This article considers airflow around mountain systems as a meso-scale atmospheric phenomenon. It presents a non-linear stationary dimensional theoretical model of the airflow of the North-West Caucasus Mountains, taking into account characteristics of a real mountain terrain. The article further discusses the results of the calculations of the speed field of the airflow and general regularities of the origin and the scale of the rotary-wave deformation of the airflow over the mountains. The calculation results have shown that for the model scenario I at wind speed U=15 m/s the disturbances are the most intense over the ridge crests, where they are characterized by the zone with rotors. The total length of the rotor zone downwind is more than the length of its nucleus and is close enough in value to the extent of the lee part of the terrain (downwind from the main top). The area of maximum amplitudes is located in the windward side of the rotor zone. These amplitudes are several times higher than the maximum height of the mountains. For the model scenario II (U=19 m/s) wave disturbances slightly increased in length downwind, but minimally changed in amplitude. The rotary zone changed and moved downstream. The model scenario III (U=22 m/s) is accompanied by sharp transformation of the rotor zone. Closed vortices disappear; there is no purely vertical and backward motion. The flow over the mountain greatly smoothed, and the rotor area completely disappeared. Flight safety indicators over the mountains of the Republic of Adygeya for two types of aircrafts (light-engine and speed) were calculated on the basis of the obtained data. In certain conditions, flights for both high-speed and single-engine aircrafts can be considered dangerous