Hydraulics

Question 1

What is the maximum hydraulic pressure?

Answer 1

3,500 psi

Question 2

Hydraulic system A pressurizes which components?

Answer 2

Landing gear
Normal N/S steering
Ailerons
Rudder
Elevator
Elevator feel
FLT spoilers
Grd spoilers
ALTN brakes
Thrust reverse 1
Autopilot A

Question 3

Hydraulic systemB pressurizes which components?

Answer 3

Alt N/W steering
LE slats flaps
Auto slats
Ailerons
Rudder
Elevator
Elevator feel
Flt spoilers
TE flaps
Normal brakes
Thrust reverse 2
Autopilot B
Yaw damper

Question 4

What conditions will cause automatic activation of the standby hydraulic system?

Answer 4

Loss of system A or B
Flaps extended
In flight or a wheel speed greater than 60 knots
FLT CONTROL switch A or B hydraulic system on

Question 5

Once the standby hydraulic system is activated, a single electric motor driven pump provides power to which ?

Answer 5

Rudder
Extend the leading edge flaps and slats
Either thrust reverser
Standby yaw damper

Question 6

A TANDBY HYD LOW QUANTITY light illuminates for what reason?

Answer 6

Fluid level drops below 50%

Question 7

What system is in place to prevent total loss of hydraulic fluid in System A

Answer 7

A stand pipe in the engine driven pump supply line. It’ll keep 20% of the fluid.
There is no protection in the electric pump should a leak occur

Question 8

What is the power source for system A electric pump?

Answer 8

AC Transfer Bus 2

Question 9

What is the power source for system B electric pump?

Answer 9

AC Transfer bus 1

Question 10

For the heat exchanger to provide proper cooling, what minimum amount of fuel must be in the wing tanks?

Answer 10

1675 lbs

Question 11

What is the purpose of the landing gear transfer unit?

Answer 11

To help raise the landing gear at a normal rate using system B hydraulic volume

Question 12

What conditions need to be met for the landing gear transfer unit to work automatically?

Answer 12

Aircraft in flight
No1 engine RPM drops below a limit value
Landing gear lever is up
Either main landing gear is not up and locked

Question 13

What is the PTU?

Answer 13

Power transfer unit, it is a hydraulic motor-driven hydraulic pump
It uses fluid under pressure from system A to drive a pump which in turn pressurizes system B

Question 14

Which controls does the PTU operate?

Answer 14

Leading edge flaps
Slats
Autoslat operation

Question 15

When does the PTU operate automatically?

Answer 15

System B , engine-driven pump pressure drops below a limit
Aircraft is in flight
Flaps are less 15 but not up

Question 16

What is the meaning of an Illuminated OVERHEAT light on the Hydraulic panel?

Answer 16

1. The pump itself has overheated
2. Hydraulic fluid used to cool and lubricate the corresponding electric motor-driven pump has overheated