Andrew Doyle/LONDON

LUCAS AEROSPACE's Power Systems division is studying the next stage in the development of so-called "more-electric" aircraft concepts, following its successful bid to introduce variable-frequency generators on Bombardier's Global Express business jet.

The company is focused on developing high-power variable-frequency generators for larger airframe applications, but the work could eventually lead to the elimination of engine-accessory gear boxes altogether, with a so-called "switched-reluctance" generator located on the engine's shaft being employed instead.

"The work we've been doing has led us to consider that aspect," says Bob Gibson, Power Systems' sales and marketing manager.

Lucas has pioneered the use of variable-frequency generators alongside turbofan engines, and is understood to have held discussions with Boeing about the possibility of incorporating the technology in the next generation of 737s. Lucas says that using a variable-frequency generator instead of a constant-frequency generator eliminates the need for a constant-speed drive mechanism, reducing cost and weight and boosting reliability.

The company is "...looking at the next steps towards an all-electric aircraft", says Gibson. "It is in our long-term strategy. We're being pushed along by the engine manufacturers and airframers," he adds.

Rolls Royce, meanwhile, has carried out studies, which show that increased use of electric systems on engines would reduce weight and offer lower fuel consumption and improved reliability, compared with contemporary design.

The studies also found that an all-electric Boeing 767-sized aircraft could have a 10% lower operational empty weight and could consume around 9% less fuel on a typical flight.

An all-electric aircraft would have no hydraulic systems, with flight-control surfaces and possibly even undercarriage retraction being electrically powered.

R-R is understood to have held preliminary discussions with several airframe manufacturers and suppliers, as it considers how much of its development spend should be channeled into work on more-electric engines.

Source: Flight International