This document is the user guide for GARMIN GNC 300XL
The Pilot’s Guide and Reference is the primary user manual for the Garmin GNC 300XL panel‑mount IFR GPS. It explains how to install, power, and operate the unit, and includes safety warnings, warranty details, and a complete list of accessories.
The guide is organized into sections covering navigation, communication, waypoint and database handling, route planning, approach procedures, unit settings, specifications, troubleshooting, and an index. Appendices provide detailed hardware specifications, installation tips, simulator mode information, and message/abbreviation tables.
| Physical size | 6.25"W x 5.8"D x 2"H (159mm x 147mm x 51mm) |
|---|---|
| Weight | 39 ounces (1.11 kg) |
| Power input | 10‑15 V DC with power cable (aircraft power) |
| Operating temperature | -67 °F to 185 °F (‑55 °C to 85 °C) |
| Position accuracy | 15 m (49 ft) RMS |
| Update rate | 1 per second, continuously |
The GNC 300XL will not automatically sequence to the missed‑approach holding point; the pilot must activate a direct‑to after crossing the MAP to begin the missed‑approach.
After crossing the MAP, press D then E; the unit will provide direct navigation to the holding point.
The unit reverts to battery power and continues navigation after any key press.