Invincible-class aircraft carrier

The Invincible class was a class of light aircraft carrier operated by the Royal Navy. Three ships were constructed, HMS Invincible, HMS Illustrious and HMS Ark Royal. The vessels were built as aviation-capable anti-submarine warfare (ASW) platforms to counter the Cold War North Atlantic Soviet submarine threat, and initially embarked Sea Harrier aircraft and Sea King HAS.1 anti-submarine helicopters. With the cancellation of CVA-01, the three ships became the replacements for Ark Royal and Eagle fleet carriers and the Centaur-class light fleet carriers, and the Royal Navy's sole class of aircraft carrier.

The three vessels have seen active service in a number of locations, including the South Atlantic during the Falklands War, the Adriatic during the Bosnian War, and in the Middle East for the 2003 Invasion of Iraq.

Invincible was decommissioned in 2005 and put in reserve in a low state of readiness. She was sold to a Turkish scrapyard in February 2011, and left Portsmouth under tow on 24 March 2011. Pursuant to the Strategic Defence and Security Review, 2010, Ark Royal followed, decommissioning on 13 March 2011. This left Illustrious as the sole remaining ship, serving as a helicopter carrier from 2011 to 2014 when it was decommissioned as well. After Invincible was decommissioned in 2005, and with the retiring of Illustrious in 2014, Royal Navy aircraft carrier usage has temporarily ceased. However, it will restart with the commissioning of the Royal Navy's new Queen Elizabeth-class super-carriers, the first of which was launched in July 2014.


Invincible-class aircraft carrier
Class Ship
Type Aircraft Carrier
Manufacturer Vickers-Armstrongs
Production Period 1973 - 1976
Origin United Kingdom - UK (Great Britain)
Country Name Origin Year
United Kingdom - UK (Great Britain) 1980
Country Name Operational Year Retirement Year
United Kingdom - UK (Great Britain) 1980 2014 View
ManufacturerName Production From Production To Quantity
Vickers-Armstrongs 1973 1976 1 View
Swan Hunter 1976 1978 2 View

The Invincible class has its origins in a sketch design for a 6,000 ton, guided-missile armed, helicopter carrying escort cruiser intended as a complement to the much larger CVA-01-class fleet aircraft carrier. The cancellation of CVA-01 in 1966 meant that the smaller cruiser would now have to provide the anti-submarine warfare (ASW) taskforce with command and control facilities. Two new designs were prepared for this requirement; a 12,500 ton cruiser with missiles forward, six Westland Sea King helicopters and a flight deck aft, somewhat similar to Vittorio Veneto of the Italian Navy and a larger 17,500 ton vessel with a "through-deck", nine Sea Kings and missiles right forward. By 1970, the "through-deck" design had advanced into a Naval Staff Requirement for an 18,750-ton Through-Deck Command Cruiser (TDCC).

In February 1963, the Hawker P.1127 VTOL (vertical take-off and landing) aircraft had landed and taken-off from the carrier Ark Royal and the subsequent Hawker-Siddeley Kestrel had undergone trials from the "Commando carrier" (an aircraft carrier operating helicopters) HMS Bulwark. It was therefore perfectly possible that the new "cruisers" could be used to operate VTOL aircraft. The new ships were called "through-deck cruisers" and not "aircraft carrier". This was in part because CVA-01's cancellation was so recent, but also because the ships were intended to serve in traditional cruiser roles of C3I and anti-submarine warfare, and were constructed like cruisers. The "aircraft carrier" name did not officially appear in association with the ships until the 1980 Defence Estimates referred to the Invincibles as such.

Economic problems in the UK in the early 1970s delayed progress on the new ships, but the design continued to evolve. The order for the first ship was given to Vickers (Shipbuilding) on 17 April 1973. By now, the design was for a 19,000 ton "CAH" (helicopter carrying heavy cruiser, styled after the US Navy hull classification symbols) with up to fourteen aircraft and a Sea Dart missile launcher on the bows.

The government decided that the carrier needed fixed-wing aircraft to defend against Soviet reconnaissance aircraft. In May 1975, it authorised the maritime version of the Hawker Siddeley Harrier, which was successfully developed into the Sea Harrier. This meant that the design was reworked again to include a small complement of these VTOL aircraft. In order to launch a heavily-laden Harrier more efficiently by STOVL (short take-off vertical landing) from the comparatively short - 170-metre (560 ft) - flight deck, a 'ski-jump' was developed. The slope was initially 7° when incorporated into Invincible and Illustrious and 12° for Ark Royal. The class also has, since 1976, a secondary role as an helicopter carrier, or LPH, in the reinforcement of NATO's Northern flank in Norway. In 1998, HMS Ocean, with a hull form based on that of the Invincible class, was commissioned specifically for this role.

Ships in Class
Name Pennant Builder Ordered Laid down Launched Commissioned Fate
Invincible R05 Vickers Armstrong, Barrow. 17 April 1973 20 July 1973 3 May 1977 11 July 1980  Broken up at Aliaga, 2011
Illustrious R06 Swan Hunter,Wallsend  14 May 1976  7 October 1976 1 December 1978 20 June 1982 Decommissioned awaiting disposal.
Ark Royal
(ex-Indomitable)
R07 Swan Hunter, Wallsend  December 1978 14 December 1978  2 June 1981 1 November 1985 Broken up at Aliaga, 2014

Falklands War

Prior to 1982, Invincible??'?s air group consisted purely of Sea King HAS.5 anti-submarine helicopters and Sea Harrier FRS.1 aircraft. Typically, nine Sea Kings, and four or five Sea Harriers were embarked. This was due to the fact that the originally envisioned mission for the ships was to provide the heart of ASW hunter-killer groups in the North Atlantic during a war against the Soviet Union. In that context, the main weapon of the carrier would not be its fighter aircraft, but its ASW helicopters. The fighters were on board to shoot down the occasional Soviet maritime patrol aircraft nosing around the ship and its escorts.

The Falklands War changed that posture, since it proved that Britain needed to retain the capability to use carrier air power in its traditional role of power projection, both over land, and against enemy fleets. The Falklands War saw Invincible, and the larger and older HMS Hermes filled to capacity with both the Sea Harrier and the Royal Air Force Harrier GR3 ground attack variant of the aircraft, along with ASW helicopters. The RAF Harriers proved to be a temporary aberration at the time. However a permanent addition to the usual air group was made due to lessons learnt during the war: the Sea King AEW2A (airborne early warning) version. Illustrious carried the first examples of the type when it was rushed south in the aftermath of the Falklands War to relieve Invincible of its guard duty around the islands.

In the aftermath of the Falklands, the typical air group was three AEW Sea Kings, nine ASW Sea Kings and eight or nine Sea Harriers. Analysis of the Sea Harrier's performance during the war lead to the requirement for an upgrade, approval for which was granted in 1984. The Sea Harrier FA2 entered service in 1993 and deployed on Invincible to Bosnia in 1994. The FA2 featured the Blue Vixen radar which is described as one of the most advanced pulse Doppler radars in the world. The FA2 carried the AIM-120 AMRAAM. The final new build Sea Harrier FA2 was delivered on 18 January 1999. Other improvements were made to the class during the 1980s and early 1990s, in particular to increase of the ski jump angle on Invincible and Illustrious to match the 12° slope of Ark Royal.

Name: Invincible-class
Builders: Swan Hunter
Vickers Limited Shipbuilding Group
Operators:  Royal Navy
Preceded by: Audacious-class fleet carrier
Centaur-class light carrier
Succeeded by: Queen Elizabeth-class
In commission: 11 July 1980 - 28 August 2014
Completed: 3
Laid up: HMS Illustrious
Scrapped: HMS Invincible
HMS Ark Royal
General characteristics
Displacement: 22,000 tonnes
Length: 209 m (686 ft)
Beam: 36 m (118 ft)
Draught: 8 m (26 ft)
Propulsion: COGAG
4 × Rolls-Royce Olympus TM3Bgas turbines
8 × Paxman Valenta diesel generators
100,000 shp (75 MW)
2 shafts
Speed: 28 kn (52 km/h; 32 mph) maximum
18 kn (33 km/h; 21 mph) cruising
Range: 7,000 nmi (13,000 km; 8,100 mi) at cruising speed
Troops: Up to 500 Marines
Crew: 650 ships company, 350 Air crew
Armament: 2 × 20 mm anti-aircraft guns
3 Phalanx/Goalkeeper close-in weapons systems
Aircraft carried: Until December 2010, 22 aircraft;
Multi Mission - Strike, ASuWand ASW
12 x Harrier GR.7/9
10 x Sea King ASaC, and Merlin HM Mk.1 helicopters
Multi Mission - Strike and ASuW
18 x Harrier GR.7/9
4 x Sea King ASaC, and Merlin HM Mk.1 helicopters
Aviation facilities: 168 m (551 ft) axial flight deck
Bow 13° ski ramp


End notes