TM 1-1510-218-10
3C-146
To sequence past the FAF into the GPS
approach, the aircraft track must be within 90° of the
final approach course and current leg course, and
within 2 nm of the FAF waypoint. If not, the FMS will
inhibit sequencing past the FAF waypoint and continue
guidance for the inbound course to the FAF until the
aircraft is maneuvered into the final approach
configuration.
Once the aircraft sequences past the FAF
waypoint, the sequencing mode of the FMS will switch
to manual sequencing (MAN). Sequencing beyond the
MAP is inhibited until the MAP is passed or a direct–to
is executed to a missed approach waypoint.
(a) DME Arc Guidance. If a published
GPS overlay approach contains a DME arc leg, it is
indicated by a D attribute on the right side of the Flight
Plan page for the waypoint at the termination of the
DME arc leg. The HSI and flight director/autopilot
guidance will follow the arc and the distance display on
the HSI, while on that leg will be the direct distance
from the arc to the waypoint. The flight plan leg
switching is normal. Refer to Figure 3C–93.
A Direct–To the endpoint of a DME arc, when it
is not the active waypoint, will cause the FMS to
intercept the arc along the DME arc leg. To intercept a
Direct–To course directly to the DME arc endpoint
waypoint without intercepting the arc, select Direct–To
the DME arc endpoint again which will override the
DME arc leg intercept.
(b) Course Reversal Guidance. On
selected GPS approaches, a published procedure turn
may be defined for execution in the approach
procedure. The FMS performs a course reversal
procedure with standard holding pattern entry logic to
execute the procedure turn. When the approach is
inserted into the flight plan, the course reversal will be
automatically enabled for execution. A C attribute will
be identified next to the GPS approach IAF waypoint
when the course reversal is enabled.
Execution of the course reversal will follow
standard holding pattern entry logic. The definition of
the course reversal procedure uses the holding pattern
definition for the IAF waypoint. To review the course
reversal definition, press the line select key adjacent to
the C attribute on the Flight Plan and Flight Plan
Waypoint pages to access the Holding Pattern page
for the IAF waypoint.
The operator can modify the course reversal
size, duration, and length, when in the Holding Pattern
page, but the course reversal course and turn direction
cannot be changed. Changes to the course or turn
direction will automatically disable the course reversal
procedure. When the course reversal is re-enabled,
the published course and turn direction will be restored
to the published definition.
Figure 3C-93. DME Arc Flight Path
