Hydraulics

Question 1

When pressurizing the hydraulics which pump is turned on first and off last? Why?

Answer 1

Right electric dmand pump. To prevent fluid transfer between systems.

Question 2

What is the purpose of the demand pumps?

Answer 2

The demand pumps provide supplementary hydraulic power for periods of high system demand.

The demand pumps also provide a backup hydraulic power source for the engine–driven primary pumps.

Question 3

When do demand pumps run?

Answer 3

In the AUTO position, the L and R demand pumps operate for takeoff, landing, and when system or primary pump pressure is low.

In the ON position, the demand pump runs continuously.

Note: In the AUTO position the right demand pump operates continuously when the airplane is on the ground.

Question 4

What does the associated demand fault light mean?

Answer 4

• low output pressure
• high fluid temperature, or
• demand pump is selected OFF

Question 5

Which hydraulic system reservoirs have standpipes?

Answer 5

L,C,R

Question 6

What are the standpipes for?

Answer 6

Reserve fluid for the demand pumps.

Question 7

What is the significance of the standpipe and the demand pump in the center system?

Answer 7

The fluid below the standpipe in the center hydraulic reservoir is used by the primary C1 pump as a reserve hydraulic source to power the alternate brakes and nose wheel steering.

Question 8

What system powers normal brakes?

Answer 8

Right

Question 9

When normal brakes are lost do you still have anti-skid?

Answer 9

The alternate brake system provides antiskid protection to tandem wheel pairs for the forward and middle axle wheels. The aft axle wheels remain individually controlled.

Question 10

What things are on the left hydraulic system?

Answer 10

Spoilers, ailerons, flaperons, elevator, rudder, left thrust reversers

SAFER LTR

Question 11

What things are on the right hydraulic system?

Answer 11

Spoilers, flaperons, elevator, rudder, right stab trim, right thrust reverser, normal brakes

SFERRR NB

Question 12

What things are on the center hydraulic system?

Answer 12

Spoilers, ailerons, flaperons, elevator, rudder, left stab trim, alternate reserve brakes, nose gear steering, landing gear actuation, main gear steering, trailing edge flaps, leading edge slats

8 up, 4 down

Question 13

What things does the RAT power on the center hydraulic system?

Answer 13

Spoilers, ailerons, flaperons, elevator, rudder, left stab trim

SAFER LST