The present invention relates to an aircraft including an apparatus for measuring the load sustained by an aircraft component and to a method of measuring such a load. In particular, the present invention relates to an apparatus for determining the load sustained by an aircraft when braking and/or maneuvering the aircraft on the ground.
When an aircraft maneuvers on the ground (including, for example, immediately after touch down), the aircraft is subjected to various loads including vertical wheel to ground loads and horizontal drag loads including, for example, loads caused by friction between the tires of the wheels of the aircraft and the ground. The landing gear is subjected to significant horizontal loads on braking. The landing gear and other components of the aircraft have to be carefully designed in order for the aircraft to be able to withstand such loads, and other operational loads, but without unduly increasing the mass of the aircraft.
By using a load measuring device as part of a feedback braking system it is possible to limit, at least in part, the maximum load sustained by the airframe, landing gear, or a part thereof and/or to facilitate efficient braking of the wheels. It may also be advantageous to use load measuring devices during the testing and development of new aircraft.
It is known to use strain gauges as part of such load measuring devices. These, however, have disadvantages associated with them. For example, strain gauges may have to be bonded to the structure being monitored, may require specialist maintenance, may only be able to provide a local load measurement, may be easily damaged, may be susceptible to noise and/or may require temperature compensation.