NATOPS AFCS

Question 1

The AFCS has 3 major subsystems. What are they?

Answer 1

Stability augmentation system (SAS)

Advanced flight control computer (AFCC)

The stabilator system

Question 2

19 functions of AFCS?

Answer 2

1- Automatic Preflight Check
2- pitch, roll, and yaw stability augmentation 
3- pitch and roll hover augmentation/gust alleviation
4- cyclic, collective and pedal trim
5- blade-fold assist
6- pitch and roll attitude hold
7- heading hold
8- airspeed hold
9- turn coordination
10- maneuvering stability
11- RAD alt
12- BAR alt
13- automatic approach
14- hover coupler
15- crew hover
16- automatic depart
17- diagnostics
18- stabilator control
19- cable angle hover

Question 3

The AFCC has 2 types of control. What are they?

Answer 3

Inner-loop (SAS)

Outer-loop (autopilot)

Question 4

Inner-loop is _________.

Answer 4

Fast in response, limited in authority, and does not move the flight controls

Question 5

The outer-loop provides____________

Answer 5

Long term input by moving the flight controls through their full range of travel (100% authority) at a limited rate of 10% per second

Question 6

ATT caution cube indicates loss of pitch or roll attitude or ________

Answer 6

3° mis-compare between EGIs

Question 7

AFCC uses the _______ to choose between the ___________ for the best source of power.

Answer 7

Voltage sensor relay

AC primary buses

Question 8

What are the 4 inputs to the stab?

Answer 8

Collective position

Lateral acceleration

Airspeed

Pitch Rate

Question 9

How is the stab positioned?

What buses power its movement?

Answer 9

2 electrical jackscrew actuators, acting in series

Each provides 1/2 the input.

DC essential bus and the No. 1 DC primary bus

Question 10

Range of motion for the stab in an actuator failure?

Full up? Full down?

Answer 10

35° if it fails fall down or 30° if it fails full up

Question 11

What is the primary purpose of the Stabilator system?

Answer 11

To eliminate undesirable nose-up attitudes caused by rotor downwash on the horizontal stabilator during transition to a hover and low-speed flight.

Question 12

Can the stabilator fail without illumination of the STABILATOR caution light and associated aural warning tone?

Answer 12

Yes, first indication of a failure will be an uncommanded pitch change.

Question 13

When is the TEST pushbutton for the stab operational?

Answer 13

below 50 KIAS

Question 14

What is the range of motion for the stab?

Answer 14

42* trailing-edge down for hover and low-speed flight (below 30 KIAS) to 10* trailing edge up for cruise and maneuvering flight.