Abstract. Aircraft hydraulic systems, especially on the Boeing 737 and Boeing 757 aircraft, are an integral part of their structure and operation. They play a key role in ensuring flight safety, cornering control, raising and lowering flaps, landing gear, and other important aspects of flight. The word” hydraulics “comes from the Greek word” water ” and originally meant the study of the physical behavior of water at rest and movement. Aircraft hydraulic systems ensure the operation of aircraft components. The operation of the chassis, rims, light steering and brakes is carried out mainly with the help of hydraulic power systems. In more detail, the comparative analysis of the Boeing 737 and Boeing 757 hydraulic systems is an important step in understanding and improving the technical characteristics and functionality of these models, which ultimately contributes to improving the quality and safety of aircraft transportation.

Key words: aircraft, design, hydraulic system, Pascal’s law, battery.