AFMS – GFC 500 Autopilot in Piper PA-28 Series 190-02291-07 Rev. 1
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190-02291-07 Rev. 1 AFMS – GFC 500 Autopilot in Piper PA-28 Series
Page i
Garmin International, Inc
Log of Revisions
FAA APPROVED AIRPLANE FLIGHT MANUAL SUPPLEMENT
GFC 500 Autopilot with ESP
Installed in
Piper PA-28-180 / 160 / 150
And
Piper PA-28-181 / 161 / 151
REV
NO.
PAGE NO(S) DESCRIPTION
DATE OF
APPROVAL
FAA APPROVED
1 ALL Original Issue See Cover See Cover
AFMS – GFC 500 Autopilot in Piper PA-28 Series 190-02291-07 Rev. 1
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190-02291-07 Rev. 1 AFMS – GFC 500 Autopilot in Piper PA-28 Series
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Table of Contents
Section 1 – General .................................................................................................... 1-1
USE OF THE SUPPLEMENT ................................................................................................................ 1-1
ABBREVIATIONS AND TERMINOLOGY ............................................................................................. 1-2
INSTALLED EQUIPMENT INTERFACES ............................................................................................. 1-3
INSTALLED FEATURES CHECKLIST ................................................................................................. 1 - 4
Section 2 – Limitations .............................................................................................. 2-1
Section 3 – Emergency Procedures ......................................................................... 3-1
AUTOPILOT MALFUNCTION / PITCH TRIM RUNAWAY .................................................................... 3-1
AUTOPILOT FAILURE / ABNORMAL DISCONNECT ......................................................................... 3-2
PITCH TRIM FAILURE .......................................................................................................................... 3-2
ESP ACTIVATION ................................................................................................................................. 3-2
OVERSPEED PROTECTION (MAXSPD) .............................................................................................. 3-3
UNDERSPEED PROTECTION (MINSPD) ............................................................................................ 3-3
Section 3A – Non-Normal Procedures ...................................................................... 3-5
AUTOPILOT ABNORMAL DISCONNECT ............................................................................................ 3-5
AUTOPILOT PRE-FLIGHT TEST FAIL ................................................................................................. 3-5
MANUAL AUTOPILOT DISCONNECT ................................................................................................. 3-5
LOSS OF NAVIGATION INFORMATION .............................................................................................. 3-5
LOSS OF AIRSPEED DATA ................................................................................................................. 3-6
LOSS OF ALTITUDE DATA .................................................................................................................. 3-6
LOSS OF GPS INFORMATION ............................................................................................................. 3-6
HEADING DATA SOURCE FAILURE ................................................................................................... 3-7
ELEVATOR MISTRIM (AUTOTRIM) ..................................................................................................... 3-7
Section 4 – Normal Procedures ................................................................................ 4-1
GFC 500 POWER UP ............................................................................................................................ 4-1
FLIGHT DIRECTOR / AUTOPILOT NORMAL OPERATING PROCEDURES ..................................... 4-1
VERTICAL MODES ............................................................................................................................... 4-2
VERTICAL SPEED (VS) MODE ......................................................................................................... 4-2
INDICATED AIRSPEED (IAS) MODE ................................................................................................ 4 - 2
ALTITUDE HOLD (ALT) MODE, MANUAL CAPTURE ...................................................................... 4-2
GO AROUND ...................................................................................................................................... 4-2
MANUAL PITCH TRIM WITH AUTOPILOT ENGAGED .................................................................... 4-3
LATERAL MODES ................................................................................................................................. 4-4
HEADING MODE (HDG) .................................................................................................................... 4-4
TRACK MODE (TRK) ......................................................................................................................... 4-4
AFMS – GFC 500 Autopilot in Piper PA-28 Series 190-02291-07 Rev. 1
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NAVIGATION (VOR) ........................................................................................................................... 4-4
NAVIGATION (GPS) ........................................................................................................................... 4-5
APPROACHES ...................................................................................................................................... 4-6
ILS ....................................................................................................................................................... 4-6
LOC (GS out) ...................................................................................................................................... 4-6
GPS Approach (LPV, LNAV/VNAV, LP+V, or LNAV+V) .................................................................... 4-7
GPS Approach (LP, LNAV) ................................................................................................................. 4-7
BC ....................................................................................................................................................... 4-8
VOR Approach .................................................................................................................................... 4-9
DISABLING ESP .................................................................................................................................. 4-10
Section 5 – Performance ........................................................................................... 5-1
Section 6 – Weight and Balance ............................................................................... 6-1
Section 7 – System Description ................................................................................ 7-1
AFCS OVERVIEW ................................................................................................................................. 7-1
AUTOPILOT CONTROL UNIT AND DISPLAY ..................................................................................... 7-4
PREFLIGHT TEST ................................................................................................................................. 7-7
MESSAGES AND ANNUNCIATIONS ................................................................................................... 7 - 7
LIGHTING............................................................................................................................................... 7-8
190-02291-07 Rev. 1 AFMS – GFC 500 Autopilot in Piper PA-28 Series
Page 1–1
SECTION 1 – GENERAL
The information in this supplement is FAA-approved material and must be attached to the Pilot’s Operating
Handbook and FAA Approved Airplane Flight Manual (POH/AFM) when the airplane has been modified by
installation of the Garmin GFC 500 Autopilot system in accordance with Garmin International, Inc. approved data.
The information in this supplement supersedes or adds to the basic POH/AFM only as set forth below. Users of
the manual are advised to always refer to the supplement for possibly superseding information and placarding
applicable to operation of the airplane.
USE OF THE SUPPLEMENT
The following definitions apply to WARNINGS, CAUTIONS and NOTES found throughout the supplement:
Operating procedures, techniques, etc., which may result in personal injury or loss of life if not
carefully followed.
CAUTION
Operating procedures, techniques, etc., which may result in damage to equipment if not
carefully followed.
NOTE
Operating procedures, techniques, etc., which is considered essential to emphasize.
WARNING
AFMS – GFC 500 Autopilot in Piper PA-28 Series 190-02291-07 Rev. 1
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ABBREVIATIONS AND TERMINOLOGY
The following glossary is applicable within the airplane flight manual supplement
AFCS Automatic Flight Control System
AFM Airplane Flight Manual
AFMS Airplane Flight Manual Supplement
AGL Above Ground Level
AHRS Attitude and Heading Reference
System
ALT Altitude
AP Autopilot
APR Approach
ATC Air Traffic Control
BC Back Course Approach
CDI Course Deviation Indicator
DA Decision Altitude
DISC Disconnect
DWG Drawing
ESP Electronic Stability and Protection
FAA Federal Aviation Administration
FAF Final Approach Fix
FD Flight Director
GA Go Around
GFC 500 Garmin Autopilot
GMC 507 Autopilot Mode Control Panel
GNSS Global Navigation Satellite System
GPS Global Positioning System
GS Glideslope
GSA Garmin Servo Actuator
HDG AFCS heading mode
IAS Indicated Airspeed
ILS Instrument Landing System
INT Interrupt
KIAS Knots Indicated Airspeed
KT Knot
LNAV Lateral Navigation
LNAV+V Lateral Navigation with Advisory
Vertical Guidance
LNAV/VNAV Lateral Navigation / Vertical
Navigation Approach
LOC Localizer (no glideslope available)
LP Localizer Performance
LP+V Localizer Performance with Advisory
Vertical Guidance
LPV Localizer Performance with Vertical
Guidance
LVL Level
MDA Minimum Descent Altitude
MPH Miles per Hour
PFT Preflight Test
POH Pilot’s Operating Handbook
STC Supplemental Type Certificate
TO Takeoff
TRK Track
VHF Very High Frequency
VOR VHF Omni-directional Range
VS Vertical Speed
190-02291-07 Rev. 1 AFMS – GFC 500 Autopilot in Piper PA-28 Series
Page 1–3
INSTALLED EQUIPMENT INTERFACES
The following is the list of installed equipment and functions associated with the GFC 500 Autopilot installation in
this airplane.
Table 1-1: Table of Installed Equipment Interfaces
DEVICE TYPE Manufacturer / Model
If not installed, note N/A
Additional Information
GPS Navigator #1
Is Navigator #1 interfaced to GFC 500?
YES NO
VHF Nav Radio #1
Is VHF Nav Radio #1 interfaced to GFC 500?
YES NO
VHF Nav Radio #2
Pitch Trim Servo
AFMS – GFC 500 Autopilot in Piper PA-28 Series 190-02291-07 Rev. 1
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INSTALLED FEATURES CHECKLIST
The checked autopilot modes and features are available on this aircraft.
Basic AP Features
Flight Director
Electric Pitch Trim
Overspeed Protection
Underspeed Protection
Vertical Autopilot Modes
Pitch (PIT)
Level (Zero vertical speed)
Go Around (GA)
Altitude Hold
Vertical Speed
Altitude Capture via Altitude Preselect
Indicated Airspeed (IAS)
GPS Approach Glidepath
ILS Glideslope
Electronic Stability and Protection
Pitch/Roll Attitude
High Speed Protection
Low Speed Protection
Lateral Autopilot Modes
Roll (ROL)
Level (Wings Level)
Go Around (GA)
Heading
Track
GPS Navigation
VHF Navigation
Approach Mode
GPS
VOR/LOC
190-02291-07 Rev. 1 AFMS – GFC 500 Autopilot in Piper PA-28 Series
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SECTION 2 – LIMITATIONS
The Garmin G5 Electronic Flight Instrument Pilot’s Guide for Certified Aircraft, part number 190-01112-12 Rev B
(or later approved revisions), must be immediately available to the flight crew.
This AFMS is applicable to the software versions shown below:
Software Item
Software Version
(or later FAA Approved version for this STC)
G5 Software Version 5.0
A pilot must be seated in the left pilot’s seat, with seatbelt fastened, during all autopilot operations.
Do not use autopilot during takeoff and landing.
The GFC 500 AFCS preflight test must complete successfully prior to use of the autopilot, flight director or manual
electric trim.
The maximum fuel imbalance with the autopilot engaged is 10 gallons.
The autopilot must be disengaged below 200 feet AGL during approach operations and below 800 feet AGL
during all other operations.
The GFC 500 autopilot is approved for Category 1 precision approaches and non-precision approaches only.
Autopilot Engagement Speed
Minimum 65 KIAS (75 MPH)
Maximum 140 KIAS (160 MPH)
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SECTION 3 – EMERGENCY PROCEDURES
Some emergency situations require immediate memorized corrective action. These steps are printed in bold in the
emergency procedures and should be accomplished without the aid of the checklist.
AUTOPILOT MALFUNCTION / PITCH TRIM RUNAWAY
If the airplane deviates unexpectedly from the planned flight path:
1. Control Wheel ............................................................................................................ GRIP FIRMLY
2. AP DISC / TRIM INT Button ............................................................................. PRESS AND HOLD
(Be prepared for high elevator control forces)
3. Aircraft Attitude ....................................................... MAINTAIN / REGAIN AIRCRAFT CONTROL
NOTE
Do not release the AP DISC / TRIM INT Button until after pulling the AUTOPILOT Circuit Breaker.
4. Elevator Trim ........................................................ RE-TRIM if necessary using Elevator Tab Wheel
5. AUTOPILOT Circuit Breaker ..................................................................................................... PULL
NOTE
Pulling the AUTOPILOT circuit breaker will render the autopilot and ESP inoperative.
6. AP DISC / TRIM INT Button .............................................................................................. RELEASE
In flight, do not overpower the autopilot. The trim will operate in the direction opposing the
overpower force, which will result in large out-of-trim forces.
Do not attempt to re-engage the autopilot or use manual electric pitch trim until the cause of the
malfunction has been corrected.
WARNING
AFMS – GFC 500 Autopilot in Piper PA-28 Series 190-02291-07 Rev. 1
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AUTOPILOT FAILURE / ABNORMAL DISCONNECT
(Red AP in autopilot status box on display, continuous aural disconnect tone.)
1. AP DISC / TRIM INT Button or G5 Knob .................................................... PRESS AND RELEASE
(to cancel disconnect tone)
2. Aircraft Attitude ........................................................... MAINTAIN / REGAIN AIRCRAFT CONTROL
NOTE
The autopilot disconnect may be accompanied by a red AFCS in the autopilot status box,
indicating the automatic flight control system has failed. The flight director will not be available
and the autopilot cannot be re-engaged with this annunciation present.
If the disconnect is accompanied by an amber AP with a red X, the autopilot will not be available
however the flight director will still be functional.
In the event of a GMC failure, pressing the G5 knob will acknowledge the disconnect tone.
PITCH TRIM FAILURE
(Red PTRIM on G5 display.)
This failure will only occur if the optional pitch trim servo is installed.
1. Indicates a failure of the pitch trim servo.
2. Control Wheel ............................................................................................................. GRIP FIRMLY
3. AP DISC / TRIM INT Button .......................................................................... PRESS and RELEASE
(Be prepared for high elevator control forces)
4. Elevator Trim ...................................................... AS REQUIRED USING ELEVATOR TAB WHEEL
NOTE
The autopilot may be re-engaged. Refer to the normal procedures section of this AFMS,
MANUAL PITCH TRIM WITH AUTOPILOT ENGAGED.
ESP ACTIVATION
1. Power ........................................................................................................................ AS REQUIRED
2. Aircraft Attitude ....................................................... MAINTAIN / REGAIN AIRCRAFT CONTROL
NOTE
If ESP is active for approximately 10 seconds, the autopilot will automatically engage in LVL
mode, an aural ‘ENGAGING AUTOPILOT’ will be played, (or a Sonalert tone will sound for
installations without a supported audio panel) and the autopilot will roll the wings level and fly at
zero-vertical speed. Refer to Section 7, System Description for further information.
ESP will be disabled by pressing and holding the AP DISC / TRIM INT button. Releasing the
button will allow ESP to function.
190-02291-07 Rev. 1 AFMS – GFC 500 Autopilot in Piper PA-28 Series
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OVERSPEED PROTECTION (MAXSPD)
(MAXSPD displayed on G5, AIRSPEED – AIRSPEED Aural sounds.)
1. Power.................................................................................................................................. REDUCE
2. Aircraft Attitude and Altitude ......................................................................................... MONITOR
After overspeed condition is corrected:
3. Autopilot .......................................RESELECT VERTICAL AND LATERAL MODES (if necessary)
4. Power ............................................................................................................. ADJUST as necessary
NOTE
Autopilot Overspeed Protection Mode provides a pitch up command to maintain 140 KIAS (160
MPH).
UNDERSPEED PROTECTION (MINSPD)
(MINSPD displayed on G5, AIRSPEED – AIRSPEED Aural sounds.)
1. Power.................................. INCREASE POWER AS REQUIRED TO CORRECT UNDERSPEED
2. Aircraft Attitude and Altitude ......................................................................................... MONITOR
After underspeed condition is corrected:
3. Autopilot .........................................RESELECT VERTICAL AND LATERAL MODES (if necessary)
4. Power ............................................................................................................. ADJUST as necessary
NOTE
Autopilot Underspeed Protection Mode provides a pitch down command to maintain 65 KIAS (75
MPH).
AFMS – GFC 500 Autopilot in Piper PA-28 Series 190-02291-07 Rev. 1
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SECTION 3A – NON-NORMAL PROCEDURES
AUTOPILOT ABNORMAL DISCONNECT
(Red AP in the G5 autopilot status box, continuous aural disconnect tone.)
1. AP DISC / TRIM INT Button .........................................................................PRESS AND RELEASE
(to cancel disconnect tone)
2. Aircraft Attitude ........................................................... MAINTAIN / REGAIN AIRCRAFT CONTROL
NOTE
The autopilot disconnect may be accompanied by a red AFCS in the autopilot status box,
indicating the automatic flight control system has failed. The flight director will not be available
and the autopilot cannot be re-engaged with this annunciation present.
If the disconnect is accompanied by an amber AP with a red X, the autopilot will not be available
however the flight director will still be functional.
AUTOPILOT PRE-FLIGHT TEST FAIL
(Amber AP with a red X in G5 autopilot status box.)
1. Indicates the AFCS system failed the automatic Pre-Flight test. The autopilot, ESP, and electric
elevator trim are inoperative. Flight director will still function.
MANUAL AUTOPILOT DISCONNECT
If necessary, the autopilot may be manually disconnected using any one of the following methods:
1. AP DISC / TRIM INT Button .......................................................................... PRESS and RELEASE
(Pilot’s control wheel)
2. AP Key ................................................................................................................................... PRESS
3. Pitch Trim Switch ............................................................................................................. ACTIVATE
4. AUTOPILOT Circuit Breaker ..................................................................................................... PULL
LOSS OF NAVIGATION INFORMATION
(Amber GPS, VOR, LOC, or BC flashes for 10 seconds on G5.)
NOTE
If a navigation signal is lost while the autopilot is tracking it, the autopilot will roll the aircraft
wings level and default to roll mode (ROL).
1. GMC 507 Mode Panel ............................................. SELECT HDG mode and SET desired heading
2. NAV Source ......................................................................................... SELECT a valid NAV source
3. NAV Key ................................................................................................................................. PRESS
If on an instrument approach at the time the navigation signal is lost:
4. Missed Approach Procedure .................................................................... EXECUTE (as applicable)
AFMS – GFC 500 Autopilot in Piper PA-28 Series 190-02291-07 Rev. 1
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LOSS OF AIRSPEED DATA
(Red X through airspeed tape on the G5 display, amber AP with a red X in autopilot status box.)
NOTE
If airspeed data is lost while the autopilot is tracking airspeed, the flight director will default to
pitch mode (PIT).
1. AP DISC / TRIM INT Button ........................................................................ PRESS AND RELEASE
(to cancel disconnect tone)
2. Aircraft Attitude ........................................................... MAINTAIN / REGAIN AIRCRAFT CONTROL
3. Manual Elevator Trim ............................................................................................. TRIM as required
NOTE
The autopilot cannot be re-engaged. The flight director is available however IAS mode cannot
be selected. Loss of airspeed will be accompanied by a red PTRIM indication on the G5 (if a
pitch trim servo is installed).
LOSS OF ALTITUDE DATA
(Red X through altitude tape on the G5 display.)
NOTE
If altitude data is lost while the autopilot is tracking altitude, the autopilot will default to pitch mode
(PIT).
1. Autopilot .......................................................................................... SELECT different vertical mode
LOSS OF GPS INFORMATION
(GPS position information is lost to the autopilot.)
NOTE
If GPS position data is lost while the autopilot is tracking a GPS, VOR, LOC or BC course, the
autopilot will default to roll mode (ROL). The autopilot will default to pitch mode if GPS
information is lost while tracking an ILS. The autopilot uses GPS aiding in VOR, LOC and BC
modes.
1. Autopilot ................................................ SELECT different lateral and vertical mode (as necessary)
If on an instrument approach:
AP DISC / TRIM INT button ................................... PRESS, Continue the approach manually
Or
Missed Approach Procedure .......................................................... EXECUTE (as applicable)
190-02291-07 Rev. 1 AFMS – GFC 500 Autopilot in Piper PA-28 Series
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HEADING DATA SOURCE FAILURE
Without a heading source to the navigator, the following features will not operate:
GPSS will not be provided to the autopilot for heading legs.
Map cannot be oriented to Heading Up.
Track information will be displayed on the G5.
1. Autopilot ............................................................................................ SELECT different lateral mode
ELEVATOR MISTRIM (AUTOTRIM)
(Amber TRIM UP or TRIM DOWN displayed on the G5.)
Indicates a mistrim of the elevator while the autopilot is engaged. If a pitch trim servo is not installed, refer to the
normal procedures section of this AFMS, MANUAL PITCH TRIM WITH AUTOPILOT ENGAGED. If a pitch trim
servo is installed, the autopilot will normally trim the airplane as required. However, during rapid acceleration,
deceleration, configuration changes, or near either end of the elevator trim limits, momentary illumination of this
message may occur. If the autopilot is disconnected while this message is displayed, high elevator control
forces are possible.
Do not attempt to overpower the autopilot in the event of a pitch mistrim. The autopilot servo
will oppose pilot input and will cause pitch trim to run opposite the direction of pilot input. This
will lead to a significant out-of-trim condition, resulting in large control wheel force when
disengaging the autopilot.
If a pitch trim servo is not installed:
1. Refer to the normal procedures section of this AFMS, MANUAL PITCH TRIM WITH AUTOPILOT
ENGAGED.
If a pitch trim servo is installed:
NOTE
Momentary display of the TRIM UP or TRIM DOWN message during configuration changes or
large airspeed changes is normal.
1. Control Wheel ............................................................................................................. GRIP FIRMLY
Be prepared for significant sustained control forces in the direction of the mistrim annunciation.
For example, TRIM DOWN indicates nose down control wheel force will be required upon
autopilot disconnect.
2. AP DISC / TRIM INT Button .........................................................................PRESS AND RELEASE
3. Manual Elevator Trim ....................................................................................... RE-TRIM as required
Electric pitch trim should be considered inoperative until the cause of the mistrim has been investigated and
corrected.
WARNING
WARNING
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SECTION 4 – NORMAL PROCEDURES
GFC 500 POWER UP
During the preflight test the G5 will display PFT in the autopilot status box. The autopilot disconnect tone sounds
at the completion of the preflight test. When the GFC 500 passes preflight test, PFT will be removed from the
autopilot status box.
FLIGHT DIRECTOR / AUTOPILOT NORMAL OPERATING PROCEDURES
Autopilot/Flight Director mode annunciations are displayed at the top of the G5 Electronic Flight Instrument.
Green text indicates active autopilot/flight director modes. Armed modes are indicated in white text. Normal
mode transitions will flash inverse video for 10 seconds before becoming steady. Abnormal mode transitions will
flash for 10 seconds in amber text before the default mode is annunciated as the active mode in green text.
Default autopilot/flight director modes are Roll (ROL) and Pitch (PIT) modes.
The autopilot status box displays the autopilot engagement status as well as armed and active flight director
modes.
Autopilot Engagement with Flight Director Off — Upon engagement, the autopilot will be set to hold the
current attitude of the airplane if the flight director was not previously on. In this case, ‘ROL’ and ‘PIT’ will be
annunciated.
Autopilot Engagement with Flight Director On — If the flight director is on, the autopilot will smoothly pitch and
roll the airplane to capture the FD command bars. The prior flight director modes remain unchanged.
Autopilot Disengagement — The most common way to disconnect the autopilot is to press and release the AP
DISC / TRIM INT button located on the control yoke. An autopilot disconnect tone will sound and an amber AP
will be annunciated on the G5 autopilot status box. Other ways to disconnect the autopilot include:
– Pressing the AP Key on the GMC 507 Mode Controller
– Operating the Electric Pitch Trim Switch (located on the control wheel)
– Pulling the AUTOPILOT circuit breaker
In the event of unexpected autopilot behavior, press and holding the AP DISC / TRIM INT button will disconnect
the autopilot and remove all power to the servos.
AFMS – GFC 500 Autopilot in Piper PA-28 Series 190-02291-07 Rev. 1
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VERTICAL MODES
VERTICAL SPEED (VS) MODE
1. Altitude Preselect ......................................................................................... SET to Desired Altitude
2. Press VS Key, autopilot synchronizes to the airplane’s current vertical speed.
3. Vertical Speed Reference ............................................................... ADJUST using UP / DN Wheel
4. Green ALT ........................................................................................ VERIFY Upon Altitude Capture
INDICATED AIRSPEED (IAS) MODE
1. Altitude Preselect ......................................................................................... SET to Desired Altitude
2. Press IAS Key, autopilot synchronizes to the airplane’s current indicated airspeed.
3. AIRSPEED Reference ...................................................................... ADJUST using UP / DN Wheel
4. Adjust throttle as required ................................................................... INCREASE POWER to climb
DECREASE POWER to descend
5. Green ALT ........................................................................................ VERIFY Upon Altitude Capture
ALTITUDE HOLD (ALT) MODE, MANUAL CAPTURE
1. When at the desired altitude .................................................................................... PRESS ALT key
The autopilot will hold the altitude at which the ALT key was pressed.
If climbing or descending at a high rate when the ALT key is pressed, the airplane will overshoot
the reference altitude and then return to it. The amount of overshoot will depend on the vertical
speed when the ALT key is pressed.
The altitude reference is displayed in the autopilot status box. The reference may be changed by
+/- 200 FT using the UP / DN wheel.
GO AROUND
1. GO AROUND button ....................................................................... PRESS – Verify GA / GA on G5
autopilot will not disengage
2. Autopilot (if engaged) ............... VERIFY airplane pitches up following flight director command bars
3. Power ........................................................................................................ APPLY Go Around power
4. GMC 507 Mode Panel .................................... PRESS NAV to couple to selected navigation source
OR
PRESS HDG to Fly ATC Assigned Missed Approach Heading
5. Altitude Preselect .................................................................................................................. VERIFY
Set to appropriate altitude.
NOTE
The pilot is responsible for initial missed approach guidance in accordance with published
procedure. When the GA button is pressed the Flight Director command bars will command go-
around pitch attitude and wings level. The pilot must select the CDI to the appropriate navigation
source and select the desired lateral and vertical flight director modes.
190-02291-07 Rev. 1 AFMS – GFC 500 Autopilot in Piper PA-28 Series
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MANUAL PITCH TRIM WITH AUTOPILOT ENGAGED
(Amber TRIM UP or TRIM DOWN displayed on G5.)
If the aircraft is not equipped with a pitch trim servo, the pilot must manually adjust the pitch trim when airspeed and
aircraft configuration changes are made. A message will be displayed on the G5 display to indicate the pitch servo
is holding sustained force, and the pilot must manually trim the aircraft.
1. If TRIM UP message is displayed ........................................................... MANUALLY TRIM nose up
2. If TRIM DOWN message is displayed ............................................... MANUALLY TRIM nose down
AFMS – GFC 500 Autopilot in Piper PA-28 Series 190-02291-07 Rev. 1
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LATERAL MODES
HEADING MODE (HDG)
1. HDG Key ................................................................................................................................ PRESS
The autopilot will turn the airplane in the direction of the heading bug.
2. HDG/TRK Knob ......................................................... Rotate to set heading bug to desired heading.
NOTE
If heading bug is reset too quickly, the airplane could turn in the opposite direction as the heading
bug’s movement.
3. When the airplane reaches the heading bug, the autopilot will roll the wings level to track the
reference.
TRACK MODE (TRK)
1. TRK Key ................................................................................................................................. PRESS
The autopilot will turn the airplane in the direction of the track bug.
2. HDG/TRK Knob ................................................................... Rotate to set track bug to desired track.
NOTE
If track bug is reset too quickly, the airplane could turn in the opposite direction as the track bug’s
movement.
3. When the airplane reaches the track bug, the autopilot will roll the wings level to track the reference.
NAVIGATION (VOR)
1. Navigation Source. ................................................................................. SELECT CDI to VHF NAV
Tune and identify the station frequency.
2. Course Pointer ............................................................................... SET CDI to the Desired Course
3. Intercept Heading ............................................................ ESTABLISH in HDG, TRK or ROL mode
4. NAV Key ................................................................................................................................. PRESS
NOTE
If the Course Deviation Indicator (CDI) is greater than one dot from center, the autopilot will arm
the VOR mode. The pilot must ensure that the current heading will result in a capture of the
selected course. If the CDI is one dot or less from center, the autopilot will enter the capture
mode when the NAV key is pressed.
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NAVIGATION (GPS)
1. Navigation Source ............................................................................................ SELECT CDI to GPS
2. Waypoint .......................................................................................... SELECT on Navigation Source
3. Course Pointer ..................................................................... VERIFY CDI set to the Desired Course
4. Intercept Heading ........................................................................ ESTABLISH in HDG or ROL mode
5. NAV Key ................................................................................................................................. PRESS
NOTE
If the Course Deviation Indicator (CDI) is greater than one dot from center, the autopilot will arm
the GPS mode. The pilot must ensure that the current heading will result in a capture of the
selected course. If the CDI is one dot or less from center, the autopilot will enter the capture mode
when the NAV key is pressed.
AFMS – GFC 500 Autopilot in Piper PA-28 Series 190-02291-07 Rev. 1
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APPROACHES
ILS
1. Navigation Source. .................................................................................... SELECT CDI to VHF Nav
Tune and Identify an ILS station frequency.
2. CDI ............................................................................................................. SET to front LOC course
3. Ensure that the current heading will result in a capture of the selected course.
4. Press APR Key ................................................................................. VERIFY LOC and GS ARMED
5. Verify ............................................................................ Airplane Captures and Tracks LOC and GS
6. Set Missed Approach Altitude in Altitude preselect.
7. At Decision Altitude (DA),
AP DISC / TRIM INT button .......................... PRESS, Continue visually for a normal landing
Or
GO AROUND (GA) button .............................. PRESS, Execute Missed Approach Procedure
Apply GA power.
NOTE
Pressing the GA button will not disconnect the autopilot. Select NAV or HDG mode to fly the
missed approach procedure.
If the Course Deviation Indicator (CDI) is greater than half scale deflection, the autopilot will arm
the LOC mode. The pilot must ensure that the current heading will result in a capture of the
selected course. If the CDI is within half scale deflection, the autopilot will enter the capture
mode when the APR key is pressed.
When the selected navigation source is an ILS, glideslope coupling is automatically armed when
the APR key is pressed. The glideslope cannot be captured until the localizer is captured. The
autopilot can capture the glideslope from above or below the glideslope.
LOC (GS out)
1. Navigation Source ..................................................................................... SELECT CDI to VHF Nav
Tune and Identify an ILS station frequency.
2. Course Pointer ........................................................................................... SET to front LOC course
3. Ensure that the current heading will result in a capture of the selected course.
4. Press NAV Key .............................................................................................. VERIFY LOC ARMED
5. Verify ............................................................................. Airplane Captures and Tracks LOC Course
6. Once airplane is in ALT mode inbound to the FAF, set the altitude preselect to the next required
step down altitude. Use VS mode to descend airplane along the vertical step downs and to the
MDA.
7. When in ALT mode at the MDA, set missed approach altitude in the altitude preselect.
8. At Missed Approach Point,
AP DISC / TRIM INT button .......................... PRESS, Continue visually for a normal landing
190-02291-07 Rev. 1 AFMS – GFC 500 Autopilot in Piper PA-28 Series
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Or
GO AROUND (GA) button .............................. PRESS, Execute Missed Approach Procedure
Apply GA power.
Set missed approach altitude in the altitude preselect.
NOTE
Pressing the GA button will not disconnect the autopilot. Select NAV or HDG mode to fly the
missed approach procedure.
GPS Approach (LPV, LNAV/VNAV, LP+V, or LNAV+V)
1. Navigation Source ............................................................................................ SELECT CDI to GPS
2. Course Pointer ..................................................................... VERIFY CDI set to the Desired Course
3. Ensure that the current heading will result in a capture of the selected course.
4. Press APR Key ................................................................................. VERIFY GPS and GP ARMED
5. Verify ............................................................................ Airplane Captures and Tracks GPS and GP
6. Press ALT Key to level off at the MDA for a LP+V or LNAV+V approach
7. At DA (LPV or LNAV/VNAV approach), or MDA and Missed Approach Point (LP+V or LNAV+V)
AP DISC / TRIM INT button .......................... PRESS, Continue visually for a normal landing
Or
GO AROUND (GA) button .............................. PRESS, Execute Missed Approach Procedure
Apply GA power.
Set missed approach altitude in the altitude preselect.
NOTE
Pressing the GA button will not disconnect the autopilot. Select NAV or HDG mode to fly the
missed approach procedure.
GPS Approach (LP, LNAV)
1. Navigation Source ..................................................................................... SELECT GPS on the CDI
2. Course Pointer .................................................................... VERIFY CDI set on the Desired Course
3. Ensure that the current heading will result in a capture of the selected course.
4. Press NAV Key .............................................................................................. VERIFY GPS ARMED
5. Verify ............................................................................. Airplane Captures and Tracks GPS Course
6. Once airplane is in ALT mode inbound to the FAF, set the altitude preselect to the next required
step down altitude. Use VS mode to descend airplane along the vertical step downs and to the
MDA.
7. When in ALT mode at the MDA, set missed approach altitude in the altitude preselect.
8. At Missed Approach Point,
AP DISC / TRIM INT button .......................... PRESS, Continue visually for a normal landing
Or
AFMS – GFC 500 Autopilot in Piper PA-28 Series 190-02291-07 Rev. 1
Page 4–8
GO AROUND (GA) button .............................. PRESS, Execute Missed Approach Procedure
Apply GA power.
Set missed approach altitude in the altitude preselect.
NOTE
Pressing the GA button will not disconnect the autopilot. Select NAV or HDG mode to fly the
missed approach procedure.
BC
1. Navigation Source. .................................................................................... SELECT CDI to VHF Nav
Tune and Identify an ILS station frequency
2. Course Pointer .................................................................................. SET CDI to LOC Front Course
3. Ensure that the current heading will result in a capture of the selected course.
4. Press NAV Key ................................................................................................. VERIFY BC ARMED
(when heading is within 75 degrees of BC course)
5. Verify ............................................................................... Airplane Captures and Tracks BC Course
6. Once airplane is in ALT mode inbound to the FAF, set the altitude preselect to the next required
step down altitude. Use VS mode to descend airplane along the vertical step downs and to the
MDA.
7. When in ALT mode at the MDA, set missed approach altitude in the altitude preselect.
8. At Missed Approach Point:
AP DISC / TRIM INT button .......................... PRESS, Continue visually for a normal landing
Or
GO AROUND (GA) button .............................. PRESS, Execute Missed Approach Procedure
Apply GA power.
Set missed approach altitude in the altitude preselect.
NOTE
Pressing the GA button will not disconnect the autopilot. Select NAV or HDG mode to fly the
missed approach procedure.
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VOR Approach
1. Navigation Source. .................................................................................... SELECT CDI to VHF Nav
Tune and identify the station frequency
2. Course Pointer ................................................................................. SET CDI to the Desired Course
3. Ensure that the current heading will result in a capture of the selected course.
4. Press NAV Key .............................................................................................. VERIFY VOR ARMED
5. Verify ............................................................................. Airplane Captures and Tracks VOR Course
6. Once airplane is in ALT mode inbound to the FAF, set the altitude preselect to the next required
step down altitude. Use VS mode to descend airplane along the vertical step downs and to the
MDA.
7. When in ALT mode at the MDA, set missed approach altitude in the altitude preselect.
8. At Missed Approach Point:
AP DISC / TRIM INT button .......................... PRESS, Continue visually for a normal landing
Or
GO AROUND (GA) button .............................. PRESS, Execute Missed Approach Procedure
Apply GA power.
Set missed approach altitude in the altitude preselect.
NOTE
Pressing the GA button will not disconnect the autopilot. Select NAV or HDG mode to fly the
missed approach procedure.
AFMS – GFC 500 Autopilot in Piper PA-28 Series 190-02291-07 Rev. 1
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DISABLING ESP
ESP can be disabled on the G5 attitude indicator with the following procedure. ESP will default to “Enabled” on
the next power cycle.
1. G5 Knob. ................................................................................................................................ PRESS
2. ESP ...................................................................................................................................... SELECT
3. G5 Knob ................................................................................................................................. PRESS
NOTE
ESP can also be temporarily disabled by pressing and holding the AP DISC / TRIM INT button.
190-02291-07 Rev. 1 AFMS – GFC 500 Autopilot in Piper PA-28 Series
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SECTION 5 – PERFORMANCE
No Change.
AFMS – GFC 500 Autopilot in Piper PA-28 Series 190-02291-07 Rev. 1
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190-02291-07 Rev. 1 AFMS – GFC 500 Autopilot in Piper PA-28 Series
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SECTION 6 – WEIGHT AND BALANCE
No change to loading information. Refer to current weight and balance report and equipment list for changes to
empty weight/moment and installed equipment.
AFMS – GFC 500 Autopilot in Piper PA-28 Series 190-02291-07 Rev. 1
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190-02291-07 Rev. 1 AFMS – GFC 500 Autopilot in Piper PA-28 Series
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SECTION 7 – SYSTEM DESCRIPTION
AFCS OVERVIEW
The GFC 500 is a digital Automatic Flight Control System (AFCS). It is a two-axis autopilot and flight director
system which provides the pilot with the following features:
G5 Outputs to Autopilot — The G5 flight instrument provides attitude, rate, and acceleration information to the
servos. Additionally, indicated airspeed, vertical speed, pressure altitude and GPS information are sent to the
autopilot for mode control.
Flight Director (FD) — The flight director processing occurs in the G5 instrument. Selected modes for the flight
director are displayed on the G5 autopilot status box.
The flight director provides:
Command Bars showing pitch/roll guidance
Vertical / lateral mode selection and processing
Autopilot (AP) — Autopilot operation occurs within the pitch, roll, and optional pitch trim servo. It also provides
servo monitoring, and automatic flight control in response to flight director steering commands, attitude and rate
information, and airspeed.
Optional Electric Pitch Trim — The pitch trim servo provides manual electric pitch trim capability when the
autopilot is not engaged. The trim servo provides automatic pitch trim when the autopilot is engaged and the
airplane is in the air. Automatic trim functionality is disabled on the ground.
GMC 507 — Pilot commands to the autopilot and flight director are entered through the GMC 507 autopilot mode
panel. The GMC 507 contains internal sensors which calculate the aircraft attitude, attitude rate and
accelerations. These inertial sensors are completely independent from the sensors within the G5 and the rest of
the autopilot system, and are not used for the flight director, autopilot, trim or ESP functions. They are used
solely to provide independent monitoring of the GFC 500.
Airspeed and Altitude Information — The GFC 500 requires airspeed and altitude information from the G5
instrument.
Other components of the AFCS include the GSA 28 pitch, roll, and optional pitch trim servo that also contain
autopilot processors, control wheel mounted elevator trim switch (if trim servo is installed), control wheel mounted
autopilot disconnect and trim interrupt button (AP DISC / TRIM INT), and a Go-Around (GA) button.
Underspeed Protection (USP) — The GFC 500 will provide Underspeed Protection when the autopilot is
engaged.
When the minimum airspeed of 65 KIAS (75 MPH) is reached, a visual MINSPD message will appear above the
airspeed tape and the autopilot will lower the nose to maintain 65 KIAS (75 MPH). An aural “AIRSPEED,
AIRSPEED” voice alert will sound for installations connected to an audio panel.
Underspeed Protection is inhibited when the airspeed exceeds 70 KIAS (80 MPH).
Overspeed Protection (OSP) — The GFC 500 will provide Overspeed Protection when the autopilot is engaged.
When the maximum airspeed of 140 KIAS (160 MPH) is reached, visual MAXSPD message will appear above the
airspeed tape and the autopilot will raise the nose of the aircraft to avoid exceeding 140 KIAS (160 MPH). An
aural “AIRSPEED, AIRSPEED” voice alert will sound for installat
ions connected to an audio panel.
Overspeed Protection is inhibited when the airspeed is below 135 KIAS (155 MPH).
Coupled Go-Around — Pressing the GA button will not disengage the autopilot. Instead, the autopilot will
attempt to capture and track the flight director command bars. If insufficient airplane performance is available to
follow the commands, the autopilot will enter Underspeed Protection mode at the minimum airspeed.
Electronic Stability and Protection (ESP) — The GFC 500 will provide Electronic Stability and Protection when
the autopilot is not engaged.
AFMS – GFC 500 Autopilot in Piper PA-28 Series 190-02291-07 Rev. 1
Page 7–2
Electronic Stability and Protection (ESP) uses the autopilot servos to assist the pilot in maintaining the airplane in
a safe flight condition within the airplane’s normal pitch, roll and airspeed envelopes.
Electronic Stability and Protection is activated when the pilot allows the airplane to exceed one or more conditions
beyond normal flight as defined below:
Pitch attitude beyond normal flight (+20°, -15°)
Roll attitude beyond normal flight (45°)
High airspeed beyond normal flight (above V
NE
+ 1 KIAS [1 MPH])
Low airspeed below normal flight (below V
s
+ 5 KIAS [5 MPH])
ESP requires:
Pitch and Roll servos are installed and functioning
Autopilot not engaged
The GPS altitude above ground is more than 200 feet (for low airspeed mode)
Aircraft is within the autopilot engagement envelope (+/-50° in pitch and +/-75° in roll)
Protection for excessive Pitch, Roll, and Airspeed is provided when the limit thresholds are first exceeded, which
engages the appropriate servo in ESP mode at a nominal torque level to bring the airplane back within the normal
flight envelope. If the airplane deviates further from the normal flight envelope, the servo torque will increase
until the maximum torque level is reached in an attempt to return the airplane into the normal flight envelope.
Once the airplane returns to within the normal flight envelope, ESP will deactivate the autopilot servos.
When the normal flight envelope thresholds have been exceeded for more than 10 seconds, ESP Autolevel Mode
is activated. Autolevel Mode engages the autopilot to bring the airplane back into straight and level flight based
on 0° roll angle and 0 FPM vertical speed. An aural, “ENGAGING AUTOPILOT” (or a Sonalert tone), sounds
and the Flight Director mode annunciation will indicate LVL for the pitch and roll modes.
Any time an ESP mode is active, the pilot can interrupt ESP by using the Autopilot Disconnect (AP DISC / TRIM
INT) switch, or simply override ESP by overpowering the autopilot servos. The pilot may also disable ESP
through the G5 menu.
The engagement and disengagement attitude limits are displayed with double hash marks on the roll indicator
depending on the airplane attitude and whether or not ESP is active in roll. When ESP is inactive (roll attitude
within nominal limits) only the engagement limit indications are displayed in order to reduce clutter on the roll
indicator.
Display symbology implemented for ESP is illustrated in the following figures.
190-02291-07 Rev. 1 AFMS – GFC 500 Autopilot in Piper PA-28 Series
Page 7–3
Figure 7-1: Nominal Roll Attitude ESP Engagement Limit Indications
Once ESP becomes active in roll, the engagement limit indication that was crossed (either Left or Right) will move
to the lower disengagement limit indication. The opposite roll limit remains at the engagement limit.
Figure 7-2: Engagement Limit Indications Upon ESP Activation
Engagement Limit
Indication at 45°
Lower Disengagement Limit
Indication depicted at 30° after ESP
activation
AFMS – GFC 500 Autopilot in Piper PA-28 Series 190-02291-07 Rev. 1
Page 7–4
Disconnect Methods
The following conditions will cause the autopilot to automatically disconnect:
Electrical power failure, including pulling the AUTOPILOT circuit breaker.
Internal autopilot system failure (including internal AHRS failure).
The following pilot actions will cause the autopilot to disconnect:
Pressing the red AP DISC / TRIM INT button on the pilot’s control wheel.
Actuating the manual electric trim switch (if installed).
Pushing the AP Key on the GMC 507 mode controller when the autopilot is engaged.
Pulling the AUTOPILOT circuit breaker.
The red AP DISC / TRIM INT button on the pilot’s control wheel will interrupt power to the manual electric trim for
as long as the switch is depressed.
AUTOPILOT CONTROL UNIT AND DISPLAY
Figure 7-3: GMC 507 Control Unit (Reference Only)
Figure 7-4: G5 Display (Reference Only)
190-02291-07 Rev. 1 AFMS – GFC 500 Autopilot in Piper PA-28 Series
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The following tables list the available AFCS vertical and lateral modes with their corresponding controls and
annunciations. The UP/DN wheel can be used to change the vertical mode reference while operating in Pitch
Hold, Vertical Speed, Altitude Hold, or IAS mode. Increments of change and maximum ranges of values for
each of these references using the UP/DN wheel are also listed in the table.
AFCS VERTICAL MODES
Vertical Mode Control Annunciation Reference Range
Reference Change
Increment
Pitch Hold (default) PIT
20° Nose Up
15° Nose Down
0.5°
Selected Altitude
Capture
* ALTS
Altitude Hold ALT Key ALT nnnnn 10 FT
Vertical Speed VS Key VS nnnn
-2000 to +2000
FPM
100 FPM
IAS Hold IAS Key IAS nnn
65 to 140 KIAS
75 to 160 MPH
1 KT
1 MPH
Vertical Path
Tracking (VNAV)
VNV Key N/A
Glidepath
APR Key
GP
Glideslope GS
Takeoff or Go
Around
GA Button TO or GA 7°
Level (LVL) LVL Key LVL
Zero Vertical
Speed
ESP High Pitch
Engagement
ESP High Pitch Attitude engages at 20° nose up
ESP Low Pitch
Engagement
ESP Low Pitch Attitude engages at 15° nose
down
ESP High
Airspeed
Engagement
ESP High Airspeed engages at above V
NE
+ 1
KIAS (1 MPH)
ESP Low
Airspeed
Engagement
When above 200 FT AGL, ESP Low Airspeed
engages at below Vs + 5 KIAS (5 MPH). (This
mode only available if height above terrain is
available from a compatible Garmin GPS).
* ALTS arms automatically when PIT, VS, IAS, or GA is active.
AFMS – GFC 500 Autopilot in Piper PA-28 Series 190-02291-07 Rev. 1
Page 7–6
AFCS LATERAL MODES
Lateral Mode Control Annunciation
Maximum Roll
Command Limit
Roll Mode
(default) ROL 30°
Heading Select
HDG Key HDG 30°
Track Select TRK Key TRK 30°
Navigation, GPS Arm/Capture/Track
NAV Key
GPS 30°
Navigation, VOR Enroute and Approach
Arm/Capture/Track
VOR 30°
Navigation, LOC Arm/Capture/Track (No
Glideslope)
LOC 30°
Backcourse Arm/Capture/Track BC 30°
Approach, GPS Arm/Capture/Track
(Glidepath Mode Automatically Armed, if
available)
APR Key
GPS 30°
Approach, ILS Arm/Capture/Track
(Glideslope Mode Automatically Armed)
LOC 30°
Takeoff or Go Around
GA Button TO or GA Wings Level
LVL (Level)
LVL Key LVL Wings Level
ESP Roll Attitude Engagement
ESP Roll
Attitude
engages at 45°
The autopilot may be engaged within the following ranges:
Pitch 50° nose up to 50° nose down
Roll ±75°
If the above pitch or roll limits are exceeded while the autopilot is engaged, the autopilot will disconnect. Engaging
the autopilot outside of its command limits, but within its engagement limits, will cause the autopilot to return the
aircraft within command limits. The autopilot is capable of commanding the aircraft in the following ranges:
Pitch 20° nose up to 15° nose down
Roll ±30°
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Page 7–7
PREFLIGHT TEST
During the preflight test the G5 will display PFT in the autopilot status box. The autopilot disconnect tone sounds
at the completion of the preflight test and the PFT annunciation is removed. If GFC 500 fails the PFT, a yellow AP
with a red X is displayed in the autopilot status box on the G5.
MESSAGES AND ANNUNCIATIONS
Autopilot Messages
AFCS Controller Key
Stuck
The system has sensed a key input on the GMC 507 for 30 seconds or
longer.
AFCS Controller Audio
Database Missing
The audio database is missing from the GMC 507. The aural voice alerts
will not be heard.
Servo Clutch Fault One or more autopilot servos has a stuck clutch. The servo needs service.
Servo Trim Input Fault The inputs to the trim system are invalid. The trim system needs service.
Autopilot Annunciations
Autopilot has failed. Autopilot and trim are inoperative and flight director is
not available.
Autopilot normal disconnect.
Autopilot abnormal disconnect.
Autopilot has failed. The autopilot is inoperative. FD modes may still be
available.
Autopilot Overspeed Protection mode is active. Autopilot will raise the nose
to limit the aircraft’s speed.
Autopilot Underspeed Protection mode is active. Autopilot will lower the
nose to prevent the aircraft’s speed from decreasing.
Autopilot preflight test is in progress.
Pitch Trim Fail – Manual Electric Pitch Trim is inoperative.
Elevator Trim Down – Autopilot is holding elevator nose down force. The
pitch trim needs to be adjusted nose down.
Elevator Trim Up – Autopilot is holding elevator nose up force. The pitch
trim needs to be adjusted nose up.
AFCS
AP
AP
AP
MAXSPD
MINSPD
PFT
PTRIM
TRIM DOWN
TRIM UP
AFMS – GFC 500 Autopilot in Piper PA-28 Series 190-02291-07 Rev. 1
Page 7–8
LIGHTING
When the aircraft’s dimming bus is selected off, or full dim, GMC 507 mode control panel lighting is controlled by
integrated photocells which sense the ambient cockpit lighting.
