Hydraulic and Pneumatic Power Systems

Question 1

What are three types of hydraulic fluids?

Answer 1

Vegetable, mineral and phosphate esters

Question 2

Which color do mineral base and phosphate ester hydraulic fluids have?

Answer 2

Mineral - Red
Phosphate ester - light purple

Question 3

What happens to plastic resin‘s, vinyl, compositions, lacquers, and oil base paint if exposed to a phosphate ester base hydraulic fluid such a Skydrol?

Answer 3

It becomes damaged, softens or peels

Question 4

What precaution should be taken to minimize contamination during replacement of a hydraulic unit?

Answer 4

All lines should be plugged or capped after disconnecting

Question 5

What would cause a hydraulic filter to go into open bypass, allowing unfiltered fluid into the system?

Answer 5

A clogged filter

Question 6

What are two types of engine driven hydraulic pumps?

Answer 6

Constant-delivery, and variable-delivery

Question 7

How does a gear type power pump operate?

Answer 7

Two meshed gears are driven by a power unit rotating in the housing. Fluid is carried around the outside of the gears and delivered to the outlet side as the gears rotate.

Question 8

What feature is built into a hydraulic pump-driven system to prevent engine damage in the event of pump seizure or overload?

Answer 8

A Shear action in the pump drive shaft occurs

Question 9

What is the purpose of a pressure relief valve?

Answer 9

To limit the amount of pressure to prevent failure of system components

Question 10

What is the purpose of a pressure regulator?

Answer 10

To manage the output of the pump to maintain system pressure, and to allow the pump to turn without resistance

Question 11

What is used in some hydraulic systems to supplement the power pump on several units are operating at the same time?

Answer 11

An accumulator

Question 12

What are the different types of accumulators?

Answer 12

Piston, diaphragm and bladder

Question 13

What must be accomplished with any accumulator prior to disassembling?

Answer 13

Make sure that the air or preload has been discharged

Question 14

For what purposes are pneumatic systems used in some aircraft?

Answer 14

To operate brakes, doors, drive pumps and engine starting

Question 15

What’s are sources of pneumatic power?

Answer 15

Storage bottles, vane-type pumps, and turbine engine compressor

Question 16

What is the purpose of restrictors that are used the most aircraft pneumatic systems?

Answer 16

To control the rate of flow

Question 17

What happens to excessive pressure in a pneumatic system?

Answer 17

A relief valve will bleed it to the atmosphere

Question 18

Why should a pneumatic system be purged periodically?

Answer 18

To remove contamination and moisture

Question 19

What are the results of exposing lacquers, oil based paint, plastic resin’s in vinyl compounds to phosphate, ester-based hydraulic fluid?

Answer 19

Materials will be damaged, softened, or paint will peel

Question 20

Name several sources used to develop hydraulic pressure?

Answer 20

Hand pumps, engine driven pumps and electrically driven pumps

Question 21

What type of components or systems are pneumatically operated in some aircraft?

Answer 21

Landing gear, brakes, flaps, and other mechanic actuators

Question 22

Name several sources of pneumatic power

Answer 22

Storage bottles, engine bleed air, engine driven compressor, or vane type pumps