Revision Questions Hydraulics

Question 1

Compared to hydraulic actuating systems, pneumatic systems of the same operating pressure -

A. Are only used as a backup system
B. Exert less force
C. Exert more pressure
D. Are only used for landing gear extension

Answer 1

B. Exert less force

Question 2

A restrictor valve fitted to the landing gear hydraulic system is to -

A. Prevent hydraulic cavitation during gear extension
B. Prevent hydraulic cavitation during gear retraction
C. Shut off fluid supply in the event of a leak
D. Reduce the operating pressure of the system

Answer 2

A. Prevent hydraulic cavitation during gear extension

A restrictor valve restricts the speed of operation of the actuator to prevent cavitation

Question 3

The purpose of a shuttle valve in the hydraulic system is to -

A. Allow hydraulic pressure from the alternate system to pressurise the lines in the event of a failure of the normal system
B. Vent excess hydraulic system pressure back to the reservoir during periods of low demand
C. Allow extra hydraulic pressure into the lines to cope with periods of high fluid flow demand
D. Allow two seperate hydraulic systems to simultaneously supply pressure to services to provide redundancy

Answer 3

A. Allow hydraulic pressure from the alternate system to pressurise the lines in the event of a failure of the normal system

A shuttle valve allows the alternate system to pressurise the lines if primary pump fails

Question 4

The component of a hydraulic system which acts as a surge suppressor is the -

A. Reservoir 
B. Accumulator
C. Pressure relief valve 
D. Check valve
E. Pressure regulator

Answer 4

B. Accumulator

Question 5

A constant delivery hydraulic system requires -

A. A pressure accumulator
B. A pressure regulator
C. A shuttle valve
D. A hydraulic fuse

Answer 5

B. A pressure regulator

Question 6

The purpose of a hydraulic priority valve is -

A. To provide part of the sequencing valve
B. To shed non essential services due to a loss of system fluid
C. To shed non essential services due to a loss of system pressure
D. To select an alternate source of system pressure in the event of primary pressure loss

Answer 6

C. To shed non essential services due to a loss of system pressure