BendixKing KFC 500 - Manual (Page 10)

Normal Operation
10 June 15, 1999 006-08769-0000
Normal Operation
11 006-08769-0000 June 15, 1999
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. To activate
the SCAS or AP modes using the
Mode Select Panel, press the
desired push-button. The corre-
sponding mode lamp will illuminate
above the switch. Alternatively, to
deactivate the SCAS or AP mode
when activated, depress the respec-
tive push-button and then release
(The AP mode reverts to SCAS
when deselected).
There is a remote repeater annunci-
ator located above the mode selec-
tor panel. This annunciator will mimic
the annunciators located above the
mode switches on the Mode Select
Panel. The brightness of the annun-
ciator lamps on the mode controller
is adjusted automatically by a photo-
cell located on the face of the unit.
The button nomenclature back light-
ing is controlled by the pedestal dim-
mer control on the overhead panel.
SCAS Mode
Depressing the SCAS button on the
Mode Select Panel will activate the
stability augmentation mode. The
annunciator above the switch on the
MSP and above the MSP on sepa-
rate panel will illuminate to verify that
the 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
is stabilizing the helicopter against
outside disturbances and thereby is
augmenting the pilot effort. The
SCAS mode is designed so that pilot
control inputs which cause helicopter
attitude changes are not significantly
counteracted by the stability aug-
mentation system. Only helicopter
motions caused by outside distur-
bances are counteracted. Some
amount of SCAS counteraction 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 and provides trim follow-up for
those axes. Depressing the AP but-
ton on the Mode Select Panel will
activate this mode. The annunciator
above the switch on the MSP and
above the MSP on separate panel
will illuminate to verify that the flight
computer has recognized the button
push. The Force Trim system must
be on for this mode to operate.
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
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
failure the annunciator will extinguish
if SCAS engaged. An Autotrim fail-
ure indication means that roll or pitch
trim has failed and more attention
will need to be given to see that the
system is kept within the control
authority of the main servo by using
the FTR switch to keep the system
working within its control range. The
non-selected system will annunciate
AP and SCAS Fail annunciation for
single 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 normal power up delay. If this
side is selected then the annuncia-
tion will display the single or multiple
axis failures applicable and clear the
AP and / or SCAS Fail annunciation
if any axis is available for use.
ı
AP SCAS
KMS 541 SCAS/AP Mode Select Panel
AFCS
GROUND
TEST
SCAS &
AP PWR
OFF
SCAS
SCAS ON