PC21 Autopilot System Flashcards
What are the Auto Flight Control System (AFCS) components in the PC-21?
- Autopilot and Flight Director System (AFDS), also commonly called the autopilot
- Trim Aid Device (TAD)
Does the AFDS operate independently of the TAD?
Yes
What axes does the AFDS control the aircraft?
- Pitch
- Roll
What does the TAD provide?
Automatic rudder trim
What are the AFDS components?
1) Flight Guidance Computer (FGC)
2) Pitch servo
3) Roll servo
4) Mode Control Panel (MCP) in the front and rear cockpits.
How is the autopilot and related servos powered?
From GEN 1 BUS
How is the autopilot engagement/disengagement circuitry powered?
By the BATT BUS
Where is the FGC located?
In the avionics bay
What are the functions of the FGC?
1) Management of dual axis digital autopilot
2) Control and monitoring of the autopilot or FD state
3) Provision of the FD cue and the autopilot related annunciators on the PFD
4) Provision of auto trim
5) Flap compensation
6) Malfunctions signaling through the EICAS
At what pitch and roll angle is the autopilot disengaged?
If pitch angle is > +- 22 deg and angle of bank > 38 deg
At what pitch rate is the pitch servo disengaged?
> +- 4 deg/s
At what roll rate is the roll servo disengaged?
> +-15 deg/s
At what G does the pitch servo disengage?
> 1.8 g or < 0.2 g
How are the pitch and roll servos connected to their respective control surfaces?
Through control cables.
What component allows the pilot to manually overpower the servo in the event of a mechanical jam?
A built in mechanical slip clutch
What engagement/selection keys does the MCP provide?
- AP
- FD
What lateral mode selection keys does the MCP have?
- HDG
- NAV
What vertical mode selection keys does the MCP have?
- ALT
- P/S
- VS
What approach mode keys does the MCP have?
APR
What autopilot related switches are on the control column?
- Pitch and roll trim switch
- TCS
- AP disconnect switch
What is the PCL used for?
- Speed
- Yaw trim
What does the AP disconnect switch on the Control Column do?
- It disengaged the autopilot and cancels all operating flight director modes
- Auto trim function is inhibited and pitch and roll servos are disconnected
What does the TCS switch do?
It disconnects the pitch and roll servos for such time that the TCS is operated.
Where are autopilot control selections, target datum, autopilot status and the flight director cue displayed?
PFD
Where is the flight plan routes and autopilot related cautions and advisories displayed?
MFD
What do green autopilot annunciators on the PFD mean?
Active modes.
What occurs when the autopilot is disengaged ?
- AP flashed in red for 5 seconds then disappears
- Aural tone is present as well.
What is displayed on the top left corner of the HUD when the autopilot is engaged?
Asterisk
What occurs if the autopilot data input is invalid?
All indicators are occulted
What is shown on the left hand side of the AP on the PFD?
Lateral Modes
What is shown on the right hand side of the AP on the PFD?
Vertical modes