Garmin GFC 600H Manual

GFC 600H
Pilot’s Guide for Bell 505
™

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June, 2021 190-02775-00 Rev.A Printed in the U.S.A.

Garmin GFC 600H Pilot’s Guide for Bell 505
190-02775-00 Rev. A
Warnings, Cautions & Notes
WARNING: Perform a thorough preflight control check to verify that there is
no excessive friction, binding, or other anomalies that prevent smooth control
movement throughout the intended range of motion in pitch, roll, and yaw
axis. Any discrepancies must be resolved prior to operation. In addition, the
friction set from the manual cyclic friction lock must be fully removed prior
to flight.
WARNING: For safety reasons, system operational procedures must be learned
on the ground.
WARNING: The Garmin system, as installed in this rotorcraft, has a very
high degree of functional integrity. However, the pilot must recognize that
providing monitoring and/or self-test capability for all conceivable system
failures is not practical.
WARNING: To reduce the risk of unsafe operation, carefully review and under-
stand all aspects of the system, Pilot’s Guide documentation, the Rotorcraft
Flight Manual, and the Flight Manual Supplement. Thoroughly practice basic
operation prior to actual use.
CAUTION: The system does not contain any user-serviceable parts. Repairs
should only be made by an authorized Garmin service center. Unauthorized
repairs or modifications could void both the warranty and the pilot’s authority
to operate this device under FAA/FCC regulations.
NOTE: All visual depictions contained within this document, including screen
images of the panel and displays, are subject to change and may not reflect
the most current system and aviation databases. Depictions of equipment
may differ slightly from the actual equipment.
NOTE: This device complies with part 15 of the FCC Rules. Operation is
subject to the following two conditions: (1) this device may not cause harm-
ful interference, and (2) this device must accept any interference received,
including interference that may cause undesired operation.

Garmin GFC 600H Pilot’s Guide for Bell 505
190-02775-00 Rev. A
SOFTWARE LICENSE AGREEMENT
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Garmin GFC 600H Pilot’s Guide for Bell 505
190-02775-00 Rev. A
Part Number Change Summary
190-02775-00 Initial release
Rev Date Description
A June, 2021 Production Release

Garmin GFC 600H Pilot’s Guide for Bell 505
190-02775-00 Rev. A i
Table of Contents
Section 1 System Overview .................................................................................................. 1
1.1 Basic Functions .................................................................................................................. 1
1.2 HFCS Equipment ................................................................................................................ 2
GMC 605H Mode Controller ................................................................................................ 3
GFS 83 Servo ....................................................................................................................... 3
Attitude and Air Data Sensors............................................................................................... 4
1.3 HFCS Controls..................................................................................................................... 6
GMC 605H (3-Axis).............................................................................................................. 6
External Controls.................................................................................................................. 7
1.4 System Indications............................................................................................................ 9
GMC 605H .......................................................................................................................... 9
Garmin PFD HFCS Indications............................................................................................. 12
Section 2 Helicopter Flight Control System .............................................................. 13
2.1 HFCS Operation................................................................................................................ 13
HFCS Pre-Flight.................................................................................................................. 13
Engaging the Helicopter Flight Control System.................................................................... 14
Disengaging the Helicopter Flight Control System ............................................................... 14
Upper Modes ..................................................................................................................... 15
HFCS Operation Limitations................................................................................................ 16
2.2 Basic Helicopter Flight Control System Features..................................................... 16
Attitude Hold Mode (ATT)................................................................................................... 16
2.3 Vertical Coupled Modes.................................................................................................. 19
Vertical Coupled Mode Controls and Annunciations ............................................................ 19
Altitude Hold Mode (ALT) ................................................................................................... 20
Selected Altitude Capture Mode (ALTS) ............................................................................... 21
Vertical Speed Mode (VS) ................................................................................................... 22
Indicated Airspeed Mode (IAS)............................................................................................ 23
Glidepath Mode (GP) ......................................................................................................... 23
Glideslope Mode (GS)......................................................................................................... 25
2.4 Lateral Coupled Modes................................................................................................... 26
Lateral Coupled Mode Controls and Annunciations ............................................................. 26
Heading Select Mode (HDG)............................................................................................... 27
Navigation Modes (GPS, VOR, LOC) .................................................................................... 28
Approach Modes (GPS, VAPP, LOC)..................................................................................... 30
Flying An Arc With A GPS Navigator.................................................................................... 33
2.5 Helicopter Electronic Stability & Protection (H-ESP™) ........................................... 33
Limit Cueing ...................................................................................................................... 34
Overspeed Protection ......................................................................................................... 36
Low speed Protection......................................................................................................... 37

Garmin GFC 600H Pilot’s Guide for Bell 505
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ii
Table of Contents
Section 3 Annunciations & Alerts .................................................................................... 39
3.1 Visual Annunciations and Alerts .................................................................................. 39
3-Color LED ....................................................................................................................... 39
GMC 605H CAS Messages ................................................................................................. 40
GMC 605H Annunciations.................................................................................................. 42
3.2 Aural Alerts....................................................................................................................... 43
Voice Alerts........................................................................................................................ 43
Flight Control System Disconnect Alert................................................................................ 44
Section 4 Abnormal Operation ......................................................................................... 45
4.1 Suspected Flight Control System Malfunction......................................................... 45
Section 5 Terms & Conventions........................................................................................ 47
5.1 Equipment Terminology................................................................................................. 47
5.2 System Operation Terminology ................................................................................... 47
5.3 Helicopter and System Controls .................................................................................. 49
5.4 Mode Annunciations....................................................................................................... 50
Section 6 Index....................................................................................................................Index-1
Index...................................................................................................................................Index-2

Garmin GFC 600H Pilot’s Guide for Bell 505
190-02775-00 Rev. A 1
System Overview
SECTION 1 SYSTEM OVERVIEW
The Garmin GFC 600H is an attitude-based, Helicopter Flight Control System (HFCS)
that supports an extensive set of operating modes and safety features.
CAUTION: This manual covers all functions and modes that the GFC 600H
can support; however, it is the responsibility of the user to become familiar
with the capabilities and limitations (per the Bell 505 Rotorcraft Flight
Manual Supplement).
1.1 BASIC FUNCTIONS
The GFC 600H HFCS provides the following main operating functions:
• Attitude Hold (ATT) — Attitude Hold Mode (ATT) is the lowest functional
mode of the GFC 600H system. When in ATT, the system moves the primary flight
controls to maintain a pitch and roll attitude set by the pilot. ATT can be used
throughout the entire flight envelope.
• Groundspeed Hold (GSPD) — Groundspeed Hold Mode (GSPD) is automatically
engaged when either airspeed decreases below 30 kts or groundspeed decreases
below 15 kts. While in Groundspeed Hold Mode, the FCS maintains a set
groundspeed. Groundspeed Hold Mode automatically deactivates when airspeed
exceeds 35 kts and groundspeed exceeds 20 kts.
• Level Mode (LVL) — Level Mode (LVL) controls the rotorcraft to a pitch attitude
intended to maintain steady flight under most conditions and a lateral reference
of zero bank angle. Level Mode may be engaged from any airspeed or attitude
within the GFC 600H engagement limits.
• Yaw Control (Optional) — The GFC 600H system may be optionally equipped
with a yaw axis servo. The Bell 505 uses a high torque variant of the GFS 83 servo
in order to operate the un-boosted yaw controls in this aircraft. The functionality
provided by the yaw servo is dependent upon airspeed. At low airspeeds, yaw
assists this pilot in maintaining aircraft heading. At higher airspeeds, the yaw axis
maintains coordinated flight. A yaw trim switch is mounted on the collective to
allow for lateral acceleration adjustments in cruise flight.

Garmin GFC 600H Pilot’s Guide for Bell 505
190-02775-00 Rev. A
2
System Overview
• Upper Mode Engagement — The GFC 600H system provides a means to
couple the FCS to pitch and or roll Upper Modes. Upper Modes may be selected
using the GMC 605H mode keys when above 45 KIAS. Coupled modes will
automatically disengage if the airspeed drops below 35 KIAS. Upper Mode keys
include HDG, NAV, APR, IAS, VS, and ALT.
1.2 HFCS EQUIPMENT
The basic GFC 600H system is comprised of the following equipment:
GFC 600H System

Garmin GFC 600H Pilot’s Guide for Bell 505
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System Overview
GMC 605H MODE CONTROLLER
The panel-mounted GMC 605H serves as the primary user interface for the GFC 600H.
The GMC provides mode selection buttons and a wheel for convenient adjustment of
the Upper Mode vertical references. A backlit monochrome NVIS (night vision) friendly
LCD displays active and armed modes, reference values, alerts, and messages.
The GMC 605H has extensive I/O capabilities that support interfaces to equipment
including Primary Flight Display, Air Data Computers, FMS, VHF Nav radios, and Audio
Panel. The GMC includes internal attitude and rate sensors used to monitor the
external AHRS performance. The GMC utilizes sensor data from an external air data
computer, magnetometer and GPS receiver to provide required inputs to the internal
attitude and rate sensors.
GMC 605H
GFS 83 SERVO
The GFS 83 is a ‘smart’ servo which performs many FCS processing functions. The
GFS 83 servo actuates the flight controls of the rotorcraft and is installed in parallel
with the primary flight controls, resulting in cyclic and anti-torque pedal movement
directly proportional to servo movement. The servos are installed in pitch, roll and
optionally yaw.
The GFS 83 provides fly through capabilities, meaning that the pilot can override
the system at any time flying through any control forces which may be present. Upon
releasing the controls the system will return to its commanded references. There are
multiple variants of the GFS 83 which offer different functions.

Garmin GFC 600H Pilot’s Guide for Bell 505
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4
System Overview
The GFS 83 contains a brushless motor and a geared drive train to provide smooth
and reliable operation. The pitch and roll servos provide a fail passive damping feature
which reduces aircraft attitude deviation in the event of servo disconnect while the
pilot’s hands are not on the controls. The yaw servo is a high-torque version of the
GFS 83 and does not provide a fail passive damping feature. The GFS 83 is installed in
the pitch, roll, and yaw axes. In the event of a mechanical jam in the servo, the pilot
must apply force to the affected rotorcraft flight control to break the shear device at
the output shaft of the servo, removing the servo from the control system and allowing
free movement of the flight control.
GFS 83 (Direct Drive)
ATTITUDE AND AIR DATA SENSORS
The GFC 600H system uses a minimum of two attitude sources and one air data
source. The GMC 605H provides one attitude solution which is used to monitor the
primary attitude solution provided by a GSU 75H ADAHRS sensor.
The GSU 75H is a remotely mounted ADAHRS which combines attitude and
rate sensors with an air data computer. The AHRS sensor includes tilt sensors,
accelerometers, and rate sensors which provides attitude, heading, and rate data to
both the G1000 and the GFC 600H system. The GSU 75H requires interfaces to the
GMU 44 magnetometer, and a GIA 63/64 GPS/SBAS receiver.
The GMU 44 magnetometer senses magnetic fields and sends the data to the AHRS
to determine the magnetic heading. The GMU 44 magnetometer is interfaced to both
the primary attitude sensor and to the GMC 605H.

Garmin GFC 600H Pilot’s Guide for Bell 505
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System Overview
The Air Data Computer functionality of the GSU 75H connects to the existing pitot-
static system and a GTP 59 OAT probe. The GSU 75H provides pressure altitude,
airspeed, vertical speed and OAT data to the G1000 and the GFC 600H system.
The GTP is a remotely mounted temperature probe that interfaces to the Air Data
Computer for determination of OAT and true airspeed.
GSU 75H
GPS
A Garmin GPS is required as an aiding source for the GMC 605H and GSU 75H
ADAHRS and for GPS based modes including Groundspeed Hold and GPS navigation.
COLLECTIVE POSITION SENSOR
The GFC 600H collective position sensor provides collective position to the GFC
600H to improve FCS performance.

Garmin GFC 600H Pilot’s Guide for Bell 505
190-02775-00 Rev. A
6
System Overview
1.3 HFCS CONTROLS
GMC 605H (3-AXIS)
GMC 605H (3-AXIS) HFCS Mode Controller
910
6
32
578
1
Roll Mode
Pitch Mode
Pitch Reference
Servos
Engaged CAS
Message
Lateral Mode
Keys Pitch Mode
Keys
4
1
FCS Key Engages/disengages the Flight Control System
2
LCD Display Displays HFCS modes, references, and annunciations.
3
LVL Key Engages the Flight Control System in Level Mode (or selects Level
Mode if Flight Control System is already engaged).
4
HDG Key Selects/deselects Heading Select Mode
5
NAV Key Selects/deselects Navigation Mode. Cancels GS Mode if LOC
Mode is either active or armed. Cancels GP Mode if GPS Mode is
either active or armed.
6
APR Key Selects/deselects Approach Mode
7
IAS Key Selects/deselects Indicated Airspeed Mode
8
VS Key Selects/deselects Vertical Speed Mode
9
ALT Key Selects/deselects Altitude Hold Mode
10
NOSE UP/DN
Wheel
Adjusts the reference in Vertical Speed, Indicated Airspeed, and
Altitude Hold modes

Garmin GFC 600H Pilot’s Guide for Bell 505
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System Overview
EXTERNAL CONTROLS
These controls provide FCS control functions but are not found on the GMC 605H.
Cyclic Switches Collective Switches
Force Trim
Release

Garmin GFC 600H Pilot’s Guide for Bell 505
190-02775-00 Rev. A
8
System Overview
Control Common
Name
Typical
Location/
Color
Purpose
FTR/FCS
Engage
Force Trim
Release Cyclic (Black)
Servos Disengaged: Momentary press engages
the HFCS pitch and roll axes.
Any Engaged Mode: Press and hold will reduce
the control forces for the duration of time that
the switch is depressed. After 1 second the
system will annunciate ‘FTR’ as indication that
an extended press is active.
ATT Mode: Press and hold reduces control
forces and continuously synchronizes the pitch
and roll attitude reference. Upon release
synchronizes the pitch and roll attitude
reference to current values.
CPLD Upper Modes: Upon release synchronizes
the pitch reference (VS, ALT, IAS) to the current
value as applicable.
FCS DISC
Flight
Control
System
Disconnect
Cyclic (Red)
Momentary Press: Disengages all coupled
Upper Modes. Servos remain engaged in ATT
Mode.
Double momentary press OR press and hold for
1 second: Disengages the pitch, roll, and yaw
servos.
Press and hold for 6 seconds: Toggles limit cue
ON/OFF.
TRIM Cyclic
Beep Trim Cyclic (Black)
Single Press: Increments the HFCS references.
Press and Hold: Slews the HFCS references.
ATT Mode: The trim switch changes the
reference pitch (+/-) and roll (+/-) attitude.
CPLD Upper Modes: The trim switch changes
the reference altitude, vertical speed, or
indicated airspeed, as applicable.
LVL Level Mode Cyclic (Blue) Engages the pitch, roll, and optional yaw axis in
LVL Mode.

Garmin GFC 600H Pilot’s Guide for Bell 505
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System Overview
Control Common
Name
Typical
Location/
Color
Purpose
YAW Yaw On/Off Collective
(Black) Engages/disengages the yaw control.
YAW TRIM Yaw Beep
Trim
Collective
(Black)
In cruise, this switch allows the aircraft to be
trimmed out of ball center.
External Controls Summary
1.4 SYSTEM INDICATIONS
GMC 605H
The GMC 605H provides indications to the pilot via a monochrome LCD combined
with one color LED located adjacent to the FCS key.
The left side of the LCD displays lateral Upper Modes, the center portion of the
display provides vertical modes and references, and the right side of the display serves
as a message area for status and alerts. Active modes and references are depicted in
large letters along the upper portion of the display, with armed modes in a smaller
font below the active modes. The message area can display up to four messages
simultaneously.
Text can be flashed alternating between normal display and inverse video for
conditions which require the pilot’s attention.

Garmin GFC 600H Pilot’s Guide for Bell 505
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10
System Overview
GMC 605H LCD Display
Active Lateral
Mode Active Vertical
Mode Mode
Reference
Armed Vertical
Modes
Armed Lateral
Mode
Servo
Status
Status Messages and
Alerts
The LED adjacent to the FCS key is illuminated in conjunction with other information
on the LCD to provide status and alert information.
The FCS LED illuminates in green to indicate engagement. Manual FCS disconnect
or abnormal dropping of an Upper Mode is indicated with a flashing yellow FCS
annunciation, and red is used to indicate an abnormal disconnect or failure condition.
FCS LED
GMC 605H LED
Refer to section 3.1 for more information about specific GMC 605H messages and
LED annunciations.
SERVO STATUS
The servo status field (R=Roll, Y=Yaw, P=Pitch) indicates when the servos are
engaged. This field also provides an indication when the servos are out of detent.

Garmin GFC 600H Pilot’s Guide for Bell 505
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System Overview
The default when turning the system on in ATT mode is pitch, roll, and (optionally)
yaw servo engagement. The yaw servo can be disengaged or re-engaged via the
collective mounted Yaw ON/OFF switch.
The Out of Detent (inverse video) annunciation indicates to the crew that an external
force (crew input) in excess of the breakout force is being applied to the servo and
the FCS is no longer controlling the aircraft in that axis. The P, R,or Yinverse video
annunciation indicates the servo is out of detent. If a servo is held out of detent for
an extended period of time a system message will also indicate the out of detent
condition.
CAUTION: When a servo indicates that it is Out of Detent the FCS is no
longer maintaining the reference in that axis and the pilot must be in
control.
GMC 605H Servo Status
Roll Servo (Out of Detent)
Yaw Servo (Engaged)
Pitch Servo (Engaged)

Garmin GFC 600H Pilot’s Guide for Bell 505
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12
System Overview
GARMIN PFD HFCS INDICATIONS
The following CAS or alert messages may be present on the PFD:
NOTE: A red FCS annunciation on the PFD indicates a system failure.
Condition Annunciation
FCS Failed - The FCS is inoperative FCS - FAIL
System is unable to provide yaw axis control FCS - YAW FAIL
PFT is in progress FCS - PFT
PFT has failed FCS - PFT FAIL
Limit Cue is off FCS - LMTQ OFF
Overspeed Protection active or V
ne
Limit Cue active FCS - MAXSPD
Low speed protection is active FCS - LOWSPD
A failed data path may indicate that the HFCS system has
been turned off or there is a failed communication path
between the GFC 600H and the GIA 63 or GIA 64.
Failed Data Path
PFD Visual Alerts and Messages
Refer to the applicable Garmin G1000H or G1000H NXi Pilot’s Guide for detailed
information.