Editing Supermarine Swift (section)

==Design and development==
===Background===
During 1945, the [[World War II|Second World War]] ended and a new [[Labour Party (UK)|Labour]] government, headed by [[Clement Attlee]], came to power in Britain.<ref name = "wood 40">Wood 1975, p. 40.</ref> The incoming government's initial stance on defence was that no major conflict would occur for at least a decade, and so there would be no need to develop or to procure any new aircraft until 1957. In accordance with that policy, aside from a small number of exceptions such as what would become the [[Hawker Sea Hawk]] for the [[Royal Navy]], the majority of [[List of Air Ministry specifications#1940.E2.80.931949|Specifications]] issued by the [[Air Ministry]] for fighter-sized aircraft during the late 1940s were restricted to research purposes.<ref name = "wood 40 43">Wood 1975, pp. 40–43.</ref> 

In part, the Swift had its origins in the experimental fighter prototypes that had been developed. Specifically, a number of Supermarine-built prototypes had been ordered under [[List of Air Ministry specifications#1940.E2.80.931949|Specification E.41/46]], which had sought the production of an experimental fighter aircraft  with a [[swept wing]]. The first of these was the ''Type 510'', which was substantially based on the straight-wing [[Supermarine Attacker]], which was procured for the [[Fleet Air Arm]]. The principal difference from the Attacker was that it had a swept wing.<ref name = "wood 46">Wood 1975, p. 46.</ref> During 1948 the Type 510 made its [[maiden flight]], a year after the first navalised prototype Attacker had flown, making it the first British aircraft to fly with both [[swept wing]]s and a swept [[tailplane]]. In trials for the Fleet Air Arm, the Type 510 was also the first swept-wing aircraft to take off from and land on an [[aircraft carrier]].

During the late 1940s, in the face of the emerging [[Cold War]], the RAF came to recognise that it would urgently require the development and procurement of fighters equipped with features such as [[swept wing]]s. That need was felt to be so pressing that it was willing to accept interim fighter aircraft while more capable fighters were being developed.<ref name = "wood 43 45">Wood 1975, pp. 43–45.</ref> In 1950, with the outbreak of the [[Korean War]], Britain's  involvement in that conflict led to a flurry of orders being placed. In particular, the RAF felt that a pair of proposed fighter aircraft from [[Hawker Aircraft]] and [[Supermarine]] were of great importance and, in the same year, ordered the proposed fighters "off the drawing board".<ref name = "wood 45 46"/> The Supermarine design was designated as the ''Type 541'', and was essentially an advanced development of the earlier Type 510 experimental aircraft.<ref name = "wood 46"/>

The initial order placed in 1950 for 100 aircraft was intended to serve as an insurance policy in the event that Hawker failed to produce a viable aircraft. .<ref name = "wood 45 46">Wood 1975, pp. 45–46.</ref> In early 1946, the Type 541 order was increased to 150 aircraft, the Air Ministry hoping that it would  enter service before the rival Hunter. However, the development of both types was protracted. 

[[File:Supermarine Swift FR.5 XD905 V-A Farnborough 10.09.55 edited-2.jpg|thumb|Swift FR.5 landing at the [[Farnborough air show]] in 1955]]

The Type 541 replaced its predecessors' [[Rolls-Royce Nene]] [[centrifugal compressor|centrifugal flow]] [[turbojet engine]] with the [[axial compressor|axial-flow]] Rolls-Royce AJ.65 turbojet, which became the [[Rolls-Royce Avon|Avon]] series. The fuselage, which had been given a cross section suitable for the Nene engine, was not redesigned for the narrower AJ.65 and Avon engines, and retained a somewhat portly appearance. The aircraft also had with a [[tricycle landing gear|tricycle undercarriage]]. Two of Type 541 prototypes were built. The first made its maiden flight on 01 August 1951<ref name="BAE_541_page">{{cite web |title=Vickers Supermarine Type 541 Swift |url=https://www.baesystems.com/en-uk/heritage/vickers-supermarine-type-541-swift |website=BAE Systems Web Site |access-date=4 December 2023}}</ref> and the second during the following year.

===Into production===
Production of the Swift had been declared to be a "super-priority" item under a policy created by [[Winston Churchill|Sir Winston Churchill]], who had regained the position of Britain's [[prime minister]] in 1951, as a means of increasing projects considered to be of vital military importance. Volume manufacturing commenced in advance of the implementation of modifications based on the results of flight experiences with the prototypes: "too much had been asked for in too little time and production aircraft were coming the production line before a major redesign could be accomplished".<ref name = "wood 46"/>

The first production variant was a fighter designated the ''Swift F Mk 1'', of which 18 were eventually built. It was powered by a single 7,500&nbsp;[[pound-force|lbf]] (33.4&nbsp;[[kilonewton|kN]])-thrust Avon 109 engine and was armed with two 30&nbsp;mm ADEN cannons. On 25 August 1952, the first flight of a production standard Swift F 1 took place. [[Peter Thorne (RAF officer)|Peter Thorne]], who had been appointed as the senior RAF test pilot for the incoming Swift in 1954, came to doubt the aircraft's suitability. Thorne and several other pilots noted the Swift had unusual handling qualities, as well as a troublesome engine.<ref>[https://www.telegraph.co.uk/news/obituaries/10974374/Air-Commodore-Peter-Thorne-obituary.html "Obituary: Air Commodore Peter Thorne."] ''The Telegraph'', 18 July 2014.</ref>

[[File:Supermarine Swift F.1 WK195 V-A BLA 13.9.53 edited-2.jpg|thumb|left|Swift.F.1 test aircraft operated by Vickers-Armstrong in 1953]]

The second variant was the ''Swift F Mk 2'', of which 16 were built. It was practically the same as the F 1, except for being fitted with two extra ADENs and the [[leading edge]] of the wing was altered from straight to a compound sweep.<ref name = "wood 46"/> However, the addition of the cannon caused problems, because the  modifications required to house the increased ammunition load led to dangerous handling characteristics, and it was also clear that more thrust was required from its engine. Numerous further modifications were required to resolve the problems.<ref name = "wood 46"/>

The third Swift variant was the ''F Mk 3'', of which 25 were built, powered by an Avon 114 engine with [[afterburner|reheat]]. It was never put into operational service with the Royal Air Force and was used as an instructional airframe. The next variant was the ''F Mk.4'', which included a variable incidence tailplane, intended to correct the handling problems that the Swift suffered from. It did fix the problem, but it was found that reheat could not be ignited at high altitude, adding to the Swift's list of problems.

The next in the line, the ''FR Mk 5'', had a longer nose to accommodate a number of cameras to allow a reconnaissance role, as well as other modifications to its structure. The FR 5 also reverted to the F 1's twin ADEN cannon armament. It first flew in [[1955 in aviation|1955]] and entered service the following year, performing reconnaissance mainly at low level, making the reheat problem at high altitude irrelevant.

Two further variants were designed. The ''PR Mk 6'' was an unarmed photo reconnaissance plane. However, its use was short-lived, due to the ever-present reheat problems. The last variant was the ''F Mk 7'', which was the first Swift model to be fitted with guided missiles, the [[Fairey Fireflash]] [[air-to-air missile]],  and was powered by a new model of the Avon. Only fourteen F 7 aircraft were built and none ever entered service with the RAF, being relegated – along with its prototype missiles – to conducting guided-missile trials.

===Proposed derivative===
{{main|Supermarine 545}}
In 1953, as a response to growing RAF interest in developing [[transonic]] aircraft to serve as a stopgap while the next generation of [[supersonic]] fighters were being developed, both Supermarine and Hawker proposed derivatives of their respective Swift and Hunter aircraft.<ref name = "wood 48 51">Wood 1975, pp. 48–51.</ref> By that time, the shortcomings of the Swift were not yet apparent, which perhaps had allowed Supermarine to gain the RAF's favour for its proposal, designated as the [[Supermarine 545|Type 545]], over the rival [[Hawker Hunter variants#Prototypes|Hawker P.1083]]. The Type 545 had been drawn up to conform with the requirements given by [[List of Air Ministry specifications#Post 1949 Specifications and Air Staff Operational Requirements.2FTargets .28OR.2FASR.2FAST.29|Specification F.105D]]. It was to have been capable of attaining [[Mach number|Mach]] 1.3. powered by an Avon engine, promising superior performance to that of the P.1083.<ref name = "wood 50 51">Wood 1975, pp. 50–51.</ref> The Type 545 bore a resemblance to the Swift, although it was a complete redesign, having an [[area rule|area-rule]]d fuselage and wing changes. In 1955, work on the project was cancelled, in part due to the considerable difficulties experienced with the Swift.<ref name = "wood 51 52">Wood 1975, pp. 51–52.</ref>