II Morrow Inc. Apollo NMC, Operating Manual

Page: 257 / 367

Procedure Turns
A procedure turn is a way of crossing the same waypoint more than
once in order to accomplish a course reversal. First, make sure that
flight plan leg sequencing is suspended. Second, after crossing the
waypoint, set the correct inbound course to intercept. Finally, enable
sequencing when you are established inbound.
In some cases, the NMS will know when a course reversal is required
and will automatically suspend sequencing. This is the case when
during an approach, the FAF is the active waypoint and there is more
than a 70 degree difference between your bearing to the FAF and the
final approach course (FAF to MAP course). In this case the NMS will
automatically suspend sequencing and the
OBS/HLD annunciator
will light.
Note
The only other time the NMS will automatically
suspend sequencing for you is when the active
waypoint is either the Missed Approach Point (MAP)
or the Missed Approach Holding Point (MAHP).
When you know that a procedure turn
or course reversal is required, check the
OBS/HLD annunciator and press the
OBS/HLD button if necessary to
suspend sequencing and to light the
annunciator.
When you cross the waypoint, the TO/FROM flag will change to
“FROM.”
Next, set the desired inbound course by
pressing
DIRECT-TO twice. Set the
desired inbound course with the Large
and Small knobs. Then, press ENT.
241
Operations Approach Procedures
ENT
D
D