T-6A INSTRUMENT NAVIGATION
constantly changing, prior experience with the airport does not guarantee reception at all times,
and RAIM availability should always be checked.
For the purpose of alternate field selection, a compatible and
operational non-GPS approach shall exist at the alternate airport.
The SuperNAV 5 page has been specifically designed to provide most of the functions needed
for non-precision approaches. This page provides an interface that presents pertinent navigation
information, a way to access the flight plan, and a graphic presentation of the present position
relative to the flight plan waypoints. You will find this page to be very useful in conducting non-
precision approaches. It can be accessed by selecting the NAV 5 page on both the left and right
side of the GPS console.
When conducting GPS approaches, it is important to understand the differences between the
OBS and LEG modes of operation of the KLN 900. LEG mode provides automatic waypoint
sequencing and navigation to the active waypoint via a direct routing from your present position.
LEG mode is used when flying along a flight planned routing or along a FAC where auto
sequencing of waypoints is required. The OBS mode provides no automatic sequencing between
waypoints. OBS mode only provides navigation to the active waypoint by way of the course.
OBS mode is used when:
Conducting a procedure turn outbound.
When intercepting a FAC via radar vectors.
When given radar vectors to the FAF, select OBS mode on the
GPS, select the FAF as the active waypoint, and set the FAC in the
CDI. Once established on the inbound course and prior to the
FAF, reselect LEG mode on the GPS.
802. COURSE SENSITIVITY
CDI sensitivity related to GPS equipment varies with the mode of operation and the type of
equipment (refer to your flight manual). Unlike traditional ground-based NAVAIDs, GPS
course sensitivity is normally linear regardless of the distance from the waypoint. Typically, the
following modes provide the indicated CDI scaling:
8-2 GLOBAL POSITIONING SYSTEM