Systems 2 - AFCS Flashcards
AFCS is short for?
Automatic Flight Control System
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?
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
AFCS 5 subcomponents
- stabilator
- SAS
- Trim
- Flight path stabilation (FPS)
- Flight director
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?
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
What is an inner loop system? And what is different from outer loop system
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
What are the five basic subsystems that comprise AFCS?
Stabilator, Trim, SAS, FPS, and Coupled FD.
What type of Stability is Static associated with, Short or Long Term?
Long Term
The Outer Loop is associated with which subsystem of AFCS?
Trim/FPS.
The FCCs get its P/R/Y information from where?
The EGIs
What are the stabilator functions?
*(SCALP)*
- Streamlines at low airspeeds
- Collective/Pitch coupling
- Angle of incedence decreases with IAS increase
- Lateral to sideslip pitch coupling
- Pitch rate feedback
What are the stabilator Signals?
*(CLAP)*
- Collective position
- Lateral accelerometer
- Airspeed
- Pitch
What is the stabilitor system?
A system that drives a variable Angle of Incedence airfoil
What is the purpose of the stabilator system?
To provide stability in the pitch axis
What is the brains for the stabilator?
FCC #1 and #2
What is the Muscles of the stabilator?
1 and #2 stabilator actuator
Are the actuators in the stabilator eletric or hydraulic driven?
Electric driven by a Jackscrew motor
What is the function of the Position potentiometer
To signal the respective FCC what its stabilator actuator position currently is
Where do the PFD get the stabilator position information from?
Position sensor / Positon transmitter and limit switch assembly
NOTE
Use of the cyclic mounted stabilator slew up switch should be _____ to _____, to minimize cockpit confusion
NOTE
Use of the cyclic mounted stabilator slew up switch should be anounced to the crew, to minimize cockpit confusion
When the stabilator is in Limited Auto Mode, what is the stabilator limited in?
Limited in
- Range of motion
- Speed
What are the four signals used by the FCC’s to position the Stabilator?
Collective Stick Position
Lateral Accelerometers
Airspeed
Pitch rate
What is the purpose of the stabilator?
Enhances handling qualities in the pitch axis in forward flight.
What provides the FCCs with pitch rate information for the Stabilator?
The EGIs.
What are the two cautions and one advisory associated with the Stabilator?
STAB MANUAL MODE
STAB UNLOCKED
STAB DEGRADED
If you lost a P, R or Y signal to a FCC, what would happen to the SAS?
STAB DEG would appear if the other FCC still gets a signal
What AFCS subcomponent enhances turn coordination above 50 KIAS?
SAS
What are the five basic subsystems that comprise AFCS?
Stabilator, Trim, SAS, FPS, and Coupled FD
Dynamic stability is provided by?
SAS
Basic auto pilot functions are provided by?
Trim/FPS
The _____caution indicates the majority of AFCS has shut down.
AFCS FAIL
What does the SAS DEGRADED advisory mean?
The SAS pitch, roll, or yaw channel has disengaged
What does the STAB DEGRADED advisory mean?
The stabilator is in a limited auto mode.
To attempt to clear AFCS fault indications, the pilot can______.
press the illuminated CPTR 1 and/or CPTR 2 button
The collective trim beeper can be used below 50 KIAS to ________?
change the aircraft heading
(True/False) AFCS is considered a basic auto pilot?
TRUE
What is a basic auto pilot?
Attitude hold
What is required for proper SPS operation?
- SAS 1 and/or SAS 2
- TRIM
- FPS
- SAS/BOOST
How does FPS know if you want HDG hold or TURN coorddination?
- 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.
What does the FPS FAIL caut mean?
One or more of the FPS functions has disengaged due to a failure (pitch or roll attitude, heading hold, or turn coordination)
Below 50 knots what is the FPSs function in the P/R/Y axis?
- Pitch: Attitude hold
- Roll: Attitude hold
- Yaw: Heading hold
Above 50 knots what is the FPSs function in the P/R/Y axis?
- Pitch: Attitude Hold. Airspeed Hold is now a function of the flight director.
- Roll: Attitude Hold
- Yaw: Heading Hold /Turn Coordination
