Reinventing powered flight

The DTI is backing civil research into plans for `the more-electric aircraft’, to cut the lifetime cost of airliners, writes George Paloczi-Horvath

By autumn, British industry will be starting its search for ways to develop a so-called `more electric aircraft’. The aim is to cut a civil airliner’s whole-life costs by at least 3%. The method could be by replacing many of its hydraulic and pneumatic systems with lighter, cheaper and more reliable electric and electronic alternatives.

A £3m Department of Trade and Industry-led challenge to develop the more electric aircraft was launched in February. Industry expressions of interest were received in March and outline proposals are due by the beginning of May. By June these will be sifted by an industry and academic panel, allowing full proposals to be assessed by August. The first grants will be provided by October.

Under the DTI’s Civil Aircraft Research and Demonstration (Carad) programme, this challenge will fund up to 50% of eligible costs to avionics companies to stimulate research into various very advanced technologies.

A DTI insider says there are many power systems around an aircraft which could be examined.

`Hydraulics are used a lot in actuating an airliner’s flaps or the undercarriage,’ he says. `Such systems are quite heavy and costly, and there are important improvements to be made in moving to electric actuators in the distribution of power. A single wire is better than pipes around the aircraft with high-pressure fluid in them.’

With electrical wiring controlling wing actuators or undercarriage, the weight of an airliner could be dramatically reduced. Pneumatic power could also be replaced by electrical power, the DTI suggests.

There are further advantages. The shift to more electrical systems may make possible improvements to airframe design. Airliner maintenance and reliability could also be improved, the DTI says, contributing to the cut of 3% or more in a civil aircraft’s through-life costs.

`In order to do this, we need to do some work in improving the generation, control, distribution and consumption of power in a future civil aircraft,’ the DTI says. This is where the advanced technologies will come in. Separate overall studies could also be included in the scope of the work, to look at how all the research can be integrated.

The whole programme is looking at technologies in three main areas: components, equipment and systems. Components include power electric and sensor devices, connectors, insulation and novel cables.

Equipment will include solid state switches, generators and starters, fuel pumps and electromagnetic bearings. Systems includes computer architecture, simulation and analysis tools and failure detection and isolation tools.

The DTI suggests that the idea is to go a lot further than the `fly-by-wire’ technologies introduced in a civil airliner for the first time with the Airbus A320 in 1988.

Fly-by-wire was developed for military aircraft long before its A320 application. A fly-by-wire aircraft control system does away with mechanical cables from pedals and control columns and puts an electronically controlled hydraulic link between the pilot and control surfaces such as flaps. `What we’re doing is refining that to move to all-electric, rather than a mix of hydraulic, pneumatic and electric parts,’ the DTI says.

`One can introduce a more electric concept into existing aircraft. While it would not be economic to retrofit a whole aircraft with new systems, there are opportunities to introduce some aspects at shorter notice.’

The DTI is running the three-year challenge in its aerospace and defence industries directorate and says that, although it is aimed at civil aircraft, `where some of the items could be of interest to the military we will try to bring in MoD funding to support these objectives’. The DTI also intends to talk to the research councils about their potential funding of universities towards this end.

Under Carad rules there must be more than one company in each group applying for funding. All the results of a research programme will belong jointly to the group partners.

In February, industry minister Greg Knight said that research into the more electric aircraft had been identified as a high priority by the aeronautics industry because of its potential benefit to competitiveness. Although the challenge is not directly linked to the Technology Foresight process, the ADI directorate is on the Foresight defence and aerospace panel and Foresight `has been providing a framework within which Carad has been operating’, the DTI says.

At the conclusion of the three years of research, there will probably be no general report on its findings, as the DTI will not own any of the results. `But we do insist that they’re exploited,’ the DTI says. `If companies do not exploit something within a reasonable time, we have the right to disseminate it to other companies.’