Abstract: A digital omputer program had been developed for studying a single-rotor helicopter with an externally suspended load. This report includes the descriptions of the motion equations of a helicopter with external loads and the calculation of all parameters of this equations (mathematical model), desired mission trace equations and load equations,principle of trim calculation of attitudes and control inputs, principle of integrations of motion equations when the helicopter flies according to the desired mission track. The computed errors are less than one of ten thousand. This program can be used in simulator of a helicopter with an external loads to train pilots, to predict the possibly exited question and to analyse the feasibility of construction (such as power transmission line construction) by a helicopter with external suspended load.

Key words: helicopter, computer simulation, externally suspended load