The most exciting part of the Royal Navy's future, is its return to a large aircraft carrier: the so-called CV(F). The Strategic Defence Review (SDR) first introduced the need for a larger aircraft carrier to replace the Invincible Class aircraft carriers which the RN possesses at present.

The development of the CV(F) is very much still in the development stage. What is known is that there will be two in the class and that they will be 35-40,000 tonnes, i.e. nearly twice the displacement of the Invincible class, and that they will use non-nuclear propulsion. There are three possible forms for the CV(F)

• STOVL
• STOBAR
• CTOL

Each style has its own advantages and disadvantages.

STOVL

There is some concern that if the decision is taken to build a STOVL CV(F) that the design will be cut-back into essentially a replacement Invincible class, of roughly the same size. Some believe that the STOVL is the preferred choice because that way JSF could enter service sooner and be used on the Invincible class post their SLEP programme. However the RAF may continue to have a use for STOVL aircraft and as such if an alternative CV(F) design is chosen then a small number could be ordered for use on the Invincible class and RAF until the Invincible is withdrawn.

Personally I would prefer not to receive a STOVL carrier as it is limiting the operations a carrier could perform. Also, there would be no solution to the problem of AEW, since the CV(F) would have to rely on helicopters and this is not necessarily the best option.

STOBAR stands for Short Take Off But Arrested Recovery. It is to some degree a hybrid STOVL/CTOL carrier. It would contain a ramp to help the aircraft take off on a short distance but an angled flight-deck to recover aircraft.

The advantages of a STOBAR carrier is that the range and type of aircraft can be increased somewhat. An aircraft that has poweful engines is required to achieve a take-off in such a short distance but would not need the ability to hover and perform a vertical landing. It is the vertical landing that needs the most power and fuel. That said, because it is a "traditional" landing there is, perversely, a higher chance of problems and it can take longer to recover the aircraft. On that basis a Buddy aircraft will be required to help refuel aircraft in the queue.

There are plans for a STOBAR version of both the JSF and the Eurofighter ("SeaTyphoon") and this would give a large variety of options to a CV(F). It is also possible that an aircraft could be designed for AEW duties so that a helicopter could be used, this would rapidly increase the abilities of a CV(F) Task Group.

Personally I think a STOBAR carrier is the preferred option. It would contain most of the advantages of both a STOVL and CTOL but without the disadvantages of each. CTOLs now really have to be the size of a Nimitz Class before they are very useful. The Charles de Gualle suffered from numerous faults as a result of trying to achieve a "mini-Nimitz" and I would prefer that the RN did not fall into that trap. A STOBAR carrier would be of a decent size, with a good range of aircraft and would be a powerful ship. There would be increased hangar space and facilities for flag-quarters, and other specialist duties.

CTOL stands for Conventional Take Off and Landing. This is what some would regard as a "proper" aircraft carrier. The aircraft are launched by catapult and recovered through an arrested angled flight deck.

The principal advantages of a CTOL carrier is that they can launch a variety of aircraft and that their range is normally greater than any other form of carrier. The disadvantages are that they require an angled-flight deck and a Buddy refueling system, and that they require catapults.

Traditional catapults are steam operated. Steam builds up in the piston and at the moment of release the piston and the "tray" it carries underneath the aircraft, shoot across the flight-deck which propels (hopefully!) the aircraft to the correct take-off speed. The problem with this system is that the required equipment is very bulky and needs a lot of power to produce the speed. The USN Carriers and, to some degree the Charles de Gaulle, do not suffer any great disadvantage here because with a nuclear power-plant, steam is in plentiful supply. However a convnetional-powered ship would need seperate steam generators.

That said, however, some are suggesting that the age of steam-catapults is gone and that electro-magnetic catapults are the way forward. This would get rid of some of the problems but would produce a lot more: for a start the technology is not yet available so there would be high development costs. Whilst it is likely that other countries (prinipally the USA) would be interested in joining such a research programme, it would still be expensive and use up a substantial part of the budget. On that basis I would prefer CTOL not to be the preferred choice, but for a STOBAR option to be employed.