Abstract:The civil aircraft wheel speed transducer is one of the key equipments in the aircraft brake system, used for antiskid control of the brake system, to prevent the wheel skid and lock in the process of braking. This paper briefly introduces the development history of foreign aircraft wheel speed transducers with antiskid braking system, and expounds four types of wheel speed transducers, namely variable reluctance type, directcurrent type, hall type and photoelectric type, from aspects of working principle and structure. At present, the mainstream civil aircrafts (including A320, A330 and Boeing 737, Boeing 747, Boeing 777 and other models) all adopt the variable reluctance wheel speed transducer, which has diverse product forms and is a matured product. Hall type wheel speed transducer with the advantages of small size, light weight and fast response speed, is used in Boeing 787 civil aircraft, and it has a good application prospect. According to the public data, the directcurrent wheel speed transducer is used in the Concorde aircraft but its complex structure and low reliability handicap its application. The photoelectric wheel speed transducer requires low vibration, and the current technology can not meet the harsh environment of the wheel, so there is no installed product at present.