Aircraft

Airbus UK has applied for a US patent for an A320 power system that stores the kinetic energy of rotating wheels in order to help retract and deploy the landing gear and brake the aircraft on landing.

Benefits of the scheme, according to Airbus, include cutting down on the number of redundant cable and pipe runs between centralized electric, hydraulic or pneumatic power generators, typically driven by the engines, and the localized functions, like landing gear extension and retraction systems.

In addition to reducing the weight of the aircraft and scavenged power from the engines, a localized regenerative system would require less maintenance and be less vulnerable to damage along the considerable lengths of cable and pipe runs, says Airbus.

Not mentioned in the patent application are the obvious green benefits, which would result from burning less fuel in lieu of regenerative energy production.

The system would use generators coupled to one of more of wheels on the landing gear. When the wheels spin during takeoff, the generators produce electrical energy which is then stored in a battery or other energy storage device. The stored energy would then be used to retract the gear after takeoff.

During landing, the gravity-assisted free-falling landing gear would internally generate power via the damping system that would then be used to spin up the wheels, which in turn would provide power to complete the landing gear deployment.

Once on the ground, the wheels' kinetic energy would be used to partially or fully power the braking system.

The wheel-based generators, working in reverse, would appear to be suited to Airbus plans to test an electric taxiing system for A320. The airframer in May said the prototype device would include electric motors in the wheels powered by the aircraft's auxiliary power unit for taxi operations.