Systems - Hydraulic

Question 1

Name the Hydraulic Sub-Sytems

Answer 1

Brakes
Nosewheel steering and shimmy damping
Rear loading door
Flaps

Question 2

How is hydraulic pressure produced normally?

Answer 2

Electric Hydraulic Pump (variable displacement, 2000 psi)

Limitation: 25 minutes ON . . . 25 minutes OFF

Question 3

How is hydraulic pressure produced abnormally?

Answer 3

Standby Hand Pump, SIC right-hand side.

Question 4

Hydraulic reservoir location?

Answer 4

Right wheel sponson.

Question 5

Hydraulic System Capacity?

Answer 5

11 liters

Question 6

Describe the hydraulic pre-flight inspection.

Answer 6

Parking Brake . . . OFF
Flaps . . . UP
Rear Loading Doors . . . CLOSED
Accumulators (3) . . . DISCHARGED

Question 7

What sub-systems are pressurized by the Standby Hand Pump?

Answer 7

All four –

• • Brakes
• • Nosewheel steering and shimmy damping
• • Rear loading door
• • Flaps

Question 8

Hydraulic Safety Valve location and operation.

Answer 8

Location –
– between the pressure and return lines

Operation –
– Automatic at 2350 psi

Question 9

Hydraulic Pump Operating Limitation protects against?

Answer 9

Excessive thermal expansion of the of the fluid.
– 25 minutes ON . . . 15 minutes OFF
(Ref: CASA 212 Systems Description 5-4)

Question 10

Which sub-systems have accumulators?

Answer 10

• Nosewheel Steering and Shimmy Damping
• Parking / Emergency Brakes
• Main Foot Brakes (with differential braking, and approximately 30 applications)

Question 11

How is braking priority determined?

Answer 11

Shuttle valves give priority to the pilot applying greater pressure to each pedal. Additional shuttle valves give priority to the Main Foot Brakes or parking brake - whichever is exerting greater pressure.

Question 12

How is applied pressure at the Main Foot Brakes proportional to Braking Pressure?

Answer 12

Directly. Light pressure at the foot brake peddles equates to light braking pressure, and then directly until maximum peddle pressure (88psi) to maximum braking pressure (1140psi).

Question 13

How is pressure on the Parking Brake Handle applied to Braking Pressure?

Answer 13

Braking pressure is directly proportional to the pressure being applied at the Parking Brake Lever. No differential braking, equal pressure to both brakes.

Question 14

Approximate number of braking applications from accumulator?

Answer 14

30 applications –
– Main Foot Brakes

30 applications –
– Parking Brake Lever