The Garmin AT (originally II Morrow, previously UPS Aviation Technologies) Apollo GX-55 is an excellent IFR enroute GPS. It is also a slide-in replacement for older Apollo Loran and Flybuddy GPS units. If you have one of these navigators, the GX-55 is the easy way to add moving map capabilities and much more. (If you have a Loran, you will obviously need to change the antenna to a top-mounted GPS antenna.)

The Apollo GX-55 is an IFR enroute (but not IFR Approach) certified GPS Receiver loaded with features, including a high-definition moving map display on a large sunlight viewable screen. The aircraft's position relative to airports, runways, VORs, NDBs, intersections, and special use airspace can be easily seen on the moving map. Operation is streamlined and pilot workload reduced through the use of Smart Keys and an intuitive interface. Airspace and navaids can be added or deleted from the map with a single press of the button.

The Apollo GX-55 features:

• Bright, clear electroluminescent display - This display measures 160 pixels wide by 80 pixels high, and its brightness is controlled automatically to match lighting conditions. This display can be set up to show a moving map, navigation information, and a graphical CDI.
• Moving map graphics - The map shows your aircraft's position relative to surrounding database items. This map may be configured to use the full screen, or only part of it. In Full-screen mode, most of the display will show the map, but the corners are used to show the TO waypoint, bearing, distance, and map scale. In Split-screen mode, the display will also show ground speed, track, and cross track error. The map may be oriented with track up, desired track up, or magnetic north up. Map objects may be selected for information or "Direct To" navigation.
• Ease of use - The GX-55 uses Smart Keys to put the most commonly used features for a given operation right in front of the pilot. The Smart Key buttons are labeled right on the display. This makes it easy to access the GX-55's power, without crowding the faceplate with buttons. Simple navigation is available right away with the "Direct To" function. There is built-in simulation software for learning the rest of the features when you are safely on the ground, and can devote your full attention to training.
• DME ARC feature. locks onto a VOR and gives you DME
• Pilot-focused design - It is clear that this GPS was designed by pilots. A full complement of E-6B calculations are available. The GX-55 can receive altitude from encoder, and it knows the minimum safe altitude and enroute safe altitude for your flight. The navigation pages are user definable and have auto sequencing. The pilot may store up to 30 flight plans of 20 legs each. Up to 2000 pilot defined waypoints may be added to the database. Automatic magnetic variation is based on your current position. The navigation computer has the ability to set up a parallel track offset. This unit also has a countdown timer.
• Peace of mind - An Emergency Search function quickly displays the 20 nearest airports (other waypoint types are available as well). Even better, the pilot may set search criteria based on runway length, surface, and lighting. With search criteria, time isn't spent deciding about airports that can't be used. The GX-55 may also perform this search around any waypoint. This is useful to know what other airports are available near your destination.
• Datacard database - The GX-55 database stores an impressive amount of information, including airports, navaids, intersections, and airspace. These database cards are front loading, which makes it much easier to keep the data up-to-date.
• Compatibility - The Apollo GX-55 may be interfaced with an HSI, CDI, autopilot, encoder, fuel sensor, and external moving maps. One RS-232 input and output is provided.