Weigh less, pay less

Research at Manchester University intended to improve some of the systems used on private jets and short-haul aircraft could help spark the development of cheaper, lighter and greener small passenger planes.

As demand for air travel grows, it is likely there will be increasing amounts of short-haul travel and journeys by private jets.

This will be particularly true within the EU as the countries of eastern Europe expand their trade with the West, requiring operators to increase the number of flights between these nations.

While modern hi-tech jumbo jets such as the Airbus A380 feature advanced electrohydraulic and electromechanical systems to control equipment such as the rudder, small passenger aircraft still use control systems operated by wire-and-pulley that have not seen any significant technical advances for many years.

Led by Dr Nigel Schofield, researchers from Manchester University's School of Electrical and Electronic Engineering power conversion group is trying to improve the electrical systems that operate external flight control surfaces such as the rudder, wing flaps and the landing gear. They hope this will lower development, running and maintenance costs for such aircraft while still ensuring good passenger safety and comfort — as well as reducing the impact on the environment.

The work forms part of the EU-funded Cost Effective Small Aircraft (CESAR) project, which began last September and will run for three years. It involves 35 commercial and academic organisations from across the EU.

'Companies have expertise in particular areas, but they need to come and work together on a research and technology development project such as this,' said Schofield. 'We will not be creating an entirely new aircraft from scratch, but we will be changing much of what is within it. One single company would find it very hard to do something like it, so the EU funding will help to make the connection.'

The aim of CESAR is to produce a concept aircraft with between 10 and 50 seats. The group hopes to have a prototype of the control systems built by 2009, when there is the possibility of more funding that will enable them to create a flight demonstrator.

Within CESAR, the Manchester team has received a grant for almost £300,000 to investigate advanced electrical engineering methods for controlling the moving parts of smaller aircraft.

The researchers say that the introduction of electromechanical and electrohydraulic systems will reduce mass and bring significant improvements in energy efficiency — thus lowering the cost of aircraft manufacture and operation.

Replacing bulky mechanics and hydraulics with systems that are more electrically based may also allow a small aircraft to carry more passengers by increasing their available payload. Although the CESAR aircraft will not solve the problem of how to significantly reduce the emissions from air travel, it will reduce the carbon footprint of each traveller.

Similarly, with reduced weights, planes will require less fuel and produce less carbon dioxide.

Across the aerospace industry, there is a general move towards replacing traditional control systems with electrical ones. By doing this, Airbus has saved around a tonne of mass from the A380 superjumbo — the equivalent of eight passenger seats.

The advantages of improving the technology behind the control systems of smaller aircraft are becoming recognised globally.

'Worldwide, aircraft manu- facturers are looking at similar systems to this,' said Schofield. 'If the EU can manage to take the technology up a step then it will create a good commercial advantage.'

Although he admits that the introduction of new technology will result in the aircraft having a higher initial cost, this will be more than offset by savings on fuel.

'Capital outlay will definitely be higher as you are replacing a simple system with something more complex,' he said. 'However, it will bring significant financial benefits in terms of efficiency.'