Hydraulic System: I chose to discuss the importance of the aircraft's hydraulic system to the class.  Aircraft's hydraulic system is a necessity when it comes to pilots flying the aircraft, because it can be used to control various components on small and large aircraft such as flaps, brakes, thrust reversers, landing gear, nose wheel steering, rudder, and spoilers. The hydraulic system is used to assist the pilots in the movement of these components based on Pascal’s Law.  Pascal’s Law asserts that pressure applied to liquid anywhere within the enclosed system will cause equal pressure to be distributed everywhere else within that system (MacCready, 2017). The process is the pilot or crew member activates a hydraulic system with an input from a switch or flight control device (MacCready, 2017). The pump is activated, pressurizing the system, which puts the actuator in motion (MacCready, 2017). The movement of the actuator is directly transferred to the control surface or other device – such as landing gear, brakes, or spoilers – which is then moved into the desired position (MacCready, 2017). In order to reverse the movement, pressure is released from the system, and the opposite occurs (MacCready, 2017).

The loss of the hydraulic system would cause the pilots to have to use alternate methods to operate components. The alternate method will have a procedure or checklist specifically developed for each type of aircraft. In the Navy we use a platform specific Naval Air Training and Operating Procedures Standardization(NATOPS) which has procedures for in-flight emergencies and malfunctions. When I performed loss of hydraulic system checklist in the simulator, I had to manually lower the gear by cranking a handle, lower flaps electrically, turn off the rudder boost switch, and use pneumatic brakes. It was overall less efficient, because extending flaps and gear added on time, using the pneumatic brakes caused there to be no differential braking pressure, and rudder was limited to half of the normal deflection.

The only time I have experienced an actual hydraulic leak before was during a landing and it was not a fun day. I had a small hole in a hydraulic line that caused the hydraulic fluid capacity to deplete rapidly seeing how it was a pressurized hydraulic system. I had to get the aircraft towed back to the parking ramp and have a new hydraulic line fabricated. Fact of the matter is that hydraulic malfunctions are detrimental to safety of flight of all aircraft.

References:

MacCready, M. (2017, January 20). Aviation Hydraulics – What Is It and How Does It Work? Retrieved from flytekgse.com: https://flytekgse.com/2017/01/20/aviation-hydraulics-2/