Trim and performance in axial and forward flight

The values of the flight parameters, such as collective pitch and inflow ratio, are necessary not only to know the control displacements required to maintain a given flight condition but also because these are needed for performance and stability calculations. A method that enables calculation of these quantities for a given helicopter under given steady-flight conditions is needed. Having solved the trim equations, one can calculate the corresponding power and establish relationships between a given set of flight conditions and the power required to achieve them. It is of interest to calculate quantities, such as the maximum speed and maximum rate of climb, for this purpose, and it is easier to consider the maximum power available to the rotor and to solve an energy equation. When trim and energy equations are based on the same set of assumptions, one can choose as per convenience. Analysis and discussion are based on the comparatively simple formulae.