The UK's Invincible class aircraft carriers still have a decade in service ahead and the Royal Navy is determined to get the best out of them

By the end of 2015 - assuming current programme and funding profiles hold firm - the UK Royal Navy (RN) should be operating two new Future Aircraft Carriers (CVFs) of 60,000t displacement each equipped with an air wing based around the new Joint Combat Aircraft (JCA) - the Lockheed Martin F-35B Joint Strike Fighter.

But for the next decade, the service must strive to get the best out of its three existing Invincible class carriers (CVSs): HMS Invincible, HMS Illustrious and HMS Ark Royal. While somewhat constrained in size and configuration, these "legacy assets" are required to carry UK carrier air power forward into the CVF era - and in doing so realise the maximum potential of aviation packages drawing on carrier-compatible aircraft from across the RN, the Royal Air Force (RAF) and the British Army.

The increasingly routine embarkation and operation of aircraft from outside the Fleet Air Arm illustrates a culture shift that promotes the concept of "maritime" rather than purely "naval" aviation.

"We previously thought very much in terms of naval aviation," says Rear Adm Adrian Johns, dual-hatted as Assistant Chief of Naval Staff and Rear Admiral Fleet Air Arm. "This was an activity predominantly undertaken by people in a dark blue naval uniform, using aircraft with 'Royal Navy' stencilled on their side.

"Maritime aviation is a wider joint warfighting concept. It is aviation from the sea delivered by all three services, and recognises the carrier as a joint defence asset, not just a naval one."

The RN has two 19,000t CVSs in commission at any given time. One is maintained as a high-readiness carrier at R2 state (ready for sea at two days' notice) with the other held at R6 (60 days' notice). The third vessel remains in refit or reserve.

Invincible is currently at high readiness. It took part in Exercise Joint Winter during March and in early May was deployed to participate in Exercise Rapid Alliance off the US east coast. Ark Royal, meanwhile, entered extended readiness in April, ahead of a docking period in 2006. Illustrious, currently undergoing a major refit at Rosyth, is due to begin work-up early next year to re-enter the operational cycle in mid-2005.

Originally built as the centrepiece of NATO's anti-submarine strike force, carrying helicopters plus a small number of British Aerospace Sea Harriers for air defence, the Invincible class vessels have been recast as power projection assets in the post-Cold War era. This was first demonstrated by three years of continuous carrier task group operations off the former Yugoslavia from 1993 to 1996, then a series of high-profile deployments east of Suez.

Since 1997 - before the RN/RAF Joint Force Harrier (JFH) was established in 2000 - the Sea Harrier has been routinely joined at sea by RAF BAE Systems Harrier GR7 ground-attack aircraft. The early retirement of the Sea Harrier FA2 will see 800 and 801 Naval Air Squadrons re-equip with the Harrier GR7/9 as part of a JFH migration that will see both "light blue" and "dark blue" squadrons operating the Harrier GR9/9A by mid-2007.

Designed to build on the capabilities of the current GR7, the Harrier GR9 upgrade introduces an updated weapon system based on a 1760 standard stores management system, new open-system mission computer and associated high-order language operational flight program to enable the aircraft to employ precision-guided weapons. Also included in the upgrade is the integration of the Successor identification friend or foe system, a tactical datalink, a new INS/GPS that can provide the weapons with navigation data via the 1760 databus, a ground proximity warning system and improvements to display software.

Improved thrust

Seventy aircraft will receive the GR9 upgrade, which is being led by BAE Systems Military Air Solutions & Support. Of these, 30 aircraft that are separately receiving the uprated Rolls-Royce Pegasus 107 engine will be designated Harrier GR9As. Delivering 3,000lb (13.35kN) more thrust than the 105 it replaces, the new powerplant significantly improves vertical recovery margins, which is an asset during carrier operations in high ambient temperatures.

The first of 20 Harrier GR7s upgraded to an interim GR7A standard with the Pegasus 107 were delivered last November, and seven subsequently completed a first short embarkation - Exercise Hairy Funnel - aboard HMS Invincible the same month.

Last year also saw work to revise the safety case for Harrier GR7/GR9 operations aboard the CVS, specifically addressing the different behaviour and handling characteristics of the type compared with the Sea Harrier. BMT Defence Services was contracted to assess the safety risks at the ship/air interface and submitted its provisional report in May 2003, highlighting a number of safety concerns that could compromise the full range of air operations from the CVS. Remedial action was undertaken based on the ship aviation safety report and a full letter of release was signed off last October endorsing the safety case required for full operation of JFH.

Although there is a clear focus on using the CVSs in a strike role, the Invincible class ships also maintain a capability to operate in a secondary amphibious helicopter carrier (LPH) role. The RN has its own dedicated LPH, HMS Ocean, but one CVS must remain at 30 days' notice to re-role as an LPH. Last year saw Ark Royal rapidly reconfigured into the LPH "swing" role and deployed to the Gulf as part of Operation Telic - the UK's contribution to US-led military operations in Iraq.

Reconfiguring Ark Royal as an LPH entailed offloading and reloading ammunition and then undertaking intensive training to get the ship conversant with operating an all-rotary-wing Tailored Air Group (TAG). This comprised five Joint Helicopter Command Boeing Chinook HC2s from the RAF's No 18(B) Squadron and four Westland Sea King ASaC7 airborne surveillance and control aircraft from 849 Naval Air Squadron's A Flight.

Chinook operations presented particular challenges because of the aircraft's size, weight on deck, lack of blade fold, and the absence of telebrief and I-band transponder facilities. The solution was to go back to basics, with precise timing of flightdeck movements, strict adherence to drill and pragmatic flightdeck spotting.

Air group evolution

"Over the past few years it has been good to see the CVS evolving from being a platform optimised for sea control towards a flexible joint power projection asset able to deploy joint air power independent of large runways abroad," says Cdre Adrian Nance, commanding officer of Ark Royal until last April. "As part of that flexibility, we have dispensed with the concept of a rigid carrier air group and now have a tailored air group that is optimised for each mission."

The TAG has been likened to a golf bag, assembled "club by club" to suit a specific operation or campaign. Here the "clubs" include the Harrier GR7 ground-attack aircraft, the upgraded GR9 to enter service from 2006, the Sea Harrier FA2 fighter until its retirement in March 2006, the Sea King ASaC7 airborne surveillance and control helicopter, the EH Industries EH101 Merlin HM1 maritime helicopter, the Sea King HC4 medium support helicopter, the Chinook HC2 support helicopter and, soon, the army's Apache AH1 attack helicopter.

"This is a fundamental change to CVS aviation operations," says Nance. "It requires a more flexible approach to our thinking and procedures to exploit the unique operational and logistics requirements of mixed TAGs."

But size is a permanent constraint for the CVS, and a TAG of 22-24 fixed- and rotary-wing aircraft is the most that can be accommodated with a sensible operating cycle. Competition for scarce engineering space also restricts the number of different aircraft types that can be supported concurrently. Only when the JFH has rationalised to a single type will there be room again for Merlin and its logistic support to be embarked. Deck estate is also limited, and it is a legacy of the Invincible class's origins as a helicopter-only platform that fixed-wing aircraft must use virtually the whole flight deck to launch.

Conscious of the need to adapt the CVS for power projection missions, either as a fixed-wing heavy-strike platform or an all-rotary-wing LPH, the RN has tried to configure its carriers better for the embarked TAG. For example, it has modified air engineering sustainability, magazines and aircrew mission planning and preparation areas to be flexible enough to meet the needs of different air groups. The bulky Sea Dart missile system fitted forward has been removed and the flight deck area extended to provide for one extra helicopter spot and additional deck parking.

In late 2006 Invincible will be retired from the front-line fleet and laid up in a state of preservation until 2010, leaving Illustrious and Ark Royal as the two running carriers until their programmed out-of-service dates of 2012 and 2013, respectively. Part of Illustrious's current refit involves installing 300 additional bunk spaces to improve its capability in the secondary LPH role. In effect, the ship will become a "flex-carrier" better able to fill in as a high-readiness LPH when Ocean is in major maintenance.

Getting the most

Work on future programming and employment of the CVS is being managed by Capt David James, Deputy Assistant Chief of Staff (Aircraft Carriers) on the staff of the Commander-in-Chief Fleet. In an earlier appointment as a desk officer in the Ministry of Defence, James took an embryonic CVF programme through the UK's Strategic Defence Review. His job now is "to get the most out of the UK's existing carrier aviation assets, and to prepare the fleet to get the most out of CVF".

A concept of use for the CVS written by James was endorsed at one-star level in late April. "The primary role of the high-readiness carrier is to support the deployment of offensive air power through Joint Force Harrier," he says. "With the retirement of the Sea Harrier in 2006 and the attendant migration to the Harrier GR9/GR9A, we want to further develop the capability of the carriers in the strike role.

"But to support high sortie generation rate offensive air missions from the CVS requires investment to address specific shortfalls in areas such as weapon numbers and supply, recovery aids, mission support and NEC [network-enabled capability]. Schemes of complement and training must be tailored accordingly. Also, as we move towards the strike carrier concept, it is becoming increasingly clear that this will place limits on the ability to use the CVS in the LPH or command and control roles."

A strike-heavy TAG could comprise up to 18 Harrier GR7/9s. However, it is not just a case of bringing the aircraft, aircrew and engineering support aboard - the CVS also has to accommodate RAF-supplied mission planning and reconnaissance imagery processing facilities if it is to fully exploit its air group's offensive potential.

"HAMPA [Harrier advanced mission planning aid] and SKAMPA [Sea King advanced mission planning Aid] are applications to support the mission planning for the Harrier and Sea King ASaC7," says James. "Illustrious will have the local area network and some hardware installed in the aviation planning/briefing spaces when it comes out of refit. These same modifications will go into Ark Royal during its next docking period.

"Both systems work from a common core, with most of the information accessed via the RAFCCIS [RAF command, control and information system]. This, in turn, must be supported through the navy's own command support system."

Manpower structures

A related work strand now under way is a review of CVS manpower structures and individual training to better support the aircrew in the use of mission planning equipment, and to better interface with other air command and control organisations, principally the Joint Forces Air Component Command and the Combined Air Operations Centre. The review should be complete by mid-year to enable personnel to undergo training before joining Illustrious.

All CVSs are "fitted for but not with" the Ground Imagery Exploitation System (GIES) to support operations when Harriers embark carrying the Thales-Vinten Joint Reconnaissance Pod, with GIES images disseminated to all interested parties through RAFCCIS. "When funds allow, we have an aspiration for a permanent GIES groundstation fit," says James, "but we would still expect an additional carry-on system to provide redundancy."

Ordnance is another issue. Magazines are being modified "so that rather than being weapon-specific [as originally designed], there will be a generic space where weapons can simply be stored in their transit containers," says James. "This offers much more flexibility. Illustrious is receiving these modifications during her current refit, with Ark Royal to follow."

Clearances are progressing for Harrier GR7 strike weapons. James says Raytheon's Enhanced Paveway II is "relatively straightforward as it is simply a fuzing change".

He adds: "A review of the safety case for the [Raytheon AGM-65] Maverick missile is under way and we hope to get a full release later in 2004. [MBDA's] Brimstone presents more of a problem as it is not an insensitive munition - the way ahead there remains to be decided."

Recovery aids

The provision of recovery aids for JFH aircraft is also being addressed. "The carriers are getting TACAN, which will help the Harriers locate the ship," says James. "Butin terms of poor visibility approach, they don't have the Madge [microwave guidance equipment] fitted to the Sea Harriers. Our studies looked at what it would taketo put Madge into the Harrier GR9 and update the fit on the ship. But, based on analysis of cost and risk, we've made thedecision to instead equip the carriers with precision approach radar, provision of which will be linked to the in-service date of the Harrier GR9.

"We are also looking at an option to use precision approach radar data [distanceoff centreline and glideslope] to pass information to the aircraft via a standalone ILS in the GR9. As yet we do not know if this would be feasible or affordable, although we are aware that similar technology has been demonstrated."

Another improvement to the ship/air interface is the provision of night vision goggle (NVG)-compatible lighting. "A UOR [urgent operational requirement] fit was put into Ark Royal for Telic which covered most things except visual approach aids," says James. "We have a study contract in place for a combined technical solution, leading to the development and implementation of a fully NVG-compatible package going into all ships."

The air group's training and readiness needs will have a greater influence on the programming of the carriers themselves, says James. "No longer can we programme the CVS and expect the TAG to fall into line. The ship's programme must create opportunities for all the aircraft types that might embark so they can both meet their training objectives and remain at high readiness while onboard. Similarly, we must make the ship available so that lower readiness squadrons can embark for short periods and develop the skills to deliver their aspects of air power from the sea."

Increasingly, the RN is focusing on how it prepares to bring together quickly a carrier task group matched to the UK's Joint Rapid Reaction Force readiness profile.

High readiness

"We need the carrier to go where the air group should be to make best use of overseas exercise opportunities," says James. "The rest of the time the ship will remain in or around UK waters for continuation training, remaining at high readiness for contingent operations.

"My view is that we must use the CVS and Joint Force Harrier in order to understand how best to operate CVF and the JCA. Of course there are limitations on what you can do with the current kit, but it offers valuable experimentation opportunities and a coherent path along which to take UK carrier air power into an altogether new era."


Source: Flight International