FAA O&P- F.K.

What materials form the bases of the 3 types of hydraulic fluids?”

vegetable, mineral, and phosphate-esters

 What colors denote mineral based and phosphate ester based hydraulic fluids

mineral based fluids are red and phosphate ester based fluids are light purple

What are the results of exposing lacquers, oil base paint, plastic resigns, and vinyl compounds

the material will be damaged and/or softened/ or the paint will peel

Name several sources used to develop hydraulic pressure

hand pumps, engine driven pumps, and electronically driven pumps

What would cause the bypass valve in a hydraulic filter to open and allow unfiltered fluid to circulate in the system

clogged filter element

Describe several methods of pressurizing a hydraulic reservoir

engine bleed air, system pressure acting on a small piston in the reservoir, using variable-displacement hydraulic pumps

What feature prevents engine damage if an engine-driven hydraulic pump seizes or is overloaded

a shear section in the pump driveshaft will break, disconnecting the pump from the engine

Describe the purpose of a pressure relief valve

pressure relief valves limit the maximum pressure produced by the pump, thereby preventing failures of the system components

Engine-driven pumps deliver the output fluid flow in what two forms

as a constant volume or a variable volume

Describe the operation of a gear-type pump

two meshes gears, driven by a power source, rotate in a housing. Inlet fluid is carried around the outside of the gears and delivered to the outlet side as the gears rotate

Describe the purpose of a pressure regulator

pressure regulators manage the output of the pump to maintain system pressure. They allow the pump to be unloaded so it turns without significant resistance

What is the device that is used in some systems to supplement the pump output during periods of high demand

an accumulator

What are the three different types of accumulators

piston, diaphragm, and bladder

What safety precautions must be taken prior to disassembling an accumulator

release all of the air/preload

Why do some aircraft have fuel jettison systems

to allow the crew to reduce the weight of the aircraft down to or below the maximum allowable landing weight

When a hydraulic unit is replaced, what precautions should be taken to avoid contamination of the system

all lines should be capped or plugged immediately after they are disconnected

What types of components or systems are pneumatically operated in some aircraft

landing gear, brakes, flaps, and other mechanical actuators

Name several sources of pneumatic power

storage bottles, engine bleed air, engine-driven compressors or vane type pumps

What happens to excess pressure in a pneumatic system

a relief valve vents it overboard

What is the function of a restrictor in a pneumatic system

to control the rate of flow of the airflow

What are the reasons for periodically purging a pneumatic system

to remove moisture and contaminants