The Aviation Science

Hydraulic System 🛩️There are multiple applications for hydraulic use in aircraft depending on the complexity of the aircraft. For example, a hydraulic system is often used on small airplanes to operate wheel brakes, retractable landing gear, and some constant speed propellers. 🛩️On large airplanes, a hydraulic system is used for flight control surfaces, wing flaps, spoilers, and other systems. 🛩️A basic hydraulic system consists of a reservoir, pump (either hand, electric or engine-driven), a filter to keep the fluid clean, a selector valve to control the direction of flow, a relief valve to relieve excess pressure, and an actuator. 🛩️The hydraulic fluid is pumped through the system to an actuator or servo. A servo is a cylinder with a piston inside that turns fluid power into work and creates the power needed to move an aircraft system or flight control. Servos can be either single-acting or double-acting, based on the needs of the system. This means that the fluid can be...

Bleed Air from Engine 🛩️When air enters a turbine engine, it goes through a series of compressors, which significantly increase the air temperature and pressure before mixing that air with fuel and igniting it. A small portion of that compressed air, however, does not enter the combustion chamber and instead is redirected from the engine via valves, ducting and manifolds to various other areas of the aircraft. 🛩️Bleed air is extracted from the compressor of the engine or APU. 🛩️The specific stage of the compressor from which the air is bled varies by engine type. 🛩️In some engines, air may be taken from more than one location for different uses as the temperature and pressure of the air is variable dependant upon the compressor stage at which it is extracted. 🛩️Bleed air from that system can be utilized for internal cooling of the engine, cross-starting another engine, engine and airframe anti-icing, cabin pressurization, pneumatic actuators, air-driv...