Any experienced users of Garmin GNC 300XL?

BigBadLou

BigBadLou

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Lou
If you own a GNC 300XL or have flown with it extensively in the past, I am curious about any useful feedback you might have.
Any high points, low points of the design? How is the usability? Does it feel just like the old KLN 8x or 9x series units? How about DB updates?

Thanks in advance
Lou

Edit: I posted this question specifically in this forum because I am looking to maybe have to use it for IFR.
 
It was one of the first (maybe even the first) IFR GPS certified, so it doesn't do any of the neat stuff the current units do. Very basic.

The interface is pretty much Garmin knob twiddling for entering flight plans and approaches. Only LNAV approaches of course.

If you fly an approach with a course reversal, you have to manually put the GPS in Suspend mode prior to crossing the FAF the first time, and then UnSuspend when back inbound.

If you have to hold, again you have to manually suspend, and then manually set the inbound course (and un-suspend when leaving the hold).

The display does not show holding patterns or course reversals.

There is no 'load' for approaches, they are immediately activated.

DB updates are pretty much the same as others - load the card via your computer and stick it in the unit.

If you are going to use it IFR, make sure you play with it in advance - and keep the quick reference guide handy so you can find stuff easily. The menu system is way different than anything else - only knobs, no convenience buttons.

But it works just fine. Have one in my RV-7a and have been flying with it both VFR and IFR for 8 years.
 
I have a straight 300, not the new-fangled XL version

same thing though. As mentioned it's pretty basic by modern standards but it works well and i find the interface much better than the KLN units
 
Thank you, gentlemen, for the great feedback.
If I end up buying a plane with one of these units, I will surely read the whole manual and practice on the ground and on VFR flights before going into IMC, trust me.

Thanks again.
 
One thing worth noting is that the unit is no longer supported by Garmin. Mine went Tango Uniform last July...it was still supported at that time and Garmin replaced the unit at their flat rate of $800 (or whatever it was).

Apparently I snuck in under the wire because they discontinued support a few months later. If it dies again today...I toss it into the trash.

But, the first one lasted twelve years, hopefully this one will give me good service also.

I've always liked it. It does everything I need especially since I have the equipment to shoot an ILS also.
 
The older IFR/GPS's work just fine if they dont break and you can get database updates. All the enroute you want and LNAV minimums. Combine it with an ILS and you can get in pretty low.
 
Howdy again.
I am reviving this 1-y/o thread because I have another question about the same GPS.
Now that I own an airplane with one, I want to know how to use my GNC 300XL to its maximum potential.

My question pertains to editing routes:
How can I insert a waypoint into a route?

I read the documentation (of course) and know how to append a waypoint to a route but the manual does not mention inserting a waypoint.
I grew up on Bendix-King who allows waypoint insertion so I am spoiled. So far, I have not found a way to do the same on the Garmin.

Can you experts please help?
 
If I recall correctly: Press the RTE softkey. Press the CRSR softkey. Use the small knob to enter your first waypoint. Press ENTR softkey. Continue entering waypoints until you're done.

As far as I know, there is no way to insert a waypoint like there is in more modern GPSs.
 
I had my GNC-300XL installed in 2003. I flew a lot of VFR and a lot of IFR with it. It's a great unit. I don't know how many approaches I flew with it, but it was a lot over 11 years. I yanked it in 2014 to install my Avidyne IFD-540. I sold the 300XL on ebay. I hope it found a good home.
 
I have a VFR version of the Garmin, a 250XL, and I believe you can insert waypoints into an existing route by cursoring to the waypoint where you want to insert a new waypoint. Proceed to enter your new waypoint. A new entry will be immediately inserted as soon as you begin entering the new waypoint. I have to believe the 300XL works the same way since it is nearly identical in most respects. This has been a bulletproof unit with an excellent radio and not a single problem in the 15 years I've had it.
 
I know this thread is old but the GNC XL series remains a widely-installed unit that pilots continue to encounter. I am putting together a mini-series that will help pilots better understand the GNC 300XL and its relatives (150XL, 155XL and 250XL). TheFlightPractitioner on the tube for those who are interested!
 
The 300XL has an excellent Comm radio built in. That is why mine stays in the panel.
 
I upgraded to a 530W and kept the 300xl as a back up gps/com. Mine's been in the plane since 2003 and still works just fine.
 
DGlaeser said:
It was one of the first (maybe even the first) IFR GPS certified, so it doesn't do any of the neat stuff the current units do. Very basic.

The interface is pretty much Garmin knob twiddling for entering flight plans and approaches. Only LNAV approaches of course.

If you fly an approach with a course reversal, you have to manually put the GPS in Suspend mode prior to crossing the FAF the first time, and then UnSuspend when back inbound.

If you have to hold, again you have to manually suspend, and then manually set the inbound course (and un-suspend when leaving the hold).

The display does not show holding patterns or course reversals.

There is no 'load' for approaches, they are immediately activated.

DB updates are pretty much the same as others - load the card via your computer and stick it in the unit.

If you are going to use it IFR, make sure you play with it in advance - and keep the quick reference guide handy so you can find stuff easily. The menu system is way different than anything else - only knobs, no convenience buttons.

But it works just fine. Have one in my RV-7a and have been flying with it both VFR and IFR for 8 years.
Click to expand...
I know this post is quite old, but do you recall ever having an issue with the approach not activating within 30NM? I have this unit in my 182 and it works perfectly except when flying an RNAV approach, I cannot get the approach to arm or activate. I have tried everything, looking for any and all advice that might be out there.
 
To input a fix, just click the direct to and input the identifier. If it isn’t in the database, you’ll have the option to input the GPS coordinates of the waypoint manually (you can find the coordinates on foreflight) and this will become part of the database moving forward.

From my belief, the issue with the RNAV approaches on the GNC300XL is that you have to intercept it from the start of the course or the IAF that you selected. It doesn’t work with vectors or taking a shortcut inbound like ATC normally provides, so you’ll have to request direct to the IAF and fly it inbound, and advise ATC if you need to be rerouted back to the IAF. Also on the panel I believe you’ll need to see GPS, ARM and AUTO and once you hit the IAF then ARM changed to ACTV. You can download the instruction manual for free online, it’s a pain and I get them mixed up. I think I got it to work right just a few times.

To get the approach going, click direct to and input the airport you’re heading to and click enter (you must have the airport inputed and currently routed to), click RTE and rotate knob, press CRSR until you selected the approach you want then press enter. Rotate knob again to select IAF and press enter. If your panel shows AUTO then you must fly to the IAF, you can press AUTO to switch to HOLD if you are going by vectors, and then once on the course press AUTO again. Within 2 miles of FAF the ARM will change to ACTV. Supposedly. I could never figure out the vectors.

Start at page 12:

I cannot imagine dealing with any of this (vectors different points) while flying in IMC. It’s too easy to get it confused and the whole thing needs to be reprogrammed. Fly in via the IAF seems like the easiest way.
 
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