal name ''Type 156'', was outlined. In March 1939, the ''Type 156'' was given the name 'Beaufighter'.<ref name = "moyes 4">Moyes 1966, p. 4.</ref>

During early development, Bristol had formalised multiple configurations for the prospective aircraft, including variations such as a proposed ''Type 157'' three-seat bomber outfitted with a [[Anatomical terms of location#Dorsal and ventral|dorsal]] [[Gun turret#Aircraft|gun turret]] with a pair of cannons, and what Bristol referred to as a "sports model", with a thinner fuselage, the ''Type 158''.<ref name = "moyes 4"/> Bristol proceeded to suggest their concept for a fighter development of the Beaufort to the [[Air Ministry]]. The timing of the suggestion happened to coincide with delays in the development and production of the [[Westland Whirlwind (fighter)|Westland Whirlwind]] cannon-armed twin-engine fighter.<ref>Buttler 2004, p. 38.</ref> While there was some scepticism that the aircraft was too big for a fighter, the proposal was given a warm reception by the [[Air Staff (United Kingdom)|Air Staff]].<ref name = "moyes 3"/>

The Air Ministry produced draft [[List of Air Ministry specifications#F.11/37|Specification F.11/37]] in response to Bristol's suggestion for an "interim" aircraft, pending the proper introduction of the Whirlwind. On 16 November 1938, Bristol received formal authorisation to commence the detailed design phase of the project and to proceed with the construction of four prototypes.<ref name = "moyes 3"/> Amongst the design requirements, the aircraft had to be able to accommodate the [[Rolls-Royce Griffon]] engine as an alternative to the Hercules, and had to have maximum interchangeability between the two engines, which would feature [[Power-egg#United Kingdom|removable installations]].<ref name = "moyes 3 4"/>

Bristol began building an initial prototype by taking a partly-built Beaufort out of the production line, which sped progress; Bristol had promised series production in early 1940 on the basis of an order being placed in February 1939. Designers expected that maximum re-use of Beaufort components would speed the process, but the fuselage required more work than expected and had to be redesigned.<ref>Buttler 2004, p. 40.</ref> Perhaps in anticipation of this, the Air Ministry had requested that Bristol investigate the prospects of a "slim fuselage" configuration.<ref name = "moyes 3 4">Moyes 1966, pp. 3–4.</ref> Since the "Beaufort cannon fighter" was a conversion of an existing design, development and production was expected to proceed more quickly than with a new one. Within six months the first F.11/37 prototype, ''R2052'', had been completed.<ref name = "moyes 4"/> A total of 2,100 drawings were produced during the transition from Beaufort to the prototype Beaufighter; more than twice as many were made during later development, from the prototype to the production Beaufighter. Two weeks before the prototype's first flight, an initial production contract for 300 aircraft under Specification F.11/37 was issued by the Air Ministry, ordering the type "off the drawing board".<ref name = "moyes 4"/>