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The GNC 420 adds a TSO-certified 760-channel comm transceiver to the GPS 400’s color display. GNC 420 has all of the IFR GPS and comm features of the GNS 430 minus the VOR, ILS or glideslope capability you may already have in your aircraft. GNC 420 is available with optional WAAS navigational capabilities.

Save Space with Built-in Comm

The reliable GNC 420 delivers clear communication from its 10-watt, 760-channel VHF transceiver. In the alternative, GNC 420A features a high power 16-watt transmitter for high altitude turbine aircraft. With the 420's frequency nomination feature, you can easily load your next com frequency into standby with the touch of a button.

Get High-Resolution Mapping

GNC 420's 4-inch high-contrast display with brilliant colors makes it easy to read and interpret pilot-critical information. Effective use of color makes it easy to see your position relative to ground features, chart data, navaids, flight plan routings, approach procedures and more. Conveniently scan information from wide viewing angles, even in direct sunlight.

Enhance Situational Awareness

GNC 420 seamlessly integrates built-in terrain and navigation databases, providing a clear, concise picture of where you are and where you’re heading. The 420's huge Jeppesen® database, updated with front-loading data cards, contains location reference for all airports, VORs, NDBs, Intersections, Flight Service Stations, published approaches, SIDs/STARs, Special Use Airspace and geopolitical boundaries. A detailed basemap clearly shows airports, cities, highways, railroads, rivers, lakes, coastlines and more. Using information from the built-in terrain and U.S. obstacles databases, the 420 displays color coding to graphically alert you when proximity conflicts loom ahead.

Expand Your Panel Mount

GNC 420 is easy to interface with a wide array of optional sensors and tracking systems, allowing you to see and avoid hazards such as threatening weather, lightning or air traffic. With an optional subscription to XM WX Satellite Weather™ and the addition of the GDL69 or GDL69A datalink receiver, you’ll have access to up-to-the-minute, high resolution weather for the U.S., right in the cockpit. Information includes NEXRAD and METARs and can be laid directly over Jeppesen and topographic map databases. With an additional monthly service fee, GDL 69A delivers XM Satellite Radio to your aircraft. Add the Garmin GTX 330 Mode S transponder, and GNC 420 will also display Traffic Information Services (TIS) alerts that identify surrounding air traffic.

GNC 420: Big-picture situational awareness

  • Pilot-defined course selection and waypoint hold
  • Closest point of approach
  • Departure and arrival frequencies
  • Approach navigation using published approach procedures stored on NavData card
  • Terminal navigation using DPs/STARs from NavData card
  • True airspeed
  • Density altitude
  • Winds aloft
  • RAIM availability
  • Sunrise/sunset times
  • Trip and fuel planning
  • Vertical navigation (VNAV)

Physical & Performance:

Unit dimensions, WxHxD: 6.25"W x 2.65"H x 11.0"D (15.9 x 6.7 x 27.9 cm)
Display size, WxH: 3.3"W x 1.8"H (8.4 x 4.6 cm)
Display resolution, WxH: 240 x 128 pixels
Display type: 8 color DSTN LCD
Weight: 5.8 lbs (2.6 kg)
Voltage range: 14-28
Built-in VHF Comm: yes, 8.33/25 kHz channel spacing
Transmit power: 10 watts minimum; 16 watts minimum (GNC 420A)
Built-in VOR/Loc/Glideslope: no
SBAS/WAAS receiver: 12 channel
IFR or VFR: IFR


Maps, Databases & Memory:

Basemap: yes
Navigation data: full and non-precision approaches, DPs and STARs
Navigation database coverage areas: Americas, International or Worldwide
Preloaded Terrain database: yes
Preloaded Obstacle database: yes
Preloaded SafeTaxi™ airport diagrams: no
Preloaded Garmin FliteCharts®: no
Jeppesen ChartView™: no
Waypoints/favorites/locations: 1,000
Flight plans: 20 reversible; up to 31 waypoints each


Features & Benefits:

Fly SBAS/WAAS approaches: no
Front-loading datacards (conveniently update database information): yes
XM WX Weather & Radio for U.S. & Canada compatible: yes
Traffic Information Services (TIS) alerts compatible: yes
Class B TAWS alerting compatible: no

  • GNC 420 Legacy (10 watt) receiver
  • Basemap: Worldwide Land
  • Jeppesen datacard
  • TAW/Terrain datacard
  • TSO GPS antenna
  • Installation kit

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Prop 65 Warning: This product may contain chemicals known to the State of California to cause cancer, and birth defects or other reproductive harm.