Abstract: This paper is limited to study an aircraft in a landing sequence and in a wheel braking process, which is operating in ground effect. The Aircraft models of three freedom in run are given firstly in this paper, i.e. aircraft forward translation, aircraft vertical translation, and pitching rotation. The constant lift coefficient and drag coefficient are assumed as the aircraft is assumed to be a rigid body.The dynamic characteristics of under carrige, brake, wheel , friction law between tyre and ground surface are analysed in this paper too. The landing gear dynamics are considered to be analogous to mass-spring-damper dynamics. The tire derformation is also neglected, so that the vertical gear loads will act through the center of the wheel. Finally , the brake curves for x type aircraft are given here.

Key words: aircraft, electronic antiskid brake system, analogue simulaion