Climb-out/Enroute
3-9
Whenever VNAV is selected and the aircraft passes the last
waypoint in the flight plan with an altitude constraint, the autopilot
will automatically transition to ALT Hold mode at the last VNAV
waypoint altitude constraint.
If conducting a precision approach in VNAV mode, VNAV will
automatically disengage when the final approach course is
captured. For ILS approaches, the system will almost
simultaneously switch primary nav source so that the aircraft
continues to intercept and follow the glideslope. For precision
WAAS approaches, the system will automatically begin following
the vertical guidance provided by the WAAS approach.
If conducting a non-precision approach in VNAV mode, VNAV will
fly all defined step-down fixes until reaching the leg that contains
the Missed Approach Point, at which time, VNAV will
automatically disengage and the autopilot will transition to Altitude
Hold and hold the altitude of the waypoint just prior to the Missed
Approach Point.
NOTE
VNAV Altitude Constraints on an Airfield
If a flight plan leg altitude constraint is entered for a
flight plan waypoint that is an airport, the default
VNAV target altitude constraint will be 1000’ AGL
and 5 miles prior to the airport. Taking advantage of
this feature can produce a good technique of using
VNAV to enter a VFR pattern including presenting a
Top of Decent marker on the map and a smooth,
controlled entry into the VFR pattern in VNAV mode.
When flying a published missed approach in VNAV mode, all
altitude constraints will be achieved until there are no further
altitude constraints in the procedure. Holding patterns as part of
a published missed approach do not typically have an associated
altitude constraint and, therefore, VNAV will typically
automatically transition to Altitude Hold mode upon entering the
hold.
