Abstract: An advanced braking system for an aircraft is disclosed. A controller calculates the braking required from each wheel in terms of force. A constant deceleration is achieved throughout a braking run by calculating the braking from other sources, principally aerodynamic drag, and commanding a complementary total level of braking from the wheel brakes. The performance of each wheel and brake are monitored during the braking run to determine whether their braking performance is limited by the brake discs or by the tyre-ground interaction and to see whether the wheel is approaching the maximum slip ratio after which a skid occurs. The controller uses this information to distribute the total demand for braking amongst the wheels. In doing this, it also aims to keep the braking demand symmetrical across the aircraft and not to overheat the brakes. The controller further measures the braking force provided by a wheel and controls its brake pressure accordingly to achieve the force desired.

Abstract: The load on an aircraft component, such as the load on a landing gear leg during braking, is measured with a contactless, all-weather displacement measuring system. The system includes a processing unit, a plurality of controllable microwave emitters of electromagnetic radiation including a pulsed time-coded signal (PTCS) and a microwave detector comprising a plurality of antennae. When the aircraft component is subjected to a load relative movement of the emitter and detector is caused. The antennae of the detector generate in response to microwave radiation received from PTCS emitted by the emitter signals that are received by a signal processor of the processing unit. The timing of the signals received by the processing unit depends on the relative positions of the emitter and detector. With the use of triangulation techniques, the processing unit provides an output signal representative of the load sustained by the aircraft component.

Abstract: The load on an aircraft component, such as the load on a landing gear leg during braking, is measured with a contactless, all-weather displacement measuring system. The system includes a control unit a controllable microwave emitter of electromagnetic radiation and a microwave detector comprising a plurality of antennae. When the aircraft component is subjected to a load relative movement of the emitter and detector is caused. The detector generates in response to microwave radiation received from the focused beam of radiation emitted by the emitter a signal that is received by a signal processor of the control unit. The signal received by the control unit depends on the relative positions of the emitter and detector. The control unit is arranged to provide an output signal representative of the load sustained by the aircraft component. The system may be used to control braking in dependence on the output signal so as to maximise braking efficiency without overloading the landing gear leg.