PIREP: Garmin GNC255 Nav-Com Radio

Lance F

En-Route
Joined
Apr 9, 2005
Messages
2,946
Location
GA
Display Name

Display name:
Lance F
Did a little panel upgrade last month replacing a venerable KX-155 with Garmin's new GNC255 Nav-Com. It is a very nice unit with a lot of bells and whistles. On a cross country from Atlanta area to St. Augustine FL last weekend, I was quite happy with the reception and performance. There's an area in south Georgia where you are talking with Jacksonville Center that had been iffy for reception on the King radio that was loud and clear on the Garmin.

I did not have GS on the KX-155, so I had to change the CDI as well. The installer put in a Bendix King KI209A. Can't hurt to have a backup glideslope.

The radio includes a database with about every frequency out there. It's easily searchable for airports, navaids, ATC etc. Also can search by nearest, for example weather. With that you can find the closest airport with AWOS and check it. Nothing you can't do with a chart of course, but it's pretty easy.

The radio also allows you to monitor the standby frequency. If you have two radios, this may not be such a big deal, but for someone with only one it would be great to have. It also has built in timer.

There's also a built in intercom, which I didn't need.

Finally the display is great and will be readable in all lighting conditions.

All-in-all I'm quite happy so far with this addition to my panel.
 

Attachments

  • photo.JPG
    photo.JPG
    112.8 KB · Views: 139
Appears to have been installed upside down! Looks sharp though!
 
I think he just took the picture while at the top of a loop.
Probably right!
The old "I was inverted" explanation..

tumblr_murfxbhauW1s80ao4o1_1280.jpg
 
Did you wire it for DME or GPS or both? If both, which takes priority?
 
As far as I know, position comes from the gps.


So if using as backup navigation, what happens if gps goes out, I would do a simple test, turn off the gps, make sure it functions as expected.



Sent from my iPad using Tapatalk
 
I may have misunderstood the question. As a nav-com radio the nav part definitely tunes VORs and has nothing to do with gps. I think the nearest functions are based on GPS position. I don't think the unit has any DME capability.

Install by Precision Avionics Specialist at 6A2 Griffin, GA
 
I may have misunderstood the question. As a nav-com radio the nav part definitely tunes VORs and has nothing to do with gps. I think the nearest functions are based on GPS position. I don't think the unit has any DME capability.
The unit has it...see Pg 2-9 (section 2.5)of the pilots guide it mentions if it receives data from DME or GPS, and has note about if both GPS/DME data sources are connected that you need to press the T/F key....did you have DME antenna/capability before? If yes, then I would expect they connected DME antenna/sensor, so that if GPS is down, the DME would still work. As I said, if you had DME before, go find a VOR with DME, tune it in and turn off the GPS, I would expect that it would should display distance/speed info, but nearest function probably won't work. If you didn't have DME, this topic is mute.
In my case, I would be replacing KNS-80 that does have DME, hence my interest, since I'm looking at upgrading as well, your PIREP was very timely, thx
 
Last edited:
I did not have DME before getting this radio. Sorry I can't comment on this feature.
 
Back
Top