BendixKing KFC 500 - Manual (Page 20)

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
☛