Approaches With Procedure Turns

T-6A INSTRUMENT NAVIGATION

CHAPTER EIGHT

NOTE

The GPS system will not automatically sequence to any waypoints

required to execute the missed approach procedure. Automatic

sequencing will cease at the MAP. If a missed approach is

required, the pilot must manually sequence the system to the

MAWP. Press the "DIRECT TO" key followed by the "ENTER"

key, the default WPT will be the MAWP defined in the procedure.

APPROACHES WITH PROCEDURE TURNS

If a procedure turn is required prior to executing the final approach segment, the pilot must

consider whether the approach has a co-located IAF and FAF or not. If an approach has a co-

located IAF/FAF and requires a course reversal (procedure turn), then OBS mode must be

selected prior to executing the outbound leg. Selecting OBS mode disables automatic waypoint

sequencing and allows the inbound course to be dialed into the CDI so it can be intercepted on

the procedure turn inbound. If the aircrew does not select the OBS mode, the GPS will

automatically sequence to the MAWP at the co-located IAF/FAF. On the procedure turn

outbound, make sure the IAF/FAF is still the active waypoint, dial the inbound course into the

CDI, and complete the procedure turn. Once established on the inbound course, select LEG

mode to enable automatic waypoint sequencing. When the IAF and FAF are the same waypoint,

the FAF is automatically made the active waypoint when LEG mode is selected. Be sure to

allow sufficient distance to have a minimum of 2 NM to the FAF prior to selecting LEG mode so

the GPS will transition to the ACTIVE mode when conditions permit.

For procedure turn approaches where the IAF and FAF are not co-located, the IAF must be

overflown to allow the GPS to sequence to the FAF automatically. In this case, if OBS is

selected prior to the IAF, then automatic waypoint sequencing would be disabled and the FAF

would have to be manually selected as the active waypoint. Therefore, only select the OBS

mode once past the IAF instead of just prior to it. Complete the procedure turn outbound in OBS

mode, confirm the FAF is the active waypoint, and dial the inbound course into the CDI. As

before, select LEG mode at a minimum distance of 2 NM from the FAF once established on

final.

In the case that a NoPT route segment is flown, it must be done in LEG mode. OBS mode is not

required for NoPT routings. There are no course reversals in this instance so there is no need to

interrupt auto sequencing. The IAF must, however, be overflown so the FAF sequences

automatically to the active waypoint. Once established on a final course to the FAF, the

approach procedures remain the same as in RVFAC.

ARCING APPROACHES

Arc procedures will only be encountered with overlay approaches, but it must be noted that DME

arc procedures flown with the GPS are significantly different than traditional VOR/TACAN

arcing approaches. DME arc approaches are flown in the LEG mode. Selecting an approach

GLOBAL POSITIONING SYSTEM

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