Garmin 250XL to Garmin 300XL

Gmonnig

Pre-takeoff checklist
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Nov 12, 2015
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Lees Summit, MO
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Grant
I know most people will say putting an older GPS into the plane isn't worth the trouble but I have a question. I am looking to make my plane a /G instead of the current /A. My partner in the plane isn't IFR yet (might be a year or two) and we've talked about putting the Avidyne IFD440 in. Money is the issue right now since we just installed a McCauley prop on our Comanche last month. He seems to think getting his IFR isn't a priority until we get the 440 put in or something? I on the other hand would just like to file as a /G ASAP. I actually love flying VOR to VOR but the need for GPS approaches are becoming important. Is the Garmin 300XL a direct pin for pin replacement with the VFR Garmin 250XL (currently in the plane)? Most are probably going to steer me towards a 430W but that would involve more install $$. I do have center Stack radios so would I need the annunciator panel to make it IFR, even if it would have it's own dedicated CDI?
 
Also, keep in mind that just swapping in the 300XL won't make you /g legal. You have to seek a field approval from the local FSDO, which is a bit involved (though not insurmountable). I recently went through the field approval process with the KC FSDO for an IFR GPS, happy to offer insights (PM me if you like). You're going to struggle to get an avionics shop to help you with this, too. Best to find an local A&P/IA willing to do an "owner-assist" kind of deal.
 
Can you even get a current database for a 300XL?
 
I wanted to do the same thing (also have 250XL) but got constant discouragement from my avionics shop who said they would do it but its not a good idea. They seem to think I need WAAS approaches (I don't) and the unit is "unsupported". I called Garmin and they said they would fix it if it broke EXCEPT for the display which I guess they don't stock anymore. I think an IFR install needs a CDI indicator so you may need to factor that in with the annunciator panel. I still think it would be right-sized for me but install estimates range from $3K to $5K plus the 300XL/annunciator/indicator config - figure $3500. Add $3-4K and you probably can get a 430W so it is never easy.
 
I wanted to do the same thing (also have 250XL) but got constant discouragement from my avionics shop who said they would do it but its not a good idea. They seem to think I need WAAS approaches (I don't) and the unit is "unsupported". I called Garmin and they said they would fix it if it broke EXCEPT for the display which I guess they don't stock anymore. I think an IFR install needs a CDI indicator so you may need to factor that in with the annunciator panel. I still think it would be right-sized for me but install estimates range from $3K to $5K plus the 300XL/annunciator/indicator config - figure $3500. Add $3-4K and you probably can get a 430W so it is never easy.

Shops just don't want to do the field approval dance, period. I've been trying to get a shop to help with a field approval for a Garmin G5 and ZERO are interested in helping (it's not worth the headache I guess). Self-install of one of these older GPS units isn't bad at all (and IMHO it's the only way to make it economical), you just need to have some mechanical/electrical ability, ability to read an installation manual and a willing A&P/IA to help with the paperwork. If you're paying a shop to do the work, I don't think it makes sense, go with a 430W or better.
 
Shops just don't want to do the field approval dance, period. I've been trying to get a shop to help with a field approval for a Garmin G5 and ZERO are interested in helping (it's not worth the headache I guess). Self-install of one of these older GPS units isn't bad at all (and IMHO it's the only way to make it economical), you just need to have some mechanical/electrical ability, ability to read an installation manual and a willing A&P/IA to help with the paperwork. If you're paying a shop to do the work, I don't think it makes sense, go with a 430W or better.

Having installed many elaborate (for their day) car stereos in the 19070's and very early 1980's, this seems pretty straight forward. But who would have to sign off to make it IFR legal?
 
Having installed many elaborate (for their day) car stereos in the 19070's and very early 1980's, this seems pretty straight forward. But who would have to sign off to make it IFR legal?

You need an A&P/IA to "supervise" the work, make the logbook entries (for the "VFR Only" installation), and prepare the AFMS and 337 to go to the FSDO (or whatever it's called now) for a field approval, which grants the IFR approval. IMHO, you're much better off preparing all of the paperwork yourself, after reviewing the relevant Advisory Circulars, and giving your A&P/IA a package to sign and submit to his PMI. In my experience, A&Ps are horrible with paperwork (don't like it and are bad at it). The FAA loves paperwork, so if you can personally ensure the papers are in good order, it's going to make for an easier process with the FAA.
 
I just pulled out a GNC300XL and MD41-444 out of my Comanche. Used it for 15 years. Display is good. only blemish is the frequency swap button, the 2 sided arrow is not visible anymore.
I reused the 106A CDI in the GTN650 install so I don't have that. text me at 580 Five Nine Five 0349. I'll text back pictures and you can make a reasonable offer.
 
We just went through the same debate. We even bought a very nice used 300xl and annunciator and to make everything legal. Our avionics shop dissuaded us though due to the fsdo approval costs. We decided to go all in and are putting in a 440. If you decide to go the 300 route let me know and I'll make you a great deal on the garmin and annunciator


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Thanks for all the info! It's crazy how complicated this crap can get. I could probably install a 300xl in little to no time. Sh*t, I did all the wiring on my custom mahogany boat which is certainly more complicated than my Comanche. My A&P is awesome and would certainly help but I'm not too sure how nice the KC FISDO would play. I guess I'll just stick with the /A until I can scrounge up another $15,000. Or maybe buy an experimental
 
Reviving an older thread but looking for a Garmin 250 XL NavData card and database … or a Garmin300 XL that a member would like to sell. Reason: purchased a vintage TriPacer with a Garmin 250 XL missing a NavData card and would like the GPS for the XC trip home.
 
David, hopefully you found your answer by now, but I did the same thing for the same unit about 9 months ago. They are still available—you need the right SD card and a Skybound adapter to update the database through your PC. It’s going to cost about $275 I believe, and it’s through shop.jeppesen.com. I forget the details but wanted to shoot a quick note, but if you need more help you can message me and I’ll refresh my memory. John
 
David, hopefully you found your answer by now, but I did the same thing for the same unit about 9 months ago. They are still available—you need the right SD card and a Skybound adapter to update the database through your PC. It’s going to cost about $275 I believe, and it’s through shop.jeppesen.com. I forget the details but wanted to shoot a quick note, but if you need more help you can message me and I’ll refresh my memory. John
Hi Chow_Chow, good info on the Jepp card and yes I did find the card from them and a card reader via local PoA member so I’m all set.
Waypoints showed but flew 6,000 miles in 3 months without a satellite signal. Used a iPad/ForeFlight and portable ADSB device for navigation. Radio function works fine though.
Recently discovered the antenna cable was cut and re-taped near antenna!
I tried resplicing and reattaching a new connector a few weeks ago but didn’t solve the problem.
Finally got the GPS satellite function to work last weekend w/a new antenna cable and a new antenna.
Psyched to try it out in flight tomorrow.
David
 

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Good catch on the antenna. Hope the flight test goes well! It’s a pretty nice capability to have. I also like seeing class b/c airspace on the nav page to make sure I don’t stray anywhere. I needed my nav card update for that last year because it was about 20 years old and quite a few changes since then. John
 
As I’ve noted in past threads, I used to have a 300XL and it did very well. I had it connected to a 396 then an Aera 660, both mounted in the panel with an Airgizmo. That gave me color moving map with the flight plan from the 300XL fed to the handheld. Adding a GDL50 gives me ADS-B weather and traffic plus an AHARS-driven backup AI (I migrated to a GNC355 but still have that connected to the Aera).

The only reason I switched from the 300XL to the 355 was the fear of the 15-year-old 300XL dying someday and not being fixable, plus the fear Jeppesen would stop the database support. It was a good excuse to spend money, basically…
 
I am debating between sliding in a 300XL and updating the annunciators or going to the 355 for all the reasons you described. I got quoted around $11,500. I would go for it other than I wonder if it is worth it for my 1968 Cherokee which otherwise needs paint and has a high time engine. I’m still on the fence.
 
I am debating between sliding in a 300XL and updating the annunciators or going to the 355 for all the reasons you described. I got quoted around $11,500. I would go for it other than I wonder if it is worth it for my 1968 Cherokee which otherwise needs paint and has a high time engine. I’m still on the fence.
Looks like I can’t PM you with how your profile is set. I have the annunciators, indicator, and even a DAC GPSS that was pulled from when I had the 355 installed if you’re interested in those.
 
Excellent, thanks, I’ll reach out if I decide to try to go that way (and see if I can fix my profile to accept PMs). I likely won’t really decide anything before finishing the annual at the end of September, though. Thanks very much.
 
Well the revived Garmin 250XL worked like a champ today on a round trip flight from KFDK home base to KSHD Shenandoah Valley Airport to help my daughter get settled into college at James Madison Univ. Good situational awareness with the panel mounted unit and an iPad for additional details. I can see how a Garmin 300XL with annunciator and CDI/HSI would help too.
 
I would be interested in buying DGlaesers 300XL to replace my 250XL in my 48 Luscombe 11A and enunciator. Phnine182698two70.
Raylon
 
I only have the 300XL. The annunciator was sold a while back and I use my EFIS as the CDI.
Let me know if you are still interested. Send a PM or contact me at glaeserx1 at gmail.
 
Is there any difference between the 250XL Navdata and the 300XL Navdata. I entered both into my Jep account for the same airplane and they only gave me one download.
 
Is there any difference between the 250XL Navdata and the 300XL Navdata. I entered both into my Jep account for the same airplane and they only gave me one download.
I’m not sure about all the differences in Navdata for the Garmin 250XL vs 300XL but the 300XL is an IFR unit so presumably the data includes IFR fixes and maybe non precision approaches, etc. I upgraded my 250XL Jeppeson database to the IFR 300XL version.
 
I believe same database, just the 250XL omits approach/STAR submenus within the RTE button functionality, which in the 300XL are of course available for approach/SID/STAR selection. But I could be wrong, last time I flew behind a 300XL was my CFI-A checkride in a rental 172RG in 2005.
 
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