Important Notes:
These products have truly reinvented the stand-alone aviation COM radio with novel features like reverse database look-up and the COM monitor function, which bring new efficiencies to cockpit radio management. Beyond that, these products demonstrate Garmin’s commitment to aviators worldwide, providing the solutions they need to meet the latest regulatory requirements in their regions, such as the recent SES mandate. The SES mandate The SES mandate aims to enhance safety and efficiency of air transport in Europe by tripling the number of channels available for aircraft communications. This mandate requires all European aircraft using European airspace to be equipped with 8.33 kHz radios by December 31, 2017. Select GTR and GNC models offer both 25 kHz and the 8.33 kHz operational capabilities required to comply with the law. The GNC series NAV/COM The GNC series NAV/COM radios offer all of the same COM features, while also adding navigation capability with VOR/ILS with Glideslope. The GNC series works well with select Garmin flight displays including the G500, G600, G500H and G3X to display the NAV indicators in the primary field of view, and can integrate with most autopilots. The GTR and GNC series are more powerful than their SL-series predecessors with versions available with 10- or 16-watt transmit power. The GTR 225 includes 10 watts of transmit power and 25 kHz frequency spacing. All products in the series have received the Federal Aviation Administration’s (FAA) Technical Standard Order (TSO) authorization. Night Vision Model Night Vision Goggle (NVG) capable COM and NAV radios. The GNC NAV/COM and GTR COM series of radios are now even better with the addition of new, NVG capable versions. This latest edition grows our list of NVG capable products which already includes NVG specific GTN series navigators as well as G500/G600/G500H flight displays. |
![]() |
WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov. |
I had to repair or replace and I’m glad I replaced an old Narco with this, the features this little box has is amazing. Hard to believe what all it can do and it’s just a nav comm
GARMIN GNC 255A NAV COM 10W 8.33 KHZ TSO
We have had this installed (GNC 255 A) paired with a KI-204 indicator and PS Engineering PMA 8000-BT audio panel utilizing the Approach FastStack connecting system (which allows an A&P to install (as long as an IA signs off on the paperwork) on our 1958 Cessna-172.. It is by far the best navcom we’ve had in this airplane, crisp,clear,long range, easy to learn the basics and most of the features. Everyone who flies with us compliments us on the combination (especially if they make or receive a phone call through the PMA 8000-BT), or when they make some ILS approaches, use the comm over long distances (100 miles or sometimes longer). The GNC 255A was a purchase we would purchase again without any hesitation whatsoever.
This unit (GNC255B) was installed with a Dynon HDX and a GPS175, the installation was relatively easy and Dynon had instructions for the interface wiring for both units, (although you will need to hunt Dynon paperwork for those instructions. . . the set up procedure was good. . . if you are computer savvy
Please note, Aircraft Spruce's personnel are not certified aircraft mechanics and can only provide general support and ideas, which should not be relied upon or implemented in lieu of consulting an A&P or other qualified technician. Aircraft Spruce assumes no responsibility or liability for any issue or problem which may arise from any repair, modification or other work done from this knowledge base. Any product eligibility information provided here is based on general application guides and we recommend always referring to your specific aircraft parts manual, the parts manufacturer or consulting with a qualified mechanic.
For a new glideslope and LOC/VOR CDI receiver the GI 106A is the first recommendation under part number 11-05768.
Yes, the database is an optional feature on the GTR & GNC series.
Yes, the GNC series will still output the NAV like the older SL 30 units.
Yes the Garmin GNC Nav/Com has a 429 Arinc output which can go to the Sandel.
For the Com side 5A @ 28V & 10A 14V and for the Nav side 2A @ 28V & 4A @ 14V. The amp draw varies based on the Com and Nav as well as 14 and 24 volt systems. Always refer to the manual before installation.
There is no recommended antenna for any radio as almost any Com and Nav antenna can be used. They are built for different speed ratings, mounting locations and some are certified (TSO'd) and some are for experimental aircraft only. Type antennas in the search box on Aircraft Spruce website for our product selection. Archer and Advanced composite are two wing tip types but both are not certified (TSO'd) as they are intended for experimental aircraft only.
No, it is a basic intercom, for a stereo option or 3.5mm input you will need to go with an external intercom.
It can operate on a 14 or 28 volt system.
It is possible but we will have to special order this for you and may not cost or have the same lead-time as Garmin does not stock it this way. Please call us and we can get pricing and lead-times.
In speaking with Garmin, the GNC 255 does not have the standby VOR like the SL 30.