The Fairey Gannet is a carrier-borne aircraft that was designed and produced by the British aircraft manufacturer the Fairey Aviation Company. It was developed for the Royal Navy, being the first fixed-wing aircraft to combine both the search and strike portions of anti-submarine warfare (ASW) operations to be operated by the Fleet Air Arm (FAA).
The Gannet was originally developed to meet a Second World War era requirement for a dual-role ASW and strike to equip the FAA.Taylor 1974, pp. 356–357. It was a mid-wing monoplane with a tricycle undercarriage and a crew of three, with a double turboprop engine driving two counter-rotating propellers. On 19 September 1949, the prototype Gannet performed its maiden flight. Four years later, it was brought into regular service with the FAA. The service would use the type from the majority of its aircraft carriers throughout the Cold War. Various export customers were also secured for the Gannet, including the Royal Australian Navy, the German Navy, and the Indonesian Navy, most of these operating the aircraft exclusively from land bases.
During the 1960s, the Royal Navy transitioned to using helicopters, such as the Westland Whirlwind HAS.7, for ASW operations. Accordingly, several Gannets were adapted to perform alternative operations, such as an airborne electronic countermeasures platform and carrier onboard delivery aircraft. Perhaps the most extensive variant of the type was the Gannet AEW.3, which was developed as a carrier-based airborne early warning platform and was operated exclusively by the FAA. The service disposed of its Gannets on 15 December 1978, roughly aligning with the withdrawal of the last of the Royal Navy's large fleet carriers.
Development Background According to the aviation historian H. A. Taylor, the origins of what would become the Gannet can be traced back to 1935, when the Fairey Aviation Company started development of the unsuccessful Fairey Prince that used an unusual twin-engine arrangement.Taylor 1969, p. 356. Formal design work on the Gannet commenced in response to the issuing of requirement GR.17/45 in 1945, under which the Admiralty sought a new twin-seat aircraft capable of performing both anti-submarine warfare (ASW) and strike missions. Two rival aircraft manufacturers, Fairey and Blackburn Aircraft, opted to produce responses. Fairey's submission was known as the Type Q or Fairey 17 (these designations being sources from the naming of the requirement), while Blackburn's was the Blackburn B-54 / B-88.Taylor 1969, p. 357.
For 18 months, Fairey investigated the use of a single Rolls-Royce Tweed turboprop engine to power their proposed aircraft, however, this option was discontinued to concentrate on other efforts.Williams 1989, p. 94. Instead, Fairey approached the engine manufacturer Armstrong Siddeley to develop a new engine based on the existing Armstrong Siddeley Mamba turboprop: the Double Mamba (otherwise known as the "Twin Mamba")."British Fighter Aircraft" in Chambers's Encyclopædia. London: George Newnes, 1961, Vol. 1, Plate III. This engine basically comprised a pair of Mamba engines that were mounted side-by-side and sharing a common gearbox. The proposal was enthusiastically accepted and formal design work on the engine started in December 1945.Taylor 1969, pp. 356-357.
The acceptance of this proposal enabled Fairey to develop a rather atypical propulsion arrangement for their proposed aircraft, which was normally only possible for a single engined aircraft. Via the use of a pair of coaxial contra-rotating propellers fitted on the nose of the aircraft, various advantages were presented over conventional twin-engine counterparts; one engine could be shut down and its propellers feathered without producing asymmetry and therefore control difficulties. Shutting down one of the two engines in flight would reduce fuel consumption and extend the aircraft's range.Taylor 1969, pp. 357-358.
On 12 August 1946, Fairey was awarded an initial contract to produce two prototypes; Blackburn also received a competing contract to build its own prototypes. One reason for the ordering of multiple prototypes was so that alternative engines, such as the Napier Nomad, could be test flown, although some of these alternatives would never actually be fitted. Another reason was the relatively radical engine arrangement and the high proportion of original design features incorporated into the aircraft.Taylor 1969, pp. 357-359.
Into flight On 19 September 1949, the prototype performed its maiden flight from Aldermaston outside Reading, flown by R. G. Slate; this milestone occurred ten months ahead of Blackburn's competing prototype. While some elements of the prototype proved relatively trouble-free, such as the Double Mamba engine, several early test flights had been troubled by flight control difficulties. These issues, such as sharp trim changes, did not delay the next stage of testing, which commenced in November of that year at Fairey's White Waltham facility. On 25 November 1949, the prototype crash-landed during an unstable landing, leading to three months of repairs.Taylor 1969, pp. 358-359.
On 1 March 1950, flight testing resumed with the repaired prototype.Taylor 1969, pp. 359. By this point, several of the handling issues had been appropriately remedied along with several other faults, yet difficulties with holding the nosewheel up during landings remained. Two months later, sufficient progress had been made to proceed with a formal assessment by naval test pilots at RAF Boscombe Down as well as to begun preliminary carrier trials.Taylor 1969, pp. 359, 361. On 19 June 1950, the prototype conducted the first deck landing by a turboprop aircraft on , piloted by Lieutenant Commander G. Callingham.
On 6 July 1950, the second prototype took to the skies, joining the flight test shortly thereafter. As a result of changes to the operational requirements, this aircraft featured numerous changes from the first prototype, such as a third canopy for an additional crew member and an extended bomb bay. To accommodate the latter, the radome had to be repositioned rearwards; the first prototype was modified to reflect these changes for the aerodynamic trials.
In May 1952, the first prototype returned to Boscombe Down to conduct deck landing assessments and trials, having been configured to represent a production-standard aircraft by this point. Changes included the repositioning of the main landing legs rearwards by 12 inches. Following a full series of handling trials, further carrier trials were performed aboard . On 13 March 1951, Fairey received an initial order for 100 Gannet AS.1s from the British Government; this had been placed as a 'super-priority' on account of the Korean War. In 1953, quantity production of the type commenced.Taylor 1969, p. 363.
On 9 June 1953, the first production Gannet performed its initial flight from RAF Northolt and was put to work in the latter stages of the flight test programme. One serious flaw encountered during the later stage of trials was instances of compressor stalls; the type was grounded for two months while the propeller control system was modified accordingly.Taylor 1969, p. 365. One early production aircraft appeared at the 1953 Society of British Aerospace Companies (SBAC) display at Farnborough. On 5 April 1954, four Gannets were formally handed over to the FAA at RNAS Ford.Taylor 1969, p. 364.
Further development The development of several variants of the Gannet started relatively early. On 16 August 1954, the first Gannet T.2, a dedicated trainer variant made its initial flight; it was furnished with dual controls in the forward cockpits, with a retractable periscope for the second cockpit, while the radar apparatus and scanner equipment were deleted.Taylor 1969, pp. 365-366. Production of the Gannet was shared between Fairey's factories at Hayes, Middlesex and Heaton Chapel, Stockport / Manchester (Ringway) Airport. During 1954, production commenced at Heaton Chapel, the first aircraft from this production line flew on 5 October of that year. That same month, tropical trials were conducted in Khartoum.Taylor 1969, p. 366.
During the late 1950s, an improved ASW model, the Gannet AS.4, and its T.5 trainer equivalent were developed. The improvements included the fitting of an up-rated Double Mamba engine. Several were refurbished with new electronics and radar; these were re-designated Gannet AS.6.Taylor 1969, p. 370.
During 1958, the Gannet was selected to replace the Douglas Skyraider in the airborne early warning and control (AEW) role.Taylor 1969, p. 372. In order to accommodate the systems required for this new mission, the Gannet underwent a significant redesign that saw a new version of the Double Mamba installed, a new radome mounted under the aircraft, the tailfin increased in area, the undercarriage lengthened and the weapons bay removed. A total of 44 aircraft (plus a single prototype) of the AEW.3 version were produced.Taylor 1969, pp. 372, 375.
Design
The Fairey Gannet is a carrier-borne turboprop-powered aircraft. It was typically operated by a crew of three, a pilot and two aerial observers. The pilot was seated directly above the aircraft's Double Mamba engine and behind the gearbox and contrarotating propellers in a position that conferred a favourable view over the nose for carrier operations. The first observer was seated underneath a separate canopy that was directly aft of the pilot's position. On the production aircraft, a second observer was also present in their own cockpit that was located over the wing trailing edge. This addition disturbed the airflow over the horizontal stabiliser, necessitating the addition of small finlets on either side.Williams 1989, p. 95.
The wing of the Gannet folded in two places, forming a distinctive Z-shape on each side, to minimise its space requirements while being stowed onboard aircraft carriers. The first fold was upwards, at about a third of the wing span where the inboard anhedral (down-sweep) changed to the outboard dihedral (up-sweep) of the wing (described as an inverted gull wing). The second wing fold was downward, at about two-thirds of the wing span. The length of the nosewheel shock absorber caused the Gannet to have a distinctive nose-high attitude, which was a common characteristic of carrier aircraft of the era.
The Gannet had a sizable internal bomb bay within the fuselage; it was the first British aircraft in FAA service to be capable of storing all its munitions (other than rockets) within an internal bomb bay. Such munitions could include depth charges, sonobuoys, homing torpedoes, bombs, markers, and mines. Hard points beneath the outer wings could carry up to 16 Mk.8 or 24 Mk.5 rocket projectiles; other equipment included 100 gallon external fuel tanks. The primary search apparatus was the air-to-surface-vessel (ASV) radar, which made use of a retractable radome positioned underneath the rear fuselage just to the aft of the bomb bay.Taylor 1969, p. 358.