Transition of aviation to turbojet engines, which started actively in the forties of the 20th century, enabled significantly increasing flight speeds due to eliminating problems associated with peculiarities of propeller operation at high speeds. For many years, flights with turbojet engines at relatively low speeds (up to 500–700 km/h) were less cost-effective than on piston propeller airplanes. Development of aviation turbine technology has largely eliminated disadvantages of cost effectiveness. However, engines themselves have become more complicated, more expensive, but in recent years, the rate of increase in efficiency has been slow. The total fuel consumption increases due to the increase in traffic volume. Many problems in this area can be solved by using cost-efficient rotary-petal engines of internal combustion. Possible technical solutions for development of this area are shown.