In the present chapter we introduce basic coordinate systems used in flight dynamics, investigate motion equations of an aircraft in the body-axes system, discuss the forces acting on an aircraft, consider problems of motion of systems of variable mass, give formula for the jet engine thrust, study aircraft motion in the launch coordinate system, and apply methods of nonholonomic mechanics for aircraft targeting. It is also pointed out that flight dynamics is concerned with motion of airplane and launch vehicles in the Earth atmosphere and its methods can be applied to the study of motion of submarines and surface ships.