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System Operation
3-37
GNS-XL Flight Management System
Rev. 1
Jul/98
EXECUTING APPROACHES
WARNING: When entering PTs or HP airspace at high speed the
FMS may not constrain the airplane from violating maneuvering
airspace. Pilots are responsible for procedural compliance.
When the aircraft is within 30NM of the airport, the system will go into
the Approach Armed mode. The CDI sensitivity will change from
5.0NM full scale deflection to 1.0NM full scale deflection. At this point
the aircraft may bank slightly due to increased roll steering gains.
Anytime the TO waypoint is part of an Approach Procedure, the SXTK
field is disabled so that no parallel course can be entered.
The system is capable of executing GPS, GPS Overlay, NDB, RNAV,
CIRCLING, and VOR approaches only. No LOC, ILS or MLS capabili-
ty is available.
If RAIM is not available at 2NM from the FAF, an APPROACH WARN
message will appear on the SYSTEM MESSAGES Page. Also, the
HSI flag will be set invalid. At this point the appropriate missed
approach procedures should be executed. The system will remain in
the Approach Mode and the discrete APPROACH annunciator will
remain illuminated until the HSI is set valid. To set the HSI valid, can-
cel the Approach on the SYSTEM MESSAGES Page by pressing the
ENT Key.
The system will not display any interim waypoints between the FAF
and the MAP, even though a waypoint may be shown on the
approach plate. The system may not give vertical guidance to the
interim waypoint. Pilots are responsible for procedural compli-
ance.
NOTE: If the MAP is abeam or beyond the threshold, or the approach
is a circling approach, no altitude constraints will be displayed at the
MAP from the database. Constraints may be entered manually.
When the Approach is flown, the system will provide guidance along
the final approach course to the Missed Approach Point.
When initially executing a missed approach procedure, use the
FMS Heading Mode or manually fly the procedure to ensure prop-
er track and turn direction.
NOTE: A “fence” (++++++) separates the Missed Approach
Procedure waypoint from the MAP, the last waypoint of the Approach.
No Auto Leg change (waypoint sequencing) will occur to waypoints
beyond the “fence” (++++++) once the airplane passes the MAP.