PC-21 Nose Wheel Steering (NWS) and Brakes

Question 1

What does the NWS provide the pilot?

Answer 1

Directional control during:
1) Taxing
2) Parking
3) Takeoff
4) Landing

Question 2

What do the brakes provide the aircraft?

Answer 2

Speed and directional control during ground operations

Question 3

How are rudder pedals links to nose wheel? What does this system consist of?

Answer 3

Mechanically linked
1. Rudder pedals
2. Cable quadrant
3. Spring loaded strut
4. Steering collar

Question 4

What is the Power Brake and Anti-ski Control Valve (PBACV)?

Answer 4

Provides brake pressure boost and anti-skid control functions.

Question 5

What switches give pilot control over PBACV?

Answer 5

1. ANTI-SKID switch
2. TRIM/AIL PWR

Question 6

Which MFD page displays the serviceability of the brakes and the anti-ski?

Answer 6

MFD HYD

Question 7

What does a cyan PARK advisory indicate?

Answer 7

The PARK BRAKE handle is pulled

Question 8

What does a green ON advisory indicate?

Answer 8

The left and/or right brake pedal is depressed

Question 9

What does a green BRAKE OFF indicate?

Answer 9

The the brake system is operational but not active

Question 10

What does a green SKID ON indicate?

Answer 10

Anti-skid normal and anti-skid function is selected.

Question 11

What does full rudder pedal turn the nose wheel through?

Answer 11

11.5 degrees left and right

Question 12

When can the nose wheel be forced to castor up to when differential braking is applied?

Answer 12

60 degrees

Question 13

What are the three modes of braking and what do they mean?

Answer 13

Mode 1 = Anti-skid set to ON and system operates with power braking with anti-ski
Mode 2 = ANTI-SKID set to Off, Power braking without anti-skid
Mode 3 = Automatically selected when normal hydraulic pressure and emergency hydraulic pressure fall below master cylinder pressure OR when TRIM/AIL PWR switch set to off. Higher pedal pressure must be applied.

Question 14

When will hydraulic pressure only be passed to the brakes? Why is this in place?

Answer 14

1) System detects wheel spin
2) 3 seconds have elapsed after the WOW switch has detected touchdown.
- Prevents brake pressure from being applied until the main wheels are operating sufficiently for anti-ski system to operate.

Question 15

When is ANTI-SKID function automatically inhibited?

Answer 15

When speed is < 10 KIAS to allow for full maneuvering on the ground.

Question 16

What is applied automatically on gear retraction?

Answer 16

Limited brake pressure to stop wheels from spinning.

Question 17

How is park brake operated?

Answer 17

Pulling and turning the park brake handle in the front cockpit to the parked and locked position while pressing brake pedals.

Question 18

What must be done with the brakes before engine start?

Answer 18

1. Park brake handle turned to park position
2. Brake pedals pumped several times until they go hard.

Question 19

What does an amber SKID caution mean on the MFD/DWP?

Answer 19

1. Malfunction of ANTI-SKID system
2. ANTI-SKID switch selected to OFF

Question 20

what does amber FAIL mean on MFD HYD?

Answer 20

Built-in test has failed

Question 21

what does an amber SERVO caution on MFD mean?

Answer 21

1. Hydraulic power to wheel brakes and anti-skid is not available
2. TRIM/AIL PWR switch is selected to the OFF position