Systems 2 - AFCS

Question 1

AFCS is short for?

Answer 1

Automatic Flight Control System

Question 2

SAS characteristics:

• Dynamic/Static stability?
• Short term/Long term?
• Which axis?
• Inner/Outer loop?
• Slow/Fast reactions?
• Amount of controll? (%)
• What is the brain?
• What is the muscles?

Answer 2

SAS characteristics:

• Dynamic/Static stability?
• Short term/Long term?
• Which axis? - P/R/Y axis
• Inner/Outer loop?
• Slow/Fast reactions?
• Amount of controll? Limited - 2x 5%
• What is the brain? FCC #1 and #2
• What is the muscles? P/R/Y SAS actuators

Question 3

AFCS 5 subcomponents

Answer 3

• stabilator
• SAS
• Trim
• Flight path stabilation (FPS)
• Flight director

Question 4

FPS characteristics:

• Dynamic/Static stability?
• Short term/Long term?
• Which axis?
• Inner/Outer loop?
• Slow/Fast reactions?
• Amount of controll? (%)
• What is the brain?
• What is the muscles?

Answer 4

FPS characteristics:

• Dynamic/Static stability?
• Short term/Long term?
• Which axis? - P/R/Y
• Inner/Outer loop?
• Slow/Fast reactions?
• Amount of controll? Full - 100%
• What is the brain? - FCC #1 and #2
• What is the muscles? - P/R/Y Trim

Question 5

What is an inner loop system? And what is different from outer loop system

Answer 5

A system that can provide changes to the rotorblades without changing the flight control positions

• The outer loop system also makes changes to the rotorblades but at the same time changes the flight control positions

Question 6

What are the five basic subsystems that comprise AFCS?

Answer 6

Stabilator, Trim, SAS, FPS, and Coupled FD.

Question 7

What type of Stability is Static associated with, Short or Long Term?

Answer 7

Long Term

Question 8

The Outer Loop is associated with which subsystem of AFCS?

Answer 8

Trim/FPS.

Question 9

The FCCs get its P/R/Y information from where?

Answer 9

The EGIs

Question 10

What are the stabilator functions?

Answer 10

*(SCALP)*

• Streamlines at low airspeeds
• Collective/Pitch coupling
• Angle of incedence decreases with IAS increase
• Lateral to sideslip pitch coupling
• Pitch rate feedback

Question 11

What are the stabilator Signals?

Answer 11

*(CLAP)*

• Collective position
• Lateral accelerometer
• Airspeed
• Pitch

Question 12

What is the stabilitor system?

Answer 12

A system that drives a variable Angle of Incedence airfoil

Question 13

What is the purpose of the stabilator system?

Answer 13

To provide stability in the pitch axis

Question 14

What is the brains for the stabilator?

Answer 14

FCC #1 and #2

Question 15

What is the Muscles of the stabilator?

Answer 15

1 and #2 stabilator actuator

Question 16

Are the actuators in the stabilator eletric or hydraulic driven?

Answer 16

Electric driven by a Jackscrew motor

Question 17

What is the function of the Position potentiometer

Answer 17

To signal the respective FCC what its stabilator actuator position currently is

Question 18

Where do the PFD get the stabilator position information from?

Answer 18

Position sensor / Positon transmitter and limit switch assembly

Question 19

NOTE

Use of the cyclic mounted stabilator slew up switch should be _____ to _____, to minimize cockpit confusion

Answer 19

NOTE

Use of the cyclic mounted stabilator slew up switch should be anounced to the crew, to minimize cockpit confusion

Question 20

When the stabilator is in Limited Auto Mode, what is the stabilator limited in?

Answer 20

Limited in

• Range of motion
• Speed

Question 21

What are the four signals used by the FCC’s to position the Stabilator?

Answer 21

Collective Stick Position

Lateral Accelerometers

Airspeed

Pitch rate

Question 22

What is the purpose of the stabilator?

Answer 22

Enhances handling qualities in the pitch axis in forward flight.

Question 23

What provides the FCCs with pitch rate information for the Stabilator?

Answer 23

The EGIs.

Question 24

What are the two cautions and one advisory associated with the Stabilator?

Answer 24

STAB MANUAL MODE

STAB UNLOCKED

STAB DEGRADED

Question 25

If you lost a P, R or Y signal to a FCC, what would happen to the SAS?

Answer 25

STAB DEG would appear if the other FCC still gets a signal

Question 26

What AFCS subcomponent enhances turn coordination above 50 KIAS?

Answer 26

SAS

Question 27

What are the five basic subsystems that comprise AFCS?

Answer 27

Stabilator, Trim, SAS, FPS, and Coupled FD

Question 28

Dynamic stability is provided by?

Answer 28

SAS

Question 29

Basic auto pilot functions are provided by?

Answer 29

Trim/FPS

Question 30

The \_\_\_\_\_caution indicates the majority of AFCS has shut down.

Answer 30

AFCS FAIL

Question 31

What does the SAS DEGRADED advisory mean?

Answer 31

The SAS pitch, roll, or yaw channel has disengaged

Question 32

What does the STAB DEGRADED advisory mean?

Answer 32

The stabilator is in a limited auto mode.

Question 33

To attempt to clear AFCS fault indications, the pilot can\_\_\_\_\_\_.

Answer 33

press the illuminated CPTR 1 and/or CPTR 2 button

Question 34

The collective trim beeper can be used below 50 KIAS to \_\_\_\_\_\_\_\_?

Answer 34

change the aircraft heading

Question 35

(True/False) AFCS is considered a basic auto pilot?

Answer 35

TRUE

Question 36

What is a basic auto pilot?

Answer 36

Attitude hold

Question 37

What is required for proper SPS operation?

Answer 37

- SAS 1 and/or SAS 2 - TRIM - FPS - SAS/BOOST

Question 38

How does FPS know if you want HDG hold or TURN coorddination?

Answer 38

- TRIM beeper is actuated in the lateral direciton - TRIM release switch is pressed and roll atittude is greater than 2.5 degrees - About 1⁄2 inch cyclic displacement and a roll attitude of about 1.0°. - Heading hold is automatically re-engaged and turn coordination disengaged upon recovery from the turn when the lateral stick force, roll attitude, and yaw rate are within prescribed limits. - Alternatively, the coupled FD is not engaged, the collective trim beeper may be used to establish a standard rate of turn.

Question 39

What does the FPS FAIL caut mean?

Answer 39

One or more of the FPS functions has disengaged due to a failure (pitch or roll attitude, heading hold, or turn coordination)

Question 40

**Below** 50 knots what is the FPSs function in the P/R/Y axis?

Answer 40

- Pitch: **Attitude hold** - Roll: **Attitude hold** - Yaw: **Heading hold**

Question 41

**Above** 50 knots what is the FPSs function in the P/R/Y axis?

Answer 41

- Pitch: **Attitude Hold. Airspeed Hold is now a function of the flight director.** - Roll: **Attitude Hold** - Yaw: **Heading Hold /Turn Coordination**