London, April 2 : Researchers at Bristol University, UK, are developing an aircraft with an "elbow" in each wing that can tilt the wing tips up or down, which could result in aircraft that are more efficient and maneuverable than traditional fixed-wing craft.
According to a report in New Scientist, by developing an aircraft with wing tips that temporarily hinge upwards, changes the wing's aerodynamics, and allows the aircraft to be manoeuvred without using traditional control surfaces like elevators and ailerons.
"With bending wing tips you have better aerodynamics," said Patrick Bourdin, an aerospace engineer working on the project.
Aircraft with wings that "morph" in this way can initiate turns at low speeds without stalling or experiencing control reversal, and can manoeuvre more sharply than conventional designs, the report said.
Bourdin and his colleagues call the movable wing tips "wingletrons".
For level flight, they are angled slightly upwards relative to the level part of the wing. But they can also be lifted further or lowered to be anywhere between level with or perpendicular to the rest of the wing.
In a standard airplane, a fixed wing provides the lift, while separate movable control surfaces control the three possible rotations of the craft: pitch, yaw and roll. With the new design, movement of the wingletrons alone can control movement in all three directions.
For instance, if one wingletron is raised to a 90 degree angle, that wing produces less lift than the other, and the aircraft begins to roll towards the folded wingletron. Folding one wingletron up also causes the craft to yaw - move the nose left or right - toward the folded wingletron.
To control pitch - moving the nose up or down - both wingletrons are moved at the same time. Folding both up tilts the nose upwards. Bringing them down flat with the rest of the wing tilts the nose down.
To provide more manoeuvrability, the model in the flight tests combined conventional elevators with the wingletrons.
But Bourdin said that he plans to build a craft that has split wingletrons, providing a total of four control surfaces. Then one pair could be used to adjust pitch, while the other pair adjusted roll and yaw.
Because the wingletrons give good manoeuvrability at low speeds, they are a promising approach for unmanned aerial vehicles carrying surveillance cameras, for example.