Operational restrictions imposed on the parameters of the flight of the helicopter on the modes "pickup", "vortex ring", when unmanaged autorotation of helicopter, on the modes of hovering and take-off and landing modes are considered. Requirements to channel of the information-management system to prevent critical modes of the helicopter are validate. The reasons origin of critical modes of flight of helicopter, a method of assess their level of risk with the use of private (individual parameters of flight) and integral (mode of flight in general) functions of the danger are describes. Connection of informative functions of danger with the dynamics of helicopter's action is shown. Formulas for determining the speed of change in time and the vector of gradient of the integral function of the danger of flight helicopter on the phase coordinates of the state vector of the helicopter, the parameters of the vector of control and vector of perturbations are shown. Methods of forming alerts, building of control algorithms and decision-making on the criteria security with the use of vector of gradient integral function the danger of mode flight helicopter are disclosed. The methodology for describing the vector of gradient of integral function of danger of the mode flight helicopter in dimensionless parametric form convenient for practical implementation in the channels of the information-management system to prevent critical modes of the helicopter are shown. It is shown that the investigation of the behavior of the full derivative on time of the integral function of danger of mode flight helicopter, enable to make informed decisions on constructing of algorithms wheel and automatic control, providing the quickest exit from arising emergency situations. The effectiveness of the used approach are illustrated by the example mode "vortex ring". Method of constructing algorithm proactive alarm using the informative functions of danger of mode of flight of the helicopter is disclosed, correlations for the formation of static and dynamic feed forwards. Using lines of level parity risk is disclosed version of the construction of the indicator of safety channel information support crew in emergency situations.