BendixKing KFC 500 - Manual (Page 15)

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
APR HDG
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