Pitch Coupled Modes - Honeywell BENDIX/KING KAP 140 Maintenance Manual

2.10.3 PITCH COUPLED MODES

2.10.3.1 VERTICAL SPEED MODE (VS)
The VS mode is the default pitch mode and provides pitch FD commands to hold the reference
vertical speed. The vertical speed reference is initialized to the altitude rate current upon mode
selection. The reference is limited to the certified limits. The VS mode is activated when the AP
is engaged and another pitch mode has not been selected. It is also activated whenever the AFCS
cancels another pitch mode due to invalid sensor(s). Activating VS mode cancels any other
vertical tracking mode. It remains active if an ARM mode is selected (such as ALT ARM) until the
ARM mode is captured. The VS mode can be deactivated by selecting another vertical mode.
When in the VS mode, "VS" is annunciated in the pitch coupled display field.
2.10.3.2 ALTITUDE HOLD MODE (ALT)
The Altitude Hold mode maintains the aircraft altitude at engagement or the reference established
by altitude capture or after engagement (with the UP/DN reference inputs). If baro--correction is
provided, the mode will track baro--corrected altitude. Otherwise, pressure altitude will be used.
The ALT hold mode is activated when the ALT button is pressed and Altitude Hold is not already
active. The ALT hold mode can also occur through automatic capture from the altitude arm mode.
Activating ALT hold cancels any other vertical tracking mode. It remains active if a vertical ARM
mode is selected (GS ARM or ALT ARM) until the ARM mode is captured. The ALT hold mode
can be deactivated by selecting another vertical mode or by pressing the ALT pushbutton again.
When in the ALT hold mode, "ALT" is annunciated in the pitch coupled field. In the event the
baro--correction information is unavailable or becomes invalid, pressure altitude is used.
2.10.3.3 ALTITUDE CAPTURE PHASE
The Altitude Capture phase of Altitude Hold mode provides pitch commands to capture the
selected altitude. Commanded accelerations should not exceed 0.2 g.
2.10.3.4 GLIDESLOPE COUPLED MODE (GS)
The GS coupled mode provides commands to track the glideslope path within the required
approach accuracies. An invalid GS Valid or an invalid NAV Valid during GS coupled mode causes
a reversion to the default pitch mode. The GS coupled mode is activated automatically, as
described in the section titled "Glideslope Arm Mode". The GS coupled mode can be deactivated
by disengaging the AP, by pressing the APR pushbutton, or by selecting another pitch coupled
mode (if not within the forced capture limits on GS deviation).
When in the GS coupled mode, "GS" is displayed in the pitch coupled field. In the event the
glideslope is invalid for 3 seconds, the GS annunciation flashes and the FCC reverts to the pitch
default mode. The flashing of the GS annunciation continues until canceled by selection of
another pitch coupled mode. Upon deactivation of the flashing, the current selected mode(s) is
annunciated.
Revision 2, Dec/2002
CS:15574F02.IDU
BENDIX/KING
KAP 140
Page 2--18