Flying start

The Royal Navy’s next-generation aircraft carriers are likely to be fitted with a new electromagnetic aircraft launch system being developed in the UK and US.

The catapult will be more powerful yet smaller, lighter, cheaper and easier to control and maintain than a conventional steam-driven catapult. While the UK is funding its own demonstration programme, EMCAT (the Electromagnetic Catapult), construction of prototypes of two rival catapult designs for the US Navy is to begin at Lakehurst, New Jersey, in November.

Known as the Electromagnetic Aircraft Launch System (EMALS), testing with dummy aircraft begins in mid-2003. The demonstrators will be three-quarters the size of – but just as powerful as – the final 100m version. Following the competition, between General Atomics and Northrop Grumman, the winning EMALS design will be used on the US Navy’s next generation carrier, the CVNX.

Though conceived in the 1940s, advances in alternator and cycloconverter technology have only recently made the idea a possibility. Alternators provide the electrical energy while the cycloconvertor controls the electric pulse that helps accelerate the aircraft.

Last month, the Ministry of Defence confirmed that it would select the Short Take-Off and Vertical Landing (STOVL) version of the Joint Strike Fighter (JSF). It was previously thought that it would want either a carrier designed only for this plane or a carrier designed only for conventional aircraft. The former would have been too small for a catapult and would have needed a ‘ski ramp’ to help the JSF get into the air. Instead, the MoD has decided it wants a conventional-type carrier large enough, and the right shape, to be ‘fitted for but not with’ a catapult. It will initially be fitted with a ski-ramp.

Rejecting the option to fit the carriers with a normal steam-operated catapult from the start clears the way to being able more easily to retrofit EMCAT, said an industry source. The system would also work better in conjunction with a carrier’s electric propulsion system than a conventional catapult, which would require excess high-pressure steam from the propulsion system.

‘Future-proofing’ the design specification in this way allows the navy to adopt non-STOVL aircraft at a later date. Notably, the Maritime Airborne Surveillance and Control aircraft needed to accompany the JSF require catapult-assisted take off.

BAE Systems and Thales Naval are competing for the £2.7bn order to introduce the two carriers into service in 2012 and 2015; the winner should be named early next year.