Flight Management System (FMS) - Global Positioning System (GPS)

JOINT ADVANCED MULTI-ENGINE T-44A

410.

Flight Management System (FMS) - Global Positioning System (GPS).

A. The Future.

Many of the current radio navigation aids in use today will be slowly phased out in the foreseeable

future. According to the 1999 Federal Radionavigation Plan (FRP), current NAVAIDS such as

TACAN, VOR, NDB and ILS will begin to disappear around the year 2008. The proposed navigation

plan is based on FMS/GPS with a small backup network of enroute TACANs, VORs, and a few ILS

systems at several major airports around the country. The determination will be made at a later date

whether or not to keep the backup network in place or to get rid of all land-based radionavigation aids.

With this in mind, it is imperative we begin to familiarize ourselves with both enroute and terminal

operation of FMS and GPS systems.

B. Study Other Sources.

This section is a brief overview of FMS/GPS procedures and cannot provide by itself the knowledge

required to use GPS for enroute navigation or terminal approach procedures. It is therefore your

responsibility to study and be familiar with the appropriate manuals and regulations concerning the use

of the IEC 9002M FMS installed in the T-44 aircraft. The following sources provide additional

information: the FMS/GPS computer courseware, IEC Model 9002M FMS Operator's Manual,

NATOPS Flight Manual, AIM, and AFMAN 11-217 V2. GPS training will occur in both the

simulator and the airplane to an "introduce" level. Additional opportunities to use the GPS occur

during cross-country flights.

C. Navigation Database.

Navigation databases supporting GPS equipment certified for enroute and terminal operations contain,

as a minimum, all of the airports, VORs, VORTACs, NDBs, and all named waypoints and

intersections shown on enroute and terminal area charts, SIDs, and STARs. In the terminal area, the

database includes waypoints for SIDs and STARs as well as other flight operations from the beginning

of a departure to the enroute structure or from an enroute fix to the beginning of an approach

procedure. All named waypoints are identified with a five-letter alpha character name provided by the

National Flight Data Center (NFDC). Waypoints unnamed by the NFDC, such as a DME fix, are

assigned a five-letter alphanumeric coded name in the database (as an example, D234T - This coded

waypoint represents a point located on the 234 radial of XYZ VORTAC at 20 nm. The letter T is the

twentieth letter of the alphabet and is used to indicate a distance of 20 nm.) The navigation database in

use in the IEC 9002M FMS is the Jeppesen NavData Database.

D. GPS Approaches.

There are two types of GPS approaches: "stand-alone" and "overlay" approaches.

GPS "Stand-Alone" Approaches. GPS "stand-alone" approaches are constructed specifically for use

by GPS and do not have a traditional underlying procedure. GPS stand-alone approaches are identified

by the absence of other navaids in the approach title; for example, GPS RWY 35. Current "stand-

alone" approaches will be renamed over time as RNAV approaches so that different types of FMS

systems can be legally used to fly the approach (not just GPS-based systems); for example, RNAV

RWY 35. Straight-In Minimums on current GPS charts correspond to the LNAV Minima on RNAV

charts.

GPS "Overlay" Approaches. GPS "overlay" approaches permit pilots to use GPS avionics under IFR

to fly existing instrument approach procedures. Most overlay approaches are at civil fields and can be

identified in two ways.

GPS Not in the Title. Some approaches (typically VORs and NDBs) do not have GPS in the title, yet

they are coded into the GPS database and are retrievable; these approaches, therefore, qualify as GPS

overlay approaches. For example, if your equipment allows you to retrieve and arm an approach

named "VOR RWY 35," then the VOR RWY 35 is an overlay approach.

"Or GPS" in the Title. If the approach has the phrase "or GPS" in the title, then it is a GPS overlay

approach; for example, VOR or GPS RWY 12.

RADIO INSTRUMENTS STAGE

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