Hydraulic and Pneumatic Systems

Question 1

How is the air charge of an accumulator checked for proper servicing?

Answer 1

All hydraulic pressure must be bled from the system and the pressure is checked on the gauge

Question 2

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

Answer 2

An accumulator

Question 3

What are the three different types of accumulators?

Answer 3

1. Piston
2. Diaphragm
3. Bladder

Question 4

What safety precautions must be taken prior to disassembling an accumulator?

Answer 4

Release all of the air or preload

Question 5

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

Answer 5

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

Question 6

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

Answer 6

Landing gear, breaks, flaps, and other mechanical actuators

Question 7

Name several sources of pneumatic power

Answer 7

1. Storage bottles
2. Engine bleed air
3. Engine-driven compressors
4. Vane-type pumps

Question 8

What happens to excess pressure in a pneumatic system?

Answer 8

A relief valve vents it overboard

Question 9

What is the function of a restrictor in a pneumatic system?

Answer 9

To control the rate of flow of the airflow

Question 10

What are the reasons for periodically purging the pneumatic system?

Answer 10

To remove moisture and contaminants