Textron Bendix/King KFC 500 Manual

KFC 500
Pilot’s Guide
Bendix/King®
Dual Automatic Flight Control System
for the Model 430
006-18081-0000 June 1999

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Revision History
R-1
June 15, 1999 006-18081-0000
Revision History and Instructions
Manual KFC 500 Pilot’s Guide
Revision 1, June 1999
Part Number 006-18081-0000
This revision consists of the folowing:
Add text further describing the operation of the push-buttons, the push-but-
ton annunciators, and the EADI annunciators to the following pages - 20,
23, 25, 26, 27, 30, 31, 37, 46, 47, 50, 51, 53, 56, 57, 59, 60, 61, 63, 64, 65,
67, 68, 69, 71, 72, 73
Administrative changes to the following pages - Front Cover, Inside of Front
Cover, 1, 2, 12, 22, 23, 24, 25, 28, 29, 31, 32, 33, 34, 35, 37, 38, 46, 47,
48, Back Cover
Remove Yaw Trim - 21, 55
Revise Attitude Hold Roll Command Limit - 76

Revision History
R-2
June 15, 1999 006-08769-0000

1
Table of Contents
006-18081-0000 June 15, 1999
Introduction ................................................................................3
Normal Operation
SCAS/Autopilot....................................................................5
SCAS/Autopilot Block Diagram............................................7
Basic Dual SCAS/AP Operation ..........................................8
SCAS/AP Remote Switches ................................................8
Force Trim 1/OFF ................................................................8
Force Trim 2/OFF ................................................................8
AFCS GROUND TEST ........................................................9
SCAS & AP PWR 1/OFF .....................................................9
SCAS & AP PWR 2/OFF .....................................................9
TEST/BRT/DIM (AFCS Lamp Test)...................................10
SCAS/AP Annunciators .....................................................10
Modes of Operation ...........................................................11
SCAS Mode.......................................................................11
AP Mode............................................................................12
Lateral Command Control..................................................13
Pitch Command Control.....................................................14
SCAS/Autopilot Disconnect ...............................................15
Force Trim Release (FTR).................................................15
Yaw Force Trim Release ...................................................16
Flight Director.........................................................................17
SCAS/Autopilot/Flight Director Block Diagram ..................19
SCAS/AP Operation (Flight Director Installed) ..................20
Yaw Force Trim Release.............................................20
Yaw Trim .....................................................................21
Flight Director Operation....................................................21
Modes of Operation.....................................................21
Pitch Attitude Hold & Roll Attitude Hold (FD)...............23
Lateral Command Control ...........................................23
Vertical Command Control ..........................................24
Force Trim Release (FTR)...........................................26
Flight Director Off ........................................................26
Go Around...................................................................27
Autopilot/Flight Director Mode Annunciation ...............28
KMS 540 Flight Director Mode Selection...........................29
Heading Select (HDG).................................................29
Bank Angle Limit (BL)..................................................29
Navigation Mode (NAV)...............................................30
Approach Mode (APR) ................................................30

3
Introduction
006-18081-0000 March 27, 1998
The dual KFC 500 Automatic Flight
Control System is available in two
configurations for the Bell 430.
These configuration are a basic dual
three axis SCAS/Autopilot system
and a dual three axis SCAS/Autopilot
with single Flight Director system.
The dual system configuration is
composed of a pilot selectable pri-
mary (# 1) and secondary (# 2) con-
trol system. The primary and sec-
ondary systems each have a
separate flight control computer with
dedicated roll and pitch axes servos.
The primary and secondary systems
are also configured with required
dedicated sensors such that there is
a high degree of probability that dur-
ing any flight the basic Autopilot
Attitude/Heading Hold functions in
the pitch and roll axes will be avail-
able to the flight crew. The other
basic control elements are switched
between the selected flight control
systems such that under normal con-
ditions the secondary system will
have the same basic Autopilot/SCAS
functionality as the primary system
except for Force Trim fly-through
capability. Flight Director functions
(available only with SCAS/Autopilot
with Flight Director system) are only
provided when the primary system is
selected. The basic SCAS/Autopilot
system provides the same capability
as the system with Flight Director in
the basic SCAS and AP Autopilot
modes. In case of failure of the pri-
mary system the secondary system
may be selected by the crew to
maintain required work-load relief.
This secondary system operating as
a “hot standby spare” must be pre-
flight tested and passed prior to
departure to insure that it will be
available if needed during flight and
that full control authority is available.
The KFC 500 primary
SCAS/Autopilot with Flight Director
system is integrated with the KAD
480 Central Air Data System and the
electronic flight instrument system to
enhance user-friendliness as well as
system annunciation. This system
combines complete stability augmen-
tation, autopilot, and optional flight
director computation functions in a
single computer. Its digital flight com-
puter and integrated architecture
enable the KFC 500 to determine
helicopter control requirements
sooner, and to execute them with
greater smoothness and accuracy
than previous generation systems.
Digital, solid-state design throughout
the Flight Control System provides
maximum reliability while economiz-
ing on system weight and required
installation space. The KFC 500 is
designed to optimize passenger and
flight crew comfort, while still provid-
ing accurate control response in any
flight situation. Whenever possible,
autopilot induced aircraft motions
border on the lower limits of human
perceptibility, ensuring exceptionally
smooth flight. The Flight Control
System’s maximum command val-
ues were tailored for the Bell 430
during the aircraft certification pro-
cess. Internal safety monitors and
automatic self-test functions keep
constant track of the KFC 500’s sta-
tus, and provide signals for auto-
matic shutdown of impaired control
axes or flight director functions if
2
Table of Contents
June 15, 1999 006-18081-0000
Normal Operation (Continued)
Autolevel Mode............................................................32
Altitude Select (ALT SEL)............................................32
Altitude Hold (ALT)......................................................33
Indicated Airspeed Hold (IAS).....................................34
Overspeed Protection..................................................34
Vertical Speed Hold (VS).............................................34
KAV 485 Vertical Speed Select...................................35
Flight Control System Components ...................................36
KSA 572 Trim Actuator................................................36
Force Trim and AP Trim..............................................36
KSM 575 Linear Actuator Assemblies.........................37
KCP 520 Flight Computer............................................37
AFCS Sensors...................................................................37
KVG 350 Attitude Gyro................................................37
KCS 305 Slaved Compass System.............................37
KRG 333 Rate/Acceleration Sensor............................38
Control Position Transducer........................................38
KAD 480 Air Data System...........................................38
KDC 481T Air Data Computer...............................38
KAV 485 Altitude/Vertical Speed Indicator............39
Emergency Procedures/Limitations............................................43
Preflight Procedures.....................................................................45
Operational Examples ..................................................................49
Performance Specifications.........................................................75

5
KFC 500
Dual SCAS/
Autopilot
Normal Operation
006-18081-0000 March 27, 1998
4
Introduction
March 27, 1998 006-18081-0000
Important:
This Pilot’s Guide provides a general description of the
various operational characteristics of the dual KFC 500 Flight
Control System. However, operation of the system should not be
attempted without first reviewing the applicable Transport Canada
and/or Federal Aviation Administration Approved Rotorcraft Flight
Manual for complete system familiarization and operating
limitations.
available. When the KFC 500 de-
couples a SCAS/autopilot axis it both
engages the affected servo brake
and shuts off motor drive power, pro-
viding dual layers of protection
against servo over-control. In addi-
tion to reliability and light weight, the
KFC 500 is designed to be easily
maintained in the field. Self-con-
tained diagnostic tests assist trouble-
shooting done by maintenance per-
sonnel at Honeywell factory
approved service centers. The Built-
In-Test functions enable a technician
to trace faults. Qualified Honeywell
service centers around the world are
ready to provide assistance when-
ever necessary.

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6006-18081-0000
March 27, 1998 7
Normal Operation
006-18081-0000 March 27, 1998
KCP 520
ı
KCP 520
ı
ı
AP SCAS
Primary KRG 333
Rate/Acceleration Sensor
Primary
KCP 520
Flight
Computer
KMS 541
Mode Selector
KCS 305 Compass
Trim Actuator
Primary Pitch
Linear Actuator
Control Position
Synchro
Cyclic
Switches
PITCH
ROLL
YAW
Collective
Switches
Primary KVG 350
Vertical Gyro
IIDS
Control Position
Synchro
Control Position
Synchro
Collective Control
Position Synchro
Trim Actuator
Primary Roll
Linear Actuator
Trim Actuator
Linear Actuator
SCAS/AP Remote
Switches/Annunciators
MAN
CW
AUTO
CCW
-
+
KSG 105
1
DIRECTION
OFFLIGHT
RADIO
ICS
FOOT
SW
RADIO
ICS
FOOT
SW
FORCE
TRIM 1
OFF
AP ON
SCAS ON
FORCE
TRIM 2
OFF
AP
1 2
SCAS &
AP PWR 2
OFF
SCAS &
AP PWR 1
OFF
Secondary
KCP 520
Flight
Computer
Secondary KRG 333
Rate/Acceleration Sensor
DIRECTION
OFFLIGHT
Secondary KVG 350
Vertical Gyro
Secondary Pitch
Linear Actuator
Secondary Roll
Linear Actuator
AFCS
GROUND
TEST
Basic Dual KFC 500 SCAS/Autopilot System Block Diagram

Normal Operation Normal Operation
89
March 27, 1998 006-18081-0000
006-18081-0000 March 27, 1998
ation is not illuminated.
AFCS GROUND TEST
This momentary switch, located on
the overhead panel below the
Emergency Bus 2 Breakers, is used
to initiate the SCAS/AP System pre-
flight test, on both systems if desired,
after the initial test that occurs at
system power up. At power up, or
when AFCS Ground Test switch is
pressed, the non-selected system
will continue to annunciate the asso-
ciated system AP and SCAS FAIL
Cautions until such time the system
is selected and allowed to complete
interactive power up preflight tests.
Preflight test must be run prior to
attempting system engagement on
the selected system. SCAS/AP
engagement will be disallowed in
any axis that has not successfully
passed preflight test. The system will
allow engagement and use of any
available axis (roll, pitch, and/or yaw)
that has passed. While performing
preflight test is only recommended
on the ground it may be performed in
the air as well, see Transport
Canada and/or Federal Aviation
Administration Approved Rotorcraft
Flight Manual for any restrictions
placed on this operation in the air.
may be selected to continue the flight
with basic AP and SCAS modes
available. Any modes engaged
when AP Select switch is toggled will
be canceled and desired modes on
newly selected system must be re-
engaged.
Force Trim 1/OFF
Depressing the FORCE TRIM 1/OFF
switch, located on the center
pedestal just above the Mode Select
Panel, will turn power on or off to the
Force Trim system when the primary
flight control system is selected.
Power is available and the system is
on when the OFF annunciation is
not illuminated.
Force Trim 2/OFF
Depressing the FORCE TRIM 2/OFF
switch, located on the center
pedestal just above the Mode Select
Panel, will turn power on or off to the
Force Trim system when the sec-
ondary flight control system is
selected. Power is available and the
system is on when the OFF annunci-
Basic Dual SCAS/AP
Operation
This section provides the Normal
Operating Procedures for the basic
dual SCAS/AP version of the KFC
500 System.
SCAS/AP Remote Switches
There are seven remote switches for
the system. They are located on the
center pedestal and overhead pan-
els.
AP 1/2 Select Switch
Depressing the AP 1/2 switch
located on the center pedestal just
above the Mode Select Panel will
alternately select the primary (1) or
secondary (2) AFCS systems. When
1is illuminated the primary system is
selected and when 2is illuminated
the secondary system is selected.
Normally the primary system will be
used, unless a failure has occurred
affecting AP mode availability, in
which case the secondary system
RADIO
ICS
FOOT
SW
RADIO
ICS
FOOT
SW
FORCE
TRIM 1
OFF
AP ON
SCAS ON
FORCE
TRIM 2
OFF
AP
1 2
AP
1 2
AP
1 2
AP
12
AFCS
GROUND
TEST
FORCE
TRIM 1
OFF
FORCE
TRIM 2
OFF
FORCE
TRIM 2
FORCE
TRIM 1
SCAS & AP PWR 1 /OFF
Depressing the SCAS & AP PWR
1/OFF switch located on the center
pedestal, just to the right of the
Mode Select Panel, will turn power
on or off to the Primary (#1)
SCAS/AP system. Power is avail-
able to the system when the OFF
annunciation is not illuminated.
SCAS & AP PWR 2/OFF
Depressing the SCAS & AP PWR
2/OFF switch located on the center
pedestal, just to the right of the
Mode Select Panel, will turn power
on or off to the Secondary (#2)
SCAS/AP system. Power is avail-
able to the system when the OFF
annunciation is not illuminated.
SCAS &
AP PWR 1
OFF
SCAS &
AP PWR 1
SCAS &
AP PWR 2
OFF
SCAS &
AP PWR 2

Normal Operation Normal Operation
10 11
March 27, 1998 006-18081-0000
006-18081-0000 March 27, 1998
has been detected or if SCAS/AP
PWR is OFF. Single axis failures will
not cause the SCAS (yellow) or AP
(yellow) annunciation’s to light on the
selected system. You will get an axis
failure only (i.e. AFCS PIT). A roll or
pitch axis failure indicates that con-
trol of that axis has been lost. A yaw
axis failure indication means that
yaw axis or trim follow up in yaw axis
is lost. If it is only a yaw trim axis fail-
ure the annunciator will extinguish if
SCAS engaged. An Autotrim failure
indication means that roll or pitch trim
has failed and more attention will
need to be given to see that the sys-
tem is kept within the control author-
ity of the main servo by using the
FTR switch to keep the system work-
ing within its control range. The non-
selected system will annunciate AP
and SCAS Fail annunciation for sin-
gle axis failures in roll, pitch and/or
Rate Gyro failure. The non-selected
system will annunciate AP Fail for
pitch and roll trim axis failure and / or
when vertical acceleration is invalid
or Vertical Gyro is invalid after nor-
mal power up delay. If this side is
selected then the annunciation will
display the single or multiple axis fail-
ures applicable and clear the AP and
/ or SCAS Fail annunciation if any
axis is available for use.
Modes of Operation
The KMS 541 Mode Select Panel
provides control and annunciation of
the KFC 500’s SCAS and AP (atti-
tude retention) modes of the selected
system. To activate the SCAS or AP
modes using the Mode Select Panel,
momentarily press the desired push-
button. The corresponding mode
lamp will illuminate above the switch.
Alternatively, to deactivate the SCAS
or AP mode when activated, momen-
tarily press the respective push-but-
ton (The AP mode reverts to SCAS
when deselected). There are remote
repeater AP ON, SCAS ON annunci-
ators located above the mode selec-
tor panel that is switched to the
selected system. These annunciators
will mimic the ones located above
the mode switches on the Mode
Select Panel. The brightness of the
annunciator lamps on the mode con-
troller is adjusted automatically by a
photocell located on the face of the
unit. The button nomenclature back
lighting is controlled by the pedestal
dimmer control on the overhead
panel.
SCAS Mode
Momentarily pressing the SCAS but-
ton on the Mode Select Panel will
activate the stability augmentation
mode on the selected system. The
mode lamp above the switch on the
MSP and the remote repeater SCAS
ON annunciator will illuminate to ver-
ify that the selected flight computer
has recognized the button push.
The SCAS (Stability Control
Augmentation System) mode pro-
vides rate damping. It may be
referred to as a damper system that
TEST/BRT/DIM (AFCS LAMP
TEST)
Moving the TEST/BRT/DIM Switch,
located on the overhead panel below
the Emergency Bus 1 Breakers, to
the test position will invoke an AFCS
test function that will turn on the
annunciators in the KMS 541 Mode
Select Panel. These annunciations
shall remain on as long as the switch
is held in test position up to a maxi-
mum of 15 seconds. This lamp test
function can be invoked any time
desired by the pilot and has no effect
on mode operation. An automatic
lamp test function is performed upon
power up of the Mode Select Panel
and will turn on all MSP annunciators
for approximately 2 seconds immedi-
ately after power is applied. These
annunciators may also be turned on
by a special test bit from the FCC
during part of its preflight testing. See
Bell Helicopter 430 Flight Manual for
other functions activated by this
switch in the test position.
SCAS
SCAS ON
ı
AP SCAS
SCAS &
AP PWR 2
OFF
SCAS &
AP PWR 1
OFF
KMS 541 SCAS/AP Mode Select Panel
TEST
DIM
B
R
T
SCAS/AP Annunciators
There are nine annunciators for the
system available on the IIDS
(Integrated Instrument Display
System), AFCS DISC (red), 1 SCAS
and SCAS 2 (yellow), 1 AP and AP 2
(yellow), AFCS PIT (yellow), AFCS
ROL (yellow), AFCS YAW (yellow),
and AUTOTRIM (yellow). The SCAS
(1)/(2) and AP (1)/(2) failure annunci-
ators will be illuminated any time
prior to preflight test being per-
formed, after a major system failure

Normal Operation Normal Operation
12 13
June 15, 1999 006-18081-0000
006-18081-0000 March 27, 1998
is stabilizing the helicopter against
outside disturbances and thereby is
augmenting the pilot effort. The
SCAS mode is designed so that heli-
copter attitude changes caused by
pilot control inputs are not signifi-
cantly counteracted by the stability
augmentation system. Only heli-
copter motions caused by outside
disturbances are counteracted.
Some amount of SCAS counterac-
tion is designed into the system for
better pilot feel in the Bell 430.
AP Mode
The autopilot (AP) push-button
engages the pitch, roll, and yaw axes
of the selected system and provides
trim follow-up for those axes.
Momentarily pressing the AP button
on the Mode Select Panel will acti-
vate this mode. The mode lamp
above the switch on the MSP and
the remote repeater AP ON annunci-
ator will illuminate to verify that the
selected flight computer has recog-
nized the button push. The Force
Trim system power for selected sys-
tem must be on and Force Trim sys-
tem not overpowered (detent
switches not activated on primary
system) for this mode to engage.
Autopilot mode will provide com-
mands to maintain the current pitch
attitude and heading. If the roll atti-
tude is not level upon AP engage-
ment, the autopilot will command a
back to the attitude existing at the
time that the pilot intervened.
Alternatively, attitude hold com-
mands may be modified by moving
the Cyclic mounted Beep Trim (CBT)
switch in the appropriate direction.
The yaw axis augments rotorcraft
stability by opposing uncommanded
yaw motion and providing ball cen-
tering. The yaw axis also provides
turn coordination and yaw trim (using
lateral acceleration). Lateral acceler-
ation is used by the system to pro-
vide the described functionality any-
time that the acceleration sensor is
valid. Loss of #1 hydraulic system
automatically disconnects the flight
control system from the yaw axis. In
case of #1 hydraulic power loss, con-
sult the Bell 430 Rotorcraft Flight
Manual for the procedures specified
for AFCS yaw axis operation.
Lateral Command Control
Activated by the Cyclic Beep Trim
(CBT) switch when the AP mode is
on, Lateral Command Control modi-
fies the autopilot’s reference roll atti-
tude. When Lateral Command
Control is used, the aircraft will be
commanded to follow the pilot’s or
copilot’s input to roll left or roll right. If
within 6° of level flight when the
switch is given a momentary push
the first click will yield 6° of bank in
respective direction. If greater than
6° of bank in either direction a
momentary push will result in 1° per
click. If the switch is pressed continu-
ously the system will command a
constant roll rate until the beep trim
switch is released. Upon release of
the CBT switch, the autopilot will
command the aircraft to maintain the
existing roll attitude. Roll attitudes of
less than six degrees of bank will
cause the autopilot to revert to com-
mands for roll-level with heading
hold. The AFCS is designed with
absolute attitude limits and rate lim-
its. During fly through or other
modes of operation , the aircraft atti-
tude/rate must be less than + or -
45°/15° per second in roll and + or -
15°/10° per second in pitch and 15°
per second in yaw for the AP mode
to remain engaged. If these limits
are exceeded the autopilot will auto-
matically disconnect.
level attitude and maintain the head-
ing at the time the aircraft rolls level.
Desired roll and pitch attitudes may
be selected by several methods.
With the autopilot engaged the pilot
can manually adjust the attitude of
the helicopter by pressing and hold-
ing depressed the Force Trim
Release (FTR) switch on the cyclic
while repositioning the helicopter to
the desired attitude. Upon release of
the FTR, the autopilot will provide
commands to maintain the target
pitch and roll attitude if greater than
6°. If the roll attitude is less than 6°
the system will return to roll level atti-
tude and hold the existing heading.
While the Autopilot is engaged the
pilot may press the FTR switch,
manually move the controls to fly the
aircraft to a new attitude and release
the FTR switch and cyclic. The sys-
tem will then hold this new attitude in
pitch and roll if greater than 6
degrees. If less than 6 degrees
bank angle the system will roll wings
level and assume the new heading.
On the primary system the pilot may
momentarily fly the aircraft manually
at any time (via the Fly Through
mode with detent switch activation).
When detents are activated the sys-
tem will temporarily revert to SCAS.
After release of the cyclic (over-
power force is removed and detent
switches not activated) the autopilot
will return to attitude hold (AP
annunciated), and fly the aircraft
AFCS DISC
CYCLIC GRIP SWITCHES
CBT
FTR
AP
AP ON

SCAS/Autopilot Disconnect
The cyclic mounted dual contact
(separate power, primary/secondary)
AFCS DISC switch when pushed
disconnects the selected AP and/or
SCAS mode if engaged. This switch
provides the pilot or copilot a quick
and easy means to disconnect either
of these two control coupled modes
of the selected system.
Force Trim Release (FTR)
The cyclic FTR switch is a double
pole single detent switch interrupting
Force Trim 1 Power when the pri-
mary system is selected and inter-
rupting Force Trim 2 Power when
the secondary system is selected.
Switch actuation allows the pitch, roll
and yaw clutches to be released for
free cyclic and anti-torque pedal
movement. Pushing and releasing
the FTR switch when the autopilot
mode is on (attitude hold), causes
the system to synchronize its refer-
ence attitude and heading with the
present helicopter attitude and head-
ing. When the FTR switch is
pressed, the AFCS will temporarily
revert to SCAS (when AP is
engaged) and the trim servo mag-
netic clutches will release eliminating
the artificial feel system and allowing
the pilot or copilot free movement of
the cyclic. When the switch is
released the AP and trim clutch re-
engages. The Force Trim System
Power must be on to the selected
system for the AP mode to engage.
(Also the Force Trim Detent
switches, in the force feel system,
must not be activated for the primary
AP mode to engage).
Normal Operation
15
006-18081-0000 March 27, 1998
Normal Operation
14
March 27, 1998 006-18081-0000
FTR
Activating Discrete or Continuous Lateral Command has the following effect
upon the command reference for autopilot operation:
Pitch Command Control
Using the same cyclic beep switch
as mentioned in the previous para-
graph, the autopilot’s reference pitch
attitude can be modified by moving
the pitch command switch fore or aft.
Moving the switch forward adjusts
the helicopter’s pitch attitude down-
ward, while moving it aft adjusts the
attitude upward.
Activating Discrete or Continuous Pitch Command has the following effect
upon the command reference for autopilot operation:
Autopilot Lateral Command Values
Discrete Command System Response
Roll Attitude If within ± 6° of level flight: First Click=6°,
Subsequent=1° per click
If greater than ± 6° of level flight: Each
click=1° per click
Continuous Command
Roll Attitude Roll Rate of 7° per second
CBT
Autopilot Pitch Command Values
Discrete Command System Response
Pitch Attitude 0.5° per click
Continuous Command
Pitch Attitude Maintains constant. acceleration profile
of 0.1 g or 2° per second whichever is
less until release
AFCS DISC

Normal Operation
16
March 27, 1998 006-18081-0000 17
KFC 500
Flight Director
Normal Operation
006-18081-0000 March 27, 1998
Yaw Force Trim Release
A collective mounted Yaw ForceTrim
Release switch (Yaw FTR) is pro-
vided for the primary system only
(Force Trim power # 1). If the Force
Trim System # 1 is on and primary
system selected, depressing this
switch releases the yaw clutch
(AFCS yaw axis will revert to SCAS
if engaged), allowing free anti-torque
pedal movement. The AFCS will
annunciate SCAS under this condi-
tion until the Yaw FTR switch is
released.
YAW
FORCE
TRIM
RELEASE

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18 006-18081-0000
March 27, 1998 19
Normal Operation
006-18081-0000 March 27, 1998
RADIO
ICS
FOOT
SW
RADIO
ICS
FOOT
SW
FORCE
TRIM 1
OFF
AP ON
SCAS ON
FORCE
TRIM 2
OFF
AP
1 2
PIC
R
ı
APRHDG
ALT
BL
IAS
AP FD
NAV
VS
SCAS
1
KDC 481
KCP 520
ı
KCP 520
ı
Primary KRG 333
Rate/Acceleration Sensor
Primary
KCP 520
Flight
Computer
KMS 541
Mode Selector
KCS 305 Compass
Trim Actuator
Primary Pitch
Linear Actuator
Control Position
Synchro
Cyclic
Switches
PITCH
ROLL
YAW
Collective
Switches
Primary KVG 350
Vertical Gyro
IIDS
Control Position
Synchro
Control Position
Synchro
Collective Control
Position Synchro
Trim Actuator
Primary Roll
Linear Actuator
Trim Actuator
Linear Actuator
SCAS/AP Remote
Switches/Annunciators
MAN
CW
AUTO
CCW
-
+
KSG105
1
DIRECTION
OFFLIGHT
Secondary
KCP 520
Flight
Computer
Secondary KRG 333
Rate/Acceleration Sensor
DIRECTION
OFFLIGHT
Secondary KVG 350
Vertical Gyro
Secondary Pitch
Linear Actuator
Secondary Roll
Linear Actuator
SCAS &
AP PWR 2
OFF
EFIS PWR
PLT
OFF
EFIS PWR
COPLT
OFF
SCAS &
AP PWR 1
OFF
Display
System
KDC 481T Air Data
Computer 0
2
3
4
5
6
7
8
9ALT
VS ALT
1000FT/MIN
VS23
21
1
.5
.5
0
UP
DN
IN HG HPa DEN ALT
SEL
VS
1,160
30.08 1,700
1
ENG SEL
ı
BARO
U
P
S
H
E
T
S
T
SEL
U
P
L
L
V
S
3
ALT
ALERT
KAV 485
Altimeter/VSI
Navigation
Receivers
AFCS
GROUND
TEST
KFC 500 Dual SCAS/Autopilot/Single Flight Director System Block Diagram

Yaw Force Trim Release
A collective mounted Yaw FTR
switch is provided for the primary
system only (Force Trim power # 1).
If the primary system is selected with
autopilot mode engaged and Force
Trim System # 1 power on, pressing
the Yaw FTR switch will release the
yaw clutch (AFCS yaw axis will
revert to SCAS if engaged), allowing
free anti-torque pedal movement.
The AFCS will annunciate SCAS
under this condition until the Yaw
Force Trim Release switch is
released. In flight director equipped
aircraft, if the autopilot is engaged,
upon release of the switch the
autopilot will command ball centered
flight if above 50 KIAS.
Normal Operation Normal Operation
20 21
March 27, 1998 006-18081-0000
006-18081-0000 June 15, 1999
Flight Director Operation
Modes of Operation
The KMS 540 Mode Select Panel
provides control and annunciation of
the KFC 500’s primary (#1) sys-
tem’s Flight Director modes as well
as the selected system’s Autopilot
and SCAS modes. The Autopilot and
SCAS modes operate the same as
previously described in the
SCAS/Autopilot section. To activate
flight director modes using the Mode
Select Panel, momentarily press the
desired button. The corresponding
mode lamp above the push-button
will illuminate and the mode annunci-
ation on the Electronic Attitude
Indicator (EADI) will appear indicat-
ing that the FCC has coupled the
mode. Alternatively, to deactivate a
flight director mode when activated,
momentarily press the respective
push-button. The illumination level of
the annunciator lamps on the mode
The following section provides an explanation of the normal operating proce-
dures for the flight director functions of the dual KFC 500 SCAS/AP System
when equipped with Flight Director. The Flight Director functions are only
available when the primary (#1) system is selected. If Flight Director modes
are engaged when secondary system is selected they will be canceled. Flight
Director modes will also be canceled and or not allowed when AP coupled
and a roll or pitch trim failure has occurred. Dual system SCAS/AP operation
when not coupled to the Flight Director is identical to that of the basic dual
SCAS/AP System, described in the proceeding section, with the following
exceptions:
SCAS/AP Operation
(Flight Director installed)
When the Flight Director is included
in the system a central air data sys-
tem is also installed. The air data
system allows the AFCS to provide
additional functionality in the yaw
axis plus improved performance with
airspeed gain scheduling in all axes.
The yaw axis, as described in the
previous section, augments rotor-
craft stability by opposing uncom-
manded yaw motion (rate damping -
keeps nose from moving), ball cen-
tering, and also provides turn coordi-
nation as well as yaw trim (using lat-
eral acceleration). With the air data
system installed Lateral acceleration
is used by the system to provide the
described functionality when the
acceleration sensor is valid, the
AFCS is receiving valid airspeed
information from the air data, and the
aircraft is flying at an indicated air-
speed greater than 50 knots. When
the aircraft is flying below 50 KIAS or
when air data is invalid ball centering
and turn coordination is inhibited.
During this time the AFCS yaw axis
will provide yaw rate damping only.
ı
APRHDG
ALT
BL
IAS
AP FD
NAV
VS
SCAS
KMS 540 Flight Director Mode Select Panel
selector is adjusted automatically by
a photocell located on the face of the
unit. If Autopilot is coupled to the
Flight Director when a loss of valid
data from required sensors for the
default Flight Director mode occurs,
the system will revert to basic AP
mode. The button nomenclature
back lighting is controlled by the
pedestal dimmer control on the over-
head panel.
If the Bell 430 with dual KFC 500
system is equipped with copilot
EFIS, a Pilot in Command (PIC)
switch will be located above the
KMS 540 Mode Select Panel. This
SCAS &
AP PWR 2
OFF
EFIS PWR
PLT
OFF
EFIS PWR
COPLT
OFF
SCAS &
AP PWR 1
OFF
YAW
FORCE
TRIM
RELEASE
PIC
L R

Normal Operation Normal Operation
22 23
June 15, 1999 006-18081-0000
006-18081-0000 June 15, 1999
switch determines which pilot is in
control of the single KFC 500 flight
director. L(left) or R(right) will be lit
depending on which position the
switch is in. The KFC 500 will
engage in only one horizontal and
one vertical tracking mode at a time.
Flight Director armed modes do not
conflict with active (capture or track)
modes. For example, selecting a
new course in the NAV ARM mode,
or a new altitude in Altitude Select,
does not affect active tracking modes
such as Heading or Vertical Speed
Hold. It is often useful to engage a
separate mode to provide flight guid-
ance to the capture point for a
course or altitude pre-selected in an
Arm mode. The Flight Director
System will transition automatically to
capture the armed mode, canceling
the previous selected mode.
Examples of this operation are
described in the Operational
Examples section of this Pilot’s
Guide. To cancel a flight director
mode engaged in either capture or
tracking operations, either select an
alternate tracking mode or press and
release the engaged mode’s push-
button on the mode select panel. The
latter method also cancels modes
while in their Arm phases. Go
Around is an exception. The collec-
tive mounted push-button provides
the engage function only. To discon-
nect Go Around select another pitch
mode. The Flight Director provides
the basic modes - Roll Attitude
level/Heading Hold and Pitch
Attitude Hold. These default modes
provide basic flight stability and
serve as safety backups in the event
that the flight director cancels an
active mode due to loss of a required
navigation signal or sensor failure.
Engaging the KFC 500 in any track-
ing mode automatically cancels the
corresponding default mode for that
particular axis.
Pitch Attitude Hold & Roll
Attitude Hold (FD)
In the absence of any other selected
Flight Director modes, the system
will provide commands to maintain
current pitch attitude and establish a
level roll attitude. When roll attitude
approaches six degrees or less bank
angle, the flight director will provide
commands to maintain constant
heading.
Desired roll and pitch attitudes may
be selected by several methods. If
the Flight Director is coupled to the
autopilot (AP ON), the helicopter’s
attitude may be manually adjusted
by pressing and holding the Force
Trim Release (FTR) switch on the
cyclic while repositioning the heli-
copter to the desired attitude. Upon
release of the FTR switch, the Flight
Director will provide commands to
maintain the new target pitch and roll
attitude if greater than 6°. If the roll
attitude is less than 6° the system
will provide commands to return to
roll level and hold the existing head-
ing. Alternatively, Attitude Hold com-
mands may be modified by moving
the Cyclic mounted Beep Trim
(CBT) switch in the appropriate
directions. If a target roll attitude of
six degrees or less is selected, the
Flight Director will provide com-
mands to maintain the helicopter’s
current heading. Selecting any hori-
zontal or vertical tracking mode can-
cels Roll Attitude/Heading Hold or
Pitch Attitude Hold, respectively.
Either mode may be used in con-
junction with any Arm mode to pro-
vide flight guidance for course or alti-
tude intercepts. Pressing the FD
switch without any FD modes
engaged will engage the basic
default modes. Pressing FD when
any modes are engaged will disen-
gage all Flight Director modes and if
AP is engaged system will revert to
basic AP Attitude Hold modes.
Lateral Command Control
Activated by the Cyclic Beep Trim
(CBT) switch when the Flight
Director is on, Lateral Command
Control modifies the system’s refer-
ence attitude during operations in
Roll Attitude Hold. Operating Lateral
Command Control does not affect
Capture/Track in Navigation (NAV)
mode or Capture/Track in Approach
(APR) mode. To operate Lateral
Command Control with Navigation or
Approach mode in track, the mode
must first be deselected by pushing
the button on the Mode Select
Panel. When the system mode is roll
level or bank angle hold (FD and/or
AP) and the Lateral Command
Control is used, the aircraft will be
commanded to follow the pilot’s
input to roll left or right. If the switch
is held continuously the system will
command a constant roll rate until
the beep trim switch is released. If
the switch is pushed discretely, the
first push will yield 6° of bank if heli-
copter is level and 1° of bank for
each additional push or click. If heli-
copter is greater than +/- 6° the first
click and each subsequent click will
yield 1°. Upon release of the CBT
switch, the flight director will com-
mand the aircraft to maintain the
FD
☛

Normal Operation Normal Operation
24 25
June 15, 1999 006-18081-0000
006-18081-0000 June 15, 1999
existing roll attitude if greater than 6°.
Roll attitudes of less than six degrees of
bank will cause the Flight Director to
revert to commands for roll-level flight
with heading hold. When heading select
(HDG) mode is engaged, the heading
bug on the EHSI may be re-positioned
to a new heading using the CBT switch.
Moving the CBT switch to the left will
slew the heading bug counterclockwise
while movement to the right will slew the
bug clockwise. The AFCS is designed
with absolute attitude limits and rate lim-
its. During fly through or other modes of
operation , the aircraft attitude/rate must
be less than + or - 45°/15° per second in
roll and + or - 15°/10° per second in pitch and 15° per second in yaw for the
AP mode to remain engaged. If these limits are exceeded the autopilot will
automatically disconnect.
Activating Discrete or Continuous Lateral Command has the following effect
upon command values in flight director operations:
Vertical Command Control
Using the same cyclic switch as
mentioned in the previous para-
graph, vertical commands can be
modified by moving the CBT switch
fore or aft. Operation of the Vertical
Command Control depends on the
flight director mode engaged.
Flight Director Lateral Command Values
Discrete Command System Response
Roll Attitude Hold First Click=6°, Subsequent=1° per click
Heading Select 1° Heading Bug novement per click
Continuous Command
Roll Attitude Hold Roll Rate of 7° per second
Heading Select 16° Heading Bug movement per second
Moving the switch forward adjusts
the helicopter’s pitch attitude down-
ward, while moving it aft (rearward)
adjusts the attitude upward.
Activating Vertical Command has
the following effect on flight director
vertical modes: has no effect on ALT
ARM (altitude preselect arm), ALTC
(altitude capture), GS (glideslope),
GA (go around), overspeed protec-
tion (nose down or increasing air-
speed), and autolevel. To use
Vertical Command Control when
these modes are engaged, first des-
elect the mode. Vertical Command
will trim or modify the reference for
PIT (pitch attitude hold), ALT (alti-
tude hold), VS (vertical speed hold),
IAS (indicated airspeed hold) and
overspeed protection (nose up or
decreasing airspeed). Attitude Hold,
Altitude Hold, Indicated Airspeed
Hold, and Vertical Speed Hold will
remain coupled throughout Vertical
Command (CBT) operation.
CBT
Flight Director Vertical Command Values
Discrete Command System Response
Pitch Attitude 0.5° per click
Altitude Hold 10 feet per click
Indicated Airspeed Hold 1 Knot per Click
Vertical Speed Hold 100 feet per minute per click
Continuous Command
Pitch Attitude Maintains constant. acceleration profile
of 0.1 g or 2° per second whichever is
greater until released and then holds the
attitude at release
Altitude Hold 50 feet per second until release
Indicated Airspeed Hold 5 knots per second until release
Vertical Speed Hold 300 feet per minute per second until
release
AFCS DISC
FD OFF
CYCLIC GRIP SWITCHES
CBT
FTR
Activating Discrete or Continuous Vertical command Control has the following
effect upon command values in flight director operations:

Force Trim Release (FTR)
When the Flight Director is active,
and coupled to the autopilot, the
Force Trim Release switch (FTR)
allows the crew to synchronize flight
director commands in pitch and roll
to the actual helicopter position.
When the selected mode for flight
director is pitch attitude hold, altitude
hold, airspeed hold, vertical speed
hold, roll level/heading hold, or roll
attitude hold, pushing FTR will cause
a new flight director reference to be
established upon release of the
switch. All commands will then be
directed to hold this new reference. If
the AFCS is in APR mode and GS
track, pressing the FTR will have no
effect. If the AFCS has reverted to
overspeed protection mode, the FTR
switch is pushed and held, and the
pilot manually reduces airspeed to a
value below VNE, upon FTR release
the system will revert to the previ-
ously engaged pitch mode. Pressing
the FTR switch will have no effect on
ALT ARM, ALT capture, Go Around,
Autolevel, HDG select, NAV or APR
modes including GS. Upon release
of the FTR switch, the flight director
will provide commands to return to or
maintain the steering required for
these modes, while FTR is held
pressed the commands displayed
will be synchronized to the heli-
copter’s reference.
Flight Director Off
When the Flight Director Off (FD
OFF) switch on the cyclic is momen-
tarily depressed, the flight director
deactivates and the system reverts
to AP roll level attitude or heading
hold and pitch attitude hold if the
autopilot was previously engaged.
Subsequent activation of the flight
director modes may be accom-
plished by depressing the appropri-
ate Mode Select Panel push buttons
or by arming altitude select or
engaging vertical speed hold from
the Altitude/Vertical Speed Indicator
when primary system is selected.
Normal Operation
27
006-18081-0000 March 27, 1998
Normal Operation
26
June 15, 1999 006-18081-0000
FTR
Go Around
Pressing the GO AROUND push
button on the collective switch box
activates the Go Around mode in
which the flight director commands a
750 feet per minute climb and a roll
level attitude. Any horizontal tracking
mode may be subsequently re-
engaged without cancelling the Go
Around mode. Go Around mode can
only be canceled by selecting
another vertical mode (i.e. ALT, IAS
or VS).
FD OFF
GO
AROUND

Normal Operation Normal Operation
28 29
March 27, 1998 006-18081-0000
006-18081-0000 June 15, 1999
Heading Select (HDG)
Depressing the HDG push-button on
the mode select panel activates
Heading Select mode. This mode
will provide flight director commands
to track the heading bug on the
EHSI. The annunciator above the
switch on the mode select panel illu-
minates and “HDG” is displayed, in
green, on the EADI when the head-
ing select mode is activated.
Activating heading select cancels
any other lateral tracking mode. If
the heading select mode is active,
depressing the HDG push-button will
deactivate the mode and revert the
flight director back to the default
mode of roll level and heading hold.
Upon manual deactivation, the
annunciator lamp above the HDG
push-button and the green HDG
annunciation on the EADI will flash
for five seconds. This flash
sequence will terminate upon reacti-
vation of HDG or another lateral
mode. Continuous flashing of the
annunciator lamp above the push-
button and the flashing of and
changing color from green to yellow
of the HDG annunciation on the
EADI indicates loss of a sensor
required to hold the selected head-
ing (e.g. invalid magnetic heading,
invalid selected heading from EHSI).
The annunciations will continue
flashing until the HDG push-button is
activated (pilot acknowledgment of
mode loss) or another lateral mode
is selected.
Bank Angle Limit (BL)
The Bank Angle Limit mode allows
the maximum commanded bank
angle to be selected by the pilot. The
default value, 20°, is obtained at
power-up. The pilot may select 15°,
10°, 25° and then 20° again by
pressing the BL button until the
desired maximum bank is achieved.
The selected maximum bank angle
is annunciated on the EADI as BL15,
BL10, or BL25. The default value of
20° is not annunciated. In the
approach phases of flight, bank
angle limiting is disabled to provide
optimized approach guidance by the
flight director. All approach captures
are made with a maximum bank
angle of 20°. If lesser bank angles
are desired, the pilot may use the
heading select mode (move the
heading bug slowly) to capture the
localizer and then depress the APR
push-button to activate Approach
mode when tracking inbound on the
appropriate course.
When the flight director is coupled to
a long range navigation sensor like a
navigation management system
(NMS), GPS, etc. (i.e. GNS-X, KLN
90) that has a composite steering
output, the long range navigation
sensor has complete control of bank
Autopilot/Flight Director Mode Annunciation
AP HDG IASNAV ALT
120 KT
20 20
BL25 GS
FD
1. Bank Angle Limit
2.Autopilot Engaged Annunciator
3. Armed Lateral Mode
4. Active Lateral Mode
5. Command Reference Value
6. Active Vertical Mode
7. Armed Vertical Mode
8. Flight Director Flag
KMS 540 Flight Director Mode Selection
HDG
☛
BL
☛
1
32 4 5 6 7
7
8

Normal Operation Normal Operation
30 31
June 15, 1999 006-18081-0000
006-18081-0000 June 15, 1999
angles up to 25° unless a bank limit
is selected. Bank limiting is allowed
in this situation and can affect track-
ing performance. If improved Long
Range NAV tracking is desired, set
the bank limit to the default value
(20°).
Navigation Mode (NAV)
The NAV lamp illuminates and
“NAV” is displayed on the EADI
when the NAV mode is activated by
depressing the NAV push-button on
the KMS 540 Mode Select Panel.
When the NAV mode is selected by
the NAV push-button and course
needle deflection is greater than
50% full scale needle deviation, the
NAV ARM (NAV white on EADI)
mode is activated and allows a com-
patible lateral mode to be used to
intercept the desired course or track.
If the aircraft’s deviation from the
selected course centerline is less
than 50% full scale needle deviation,
or if the rate of closure with the new
course is sufficiently high, the flight
director initiates the NAV capture
(NAV green on EADI) sequence
immediately. If the NAV mode is
active, depressing the NAV push-
button will deactivate the mode and
revert the flight director back to the
default mode of roll level and head-
ing hold. Upon manual deactivation,
the annunciator lamp above the NAV
push-button and the green NAV
annunciation on the EADI will flash
for five seconds. This flash
sequence will terminate upon reacti-
vation of NAV or another lateral
mode.
Continuous flashing of the annunci-
ator lamp above the push-button and
the flashing of and changing color
from green to yellow of the NAV
annunciation on the EADI indicates
loss of a sensor required to capture
or track the selected navigation sen-
sor (e.g. invalid navigation receiver,
invalid selected course from EHSI).
The annunciator continues to flash
until the NAV push-button is pushed
(pilot acknowledgment of mode loss)
or another lateral mode is selected.
Approach Mode (APR)
The APR lamp illuminates and
“APR” is displayed on the EADI
when the APR mode is activated by
depressing the APR push-button on
the KMS 540 Mode Select Panel.
When the APR mode is selected by
the APR push-button and course
needle deflection is greater than
50% full scale needle deviation, the
APR ARM (APR white on EADI)
mode is activated and allows a com-
patible lateral mode to be used to
intercept the desired course or track.
If the aircraft’s deviation from the
selected course centerline is less
than 50% full scale needle deviation,
or if the rate of closure with the new
course is sufficiently high, the flight
director initiates the APR capture
(APR green on EADI) sequence
immediately. If the APR mode is
active, depressing the APR push-
button will deactivate the mode and
revert the flight director back to the
default mode of roll level and head-
ing hold. Upon manual deactivation,
the annunciator lamp above the APR
push-button and the green APR
annunciation on the EADI will flash
for five seconds. This flash
sequence will terminate upon reacti-
vation of APR or another lateral
mode.
The flight director may initiate
turn commands before the course
deviation indicator displays move-
ment.
Selecting the Approach mode after
the aircraft has already passed the
point at which Approach Capture
normally would begin may result ini-
tially in course overshoot due to the
flight director’s roll command limits.
The KFC 500 discriminates automat-
ically between LOC, LOC back
course, VOR, LNAV, and GPS sen-
sor types. The KFC 500 uses the
sensor type information to determine
if BC (back course) is an appropriate
mode; after that front course/back
course selections are determined by
the relative angle between the air-
craft’s heading and the course
selected on the EHSI. Intercept
angles between 0° and 105° cause
the KFC 500 to select front course
(LOC is selected sensor on EHSI).
Angles between 106° and 180°
cause the flight director to command
back course interception and track-
ing (LOC selected sensor on EHSI).
It is essential that the course
selector arrow on the EHSI dis-
play always be aligned with the
ILS front course. When flying
inbound on a Backcourse
Approach, the selected course
should be in the opposite direc-
tion of the helicopter’s heading.
Failure to align the course arrow
properly will result in erroneous
front/back course selection by the
flight director.
The flight director automatically
engages Glideslope Arm (GS white
on EADI), Capture and Track (GS
green on EADI) sequences during
ILS front course approaches. The
localizer must be captured in order
for glideslope to ARM and then cou-
ple. Glideslope coupling is inhibited
during back course procedures.
Any horizontal tracking mode may
be employed during Approach Arm
phases and will cancel automatically
upon initiation of Approach Capture
and Track. Any vertical mode may
be used prior to glideslope capture
or track and will automatically cancel
upon initiation of glideslope capture.
Activation of Approach Capture will
automatically incorporate the default
maximum commanded bank angle,
20°, for optimum performance.
Continuous flashing of the annunci-
ator lamp above the push-button and
the flashing of and changing color
from green to yellow of the APR (i.e.
VOR source) or LOC/GS (i.e. ILS
source) annunciation on the EADI
indicates loss of a sensor required to
capture or track the selected naviga-
tion sensor (e.g. invalid navigation
receiver, invalid selected course
from EHSI). The flashing annuncia-
NAV
☛
APR
☛