Abstract
The necessity of analyzing and modeling process of the emergency landing unmanned quadrocopter is described. Through mathematical modeling the basic features of landing unmanned quadrocopter are considered. The methods of safe landing of an unmanned quadrocopter in case of failure of one of four pairs of motor-screw are proposed. The basis of the proposed methods is to use a parachuting effect. Parachuting achieved by forced off the power of the motor, which is located at the opposite end of the same yoke as faulty motor As a result, quadrocopter vertical speed at the time of landing is reduced significantly and is approaching a relatively safe value.