Flight control

Airbus is planning its first flight tests later this year of ‘mini-flaps’ for aircraft wings, designed to reduce drag during take-off and increase stability by adapting to wind conditions.

The small trailing edge control devices, which measure just a few centimetres across and can rapidly deflect, could offer an effective way to change the aerodynamics of the wing’s trailing edge.

The flaps have been developed as part of the 80m Euro (£55m), four-year Awiator (Aircraft Wing With Advanced Technology Operation) project, which is due to be completed in 2007. Awiator, led by Airbus Germany, is investigating technologies to create lighter, intelligent aircraft that can respond to changing conditions.

The devices will be installed on Airbus’ A340 test aircraft over the next month or two. Flight tests are planned for the second half of the year, and will last until the end of 2005, said Rolf Henke, Awiator project co-ordinator at Airbus Germany. ‘We will modify the flaps and install these mini-flaps on to the modified flaps,’ he said.

‘They can help in aircraft take-off, to give a better lift-to-drag ratio, they can allow for a steeper, less noisy descent, and they may help in cruise, to adapt [to the conditions].’

Each wing could be fitted with around four or five of the control devices. They could work in conjunction with gust sensors, which are also being developed in the project, and would be mounted on the wing’s leading edge to detect pressure pockets and wind shear.

The gust sensors would detect turbulence in front of the aircraft and communicate instantly with the mini-flaps, said Henke.

‘One potential of the mini-flaps is that they could be used to react to the gust, so we know it is approaching, and we can deflect the mini-flaps at high speed. They would prepare the aircraft for the incoming gusts, to increase comfort and reduce structural weight.’

The gust sensors will be integrated with the mini-flaps and other technologies in further flight tests to be held next year, he said.

The EU-funded Awiator project involves 23 organisations including EADS, GKN Aerospace, and Israel Aircraft Industries. The project is also investigating devices for measuring and potentially manipulating wake vortices behind aircraft, more efficient airbrakes for rapid descent in emergencies, and new techniques to manipulate aircraft loads.

The technologies should mean wings will not need the same level of strength as today, as the load on them could be instantly distributed. This would mean they could be lighter and less rigid, resulting in a thinner skin and thinner ribs supporting the wings, increasing fuel efficiency.