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GMC 307 vs. GMC 507

Dugaru

Well Known Member
Both the GMC 307 and the GMC 507 appear to be available for sale currently, and it looks like they're the same price. This prompts two questions:

1. Is there any reason anyone would still choose the 307 over the 507? From what I can tell, the 507 appears to be an upgrade and includes things like audible alerts. In other words, is there something useful that the 307 does that the 507 doesn't do?

2. Is there an upgrade path for 307 owners, short of "buy a new 507"? I would dearly love to have audible alerts of autopilot disconnect, since this has taken me by surprise on a few occasions. The flashing AP visual warning provided by the G5 is not very attention-getting.
 
I had a similar question, and this was the reply from Levi at Garmin:

“From the installers perspective, the GMC 307 primarily interfaces to the system via RS-232. The GMC 507 interfaces primarily on the CAN bus. The GMC 507 was designed to allow us to create our GFC 500 autopilot with the G5 as the primary interface. From the user's perspective, the units are very similar. If you have already purchased the GMC 307, there is really no reason to upgrade.”

Edit: I should add that Levi’s response was specifically for my G3X Touch-based system. Might be different for G5 owners.
 
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G3X and G3X Touch systems provide autopilot tones and voice alerts and a means to connect a TO/GA button, so except for the TRK button, you already have most of the features provided by the GMC 507 with a GMC 307.

If you have a G5 based system, the extra features provided by the GMC 507 are very nice.

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G3X and G3X Touch systems provide autopilot tones and voice alerts and a means to connect a TO/GA button, so except for the TRK button, you already have most of the features provided by the GMC 507 with a GMC 307.

If you have a G5 based system, the extra features provided by the GMC 507 are very nice.

3m4jEsWtAkyMYgsz8R7ncgCMFVHiXQILPjYFftF9z8UeGpbOvulTkerwN5qEENZQNBdEaRHUvPNlMifb_O-llYc2HSimxzc3T1bpe_k7vef-17VK4AT8X2Di3nmpTnpYWMn4yx93rSous4TGhcv28l5b4gJZVs0CWclCm7moj_VzsOxYzNHjCKNnhCwU_bkSbqQeRiBOsq19RP7J4wbQSyjsuuYP20pu6J2ozXKVGc43TGaaALAFUkU_UAsJ3RM9eYAQzc67mrSzF-zh3KEVLUjiQ2eH1vfRmcy1XUfNnUFh8lwZ8xB24v4twpXdJLLZN7vmk6A45s4NVcAiv-R4Y9DFfbycYahuMvVppsbZBSNarhDkgmP5qPoGEWlPUwTe1UAqLWbdo7WPi18eDAgpeqj1bmvc51BTeZQ7HKeQJ1GW7OvFBIRQ_VKfWG_GP-48KC_B2Z6Hw0N76p6PkLD4hsHM7NS_Klx295ROSqVCnKsx-Oc6GMw1pgeWmLf7_eAtbGnQ4MAs9iW-QkX6bzoqDhO9c0Bg86ZrHZmX1Yu-0Fiz1FgWHhtZAjXQZFJfGIeIA1f6KJnyWwM1e8PGnCADI7ooh3NXDtXoufH9G5TwDA3KpZqU5EIUZsBpVnvxXMiMvIeiT6dleyevyZ2GmnZdOSfe=w617-h869-no

I'm getting ready to install a 507 in my RV6A with a dual G5 setup. Am I correct in understanding that the TO/GA button option only works with the GTN series navigators not the GNS series navigators?
 
I'm getting ready to install a 507 in my RV6A with a dual G5 setup. Am I correct in understanding that the TO/GA button option only works with the GTN series navigators not the GNS series navigators?

Hello LawnDart,

Yes, that is correct.

Keep in mind, however, that the Takeoff (TO) and Go Around (GA) autopilot modes work regardless. You will just have to initiate the missed approach on the GNS in addition to pushing the TO/GA button to execute the missed approach.

With a GTN navigator, it is a single button pressure to execute the missed for both the autopilot and the navigator.

Thanks,
Steve
 
G5 based systems

If you have a G5 based system, the extra features provided by the GMC 507 are very nice.

Also my conclusion! Is there an upgrade path?

The 307's lack of an audible warning of autopilot disconnect is a major disadvantage.

Also, given that they are the same price, is there any reason that anyone in possession of all the relevant info would buy the 307 instead of the 507?
 
This thread seems to indicate that the GMC 507 is compatible with a G5 based system (no G3X).
This Web page doesn't mention the GMC 507: https://buy.garmin.com/en-US/US/p/514383#overview

Hello FORANE,

The GMC 507 can be used with a G5 only system or a G3X Touch system (with/without G5).

We are working to add GMC 507 support to the G3X system (GDU 370/375 displays).

We don't actually sell the GMC 307 anymore since the GMC 507 is the same price and does more.

Thanks,
Steve
 
Any upgrade path available for us early adopters?

A GMC 307 can be updated to a GMC 507 with a little bit of installation work. The CAN bus would need to be brought over to the GMC and the connector would need to be repinned. You would also want to add the audio wiring from the GMC to your intercom since that is your primary desire for the upgrade to the GMC 507.

Thanks,
Levi Self
 
I initially purchased the 307 for my build about 10 months ago. The day I received it from the dealer I learned that the 507 had been available for a few months. I asked the dealer if I could exchange the just received 307 for a 507.

Yes I could, but I had to pay a Garmin Co impossed restocking fee of 10% (around $100) for the exchange. I did that. What is so difficult about accepting a return for exchange, it was not a return for reimbursement of the payment?
 
I initially purchased the 307 for my build about 10 months ago. The day I received it from the dealer I learned that the 507 had been available for a few months. I asked the dealer if I could exchange the just received 307 for a 507.

Yes I could, but I had to pay a Garmin Co impossed restocking fee of 10% (around $100) for the exchange. I did that. What is so difficult about accepting a return for exchange, it was not a return for reimbursement of the payment?

Certainly a valid question especially if the 507 was available and no one told you aboiyt it .

G3expert has been an amazing resource of info for me trying to learn what?s available and what it?ll do. If I end up buying garmin it will be 100% due to his help and support.
 
Another idea

I was thinking more along the lines of a trade-in deal. The GMC 307 was superseded pretty quickly, and since the 507 is significantly better and costs the same, I'm feeling some pain as a result of being an early adopter of the GMC307/G5 autopilot combo. Any chance for an upgrade deal, or is it the classic case of a "pioneer" catching an arrow in the back? :)

BTW, I can't be sure, but it looks like the GMC 307 is still being sold. For example:

https://buy.garmin.com/en-US/US/p/531504
https://www.gulfcoastavionics.com/products/4135-gmc-307-autopilot-controller.aspx

Are you guys still selling the remaining 307s? I confess I'd feel especially frosted if I bought a 307 currently, only to learn that the 507 is available for the same price.

A GMC 307 can be updated to a GMC 507 with a little bit of installation work. The CAN bus would need to be brought over to the GMC and the connector would need to be repinned. You would also want to add the audio wiring from the GMC to your intercom since that is your primary desire for the upgrade to the GMC 507.

Thanks,
Levi Self
 
I was thinking more along the lines of a trade-in deal. The GMC 307 was superseded pretty quickly, and since the 507 is significantly better and costs the same, I'm feeling some pain as a result of being an early adopter of the GMC307/G5 autopilot combo. Any chance for an upgrade deal, or is it the classic case of a "pioneer" catching an arrow in the back? :)

BTW, I can't be sure, but it looks like the GMC 307 is still being sold. For example:

https://buy.garmin.com/en-US/US/p/531504
https://www.gulfcoastavionics.com/products/4135-gmc-307-autopilot-controller.aspx

Are you guys still selling the remaining 307s? I confess I'd feel especially frosted if I bought a 307 currently, only to learn that the 507 is available for the same price.

Dugaru,

The GMC 307 is being produced for the time being as there are some customers who want/require this unit for certification or installation reasons, but it is not in the current Garmin produced marketing materials. If you talk to any dealer about which products to buy, they should point you to a 507 for a new installation.

The GMC 307 is still fully supported and provides all of the features that were available when you purchased the product. If you feel that the additional features in the 507 are worth upgrading for, you have that option as well.

Garmin does not have a trade in program for the GMC, but you are certainly welcome to talk to your Garmin dealer about the best way to upgrade.

Please don't think that you aren't a valued customer because we continue to make newer, better products and work hard to keep costs down so that we don't have to increase the price of our newer products.

Thanks,
Levi
 
Sonalert

G3x Expert,

I noticed that on the GMC 507 to G5 Interconnect Dwg 190-02072-01 it calls for on pin 5 a Sonalert Active Low. I will not have a audio Panel GMA 245...only a GTR200B.

What is the sonalert function? Do I need it in conjunction with a G5?
 
G3x Expert,

I noticed that on the GMC 507 to G5 Interconnect Dwg 190-02072-01 it calls for on pin 5 a Sonalert Active Low. I will not have a audio Panel GMA 245...only a GTR200B.

What is the sonalert function? Do I need it in conjunction with a G5?

Hello Ed,

The ability to drive a sonalert "beeper" is only provided for aircraft with no means to receive the tone and voice alerts from the GMC 507.

Fortunately, your GTR 200B has 2 aux audio inputs, either of which may be used to receive this aural autopilot alerting output from pins 13,14 on the GMC 507.

Thanks,
Steve
 
A GMC 307 can be updated to a GMC 507 with a little bit of installation work. The CAN bus would need to be brought over to the GMC and the connector would need to be repinned. You would also want to add the audio wiring from the GMC to your intercom since that is your primary desire for the upgrade to the GMC 507.

Thanks,
Levi Self

I notice the reference to audio alerts being new with the 507. I have a 307 that I am not yet flying. Will I get basic tones or messages from the 370 (connected to audio panel) when engaging or disengaging the AP?

Larry
 
Hello Ed,

The ability to drive a sonalert "beeper" is only provided for aircraft with no means to receive the tone and voice alerts from the GMC 507.

Fortunately, your GTR 200B has 2 aux audio inputs, either of which may be used to receive this aural autopilot alerting output from pins 13,14 on the GMC 507.

Thanks,
Steve

Steve,

The GTR200B has 2 aux audio inputs........1 will go to the GDU 460 and the other to the 507. But what about if I have a second scree GDU 460 MFD? So in other words I won't need to use that second Audio in for the MFD?
 
Steve,

The GTR200B has 2 aux audio inputs........1 will go to the GDU 460 and the other to the 507. But what about if I have a second scree GDU 460 MFD? So in other words I won't need to use that second Audio in for the MFD?

Hello Ed,

Sorry, I didn't realize you had a G3X Touch system. The GMC 507 alert audio output is really just for aircraft that only have a G5 autopilot system.

There is no reason to use the alert audio or sonalert interfaces on the GMC 507 since your GDU 460 PFD provides all of the alerting audio, including autopilot, traffic, terrain, etc with a single audio connection to the GTR 200B.

There is no reason to connect the audio output from the MFD to the GTR 200B.

Thanks,
Steve
 
Garmin will know, but...

...I don't think the 307 has any audio alert capability. If you are like me, with a G5 and 307 combination (rather than a G3X), I don't think you'll get any audio related to the autopilot.

This has proven to be a problem on two occasions that I can think of, when the autopilot died in flight (the logs indicated there was some sort of network error) and I only realized it because the airplane started acting funny. The visual warning on the G5 with the 307 is a small yellow flashing square that is easy to miss.

I notice the reference to audio alerts being new with the 507. I have a 307 that I am not yet flying. Will I get basic tones or messages from the 370 (connected to audio panel) when engaging or disengaging the AP?

Larry
 
A different perspective

Levi:

I very much appreciate your response. I understand what you're trying to say, but as an early adopter of the 307/G5 combination, I can't help but look at it a bit differently. Let me explain why.

The GMC 307 is being produced for the time being as there are some customers who want/require this unit for certification or installation reasons...

I can't understand why anyone would want a 307 vs. a 507, but I'm no expert, so I'll take your word for it (seriously, not being glib there).

but it is not in the current Garmin produced marketing materials.

That's only true if you exclude your website from the category of "marketing materials." The 307 is being marketed on Garmin's website right now, and the marketing material on the website doesn't mention the 507 at all, and thus doesn't indicate that most (the vast majority?) of buyers would want the 507 instead:

https://buy.garmin.com/en-US/US/p/531504

If you talk to any dealer about which products to buy, they should point you to a 507 for a new installation.

I agree that they should be doing this, since I can't imagine an informed buyer would want a 307 -- but are they actually doing so? Has Garmin taken any steps to make sure they are doing so?

Or are the 307s in the pipeline being sold to people who probably would rather have 507s?

I fear it may be the latter. Note that online sellers--just like Garmin--don't seem to have marketing materials indicating that most buyers will want the 507. For example, here's what Aircraft Spruce's website says right now:

https://www.aircraftspruce.com/cata...MI5IeH5PDy4AIVg0OGCh0E0g3SEAQYASABEgKx9fD_BwE

Moreover, in the Q&A section, Aircraft Spruce is promoting the 307 AND the 507 for use with the G5 (rather than just the G3X), without saying anything at all about the differences between the two:

"[Q:] Which Garmin autopilot control head is needed for Garmin autopilot servos? This is a simple RV installation with only a G5. No G3 or other GPS Source. [A:] You'll need either the Garmin GMC 307 or Garmin GMC 507."

At least Spruce mentions the 507. Here's Gulf Coast Avionics. They market the 307, like Garmin, without mentioning the 507 at all, and don't even show the 507 as a related product:

https://www.gulfcoastavionics.com/products/4135-gmc-307-autopilot-controller.aspx

Here's SteinAir. Perhaps a live person at SteinAir would talk you out of buying the 307, or maybe they'd intercept a web-based order for a 307 to talk the buyer out of it. But the website sure won't give anyone a clue:

https://www.steinair.com/product/garmin-gmc-307-autopilot-control-head/

The GMC 307 is still fully supported and provides all of the features that were available when you purchased the product.

I don't disagree. But I think the change to the 507 was particularly meaningful, since I think the audio warning capability is a safety issue. I confess I didn't realize that until I got the 307 and it died twice with no audible warning. But I also suspect that Garmin, like me, realized at some point that they needed audio alerts for safety reasons (perhaps for the equivalent product in the certified market, due to FAA requirements?).

To me, a safety upgrade like this is different from other kinds of new features.

If you feel that the additional features in the 507 are worth upgrading for, you have that option as well. Garmin does not have a trade in program for the GMC, but you are certainly welcome to talk to your Garmin dealer about the best way to upgrade.

We're agreed that "upgrade" here means "buy a new 507 at full price," correct?

Please don't think that you aren't a valued customer because we continue to make newer, better products and work hard to keep costs down so that we don't have to increase the price of our newer products.

That's one way of looking at it. Here's why I don't feel like a valued customer.

From my perspective, I'm an early adopter, which is the kind of customer you ought to like. In fact, I removed a partially installed autopilot by one of your competitors, and bought yours, because I liked Garmin.

But it turns out the product I bought in the early days needed an upgrade related to safety. My experience tells me that's the case. But my only "upgrade" path is to ditch the old one and buy the new model at full price.

Meanwhile, it's very possible more people like me are being created every day. It looks like Garmin continues to sell the old 307 product in the pipeline, without taking any of the obvious steps, on its own website or with its distributors, to ensure that future customers get the 507 they almost certainly would prefer, rather than the 307.

This all looks like a customer service failure to me. What am I missing?
 
I notice the reference to audio alerts being new with the 507. I have a 307 that I am not yet flying. Will I get basic tones or messages from the 370 (connected to audio panel) when engaging or disengaging the AP?

Larry

Hello Larry,

Nothing to worry about. Your G3X system with GDU 370 provides autopilot disconnect tones, terrain, traffic, and obstacle aural alerting, 500 ft voice callouts, and much more.

A G3X or G3X Touch system ONLY uses the alert audio from the PFD.

Thanks,
Steve
 
Dugaru,

There is no conspiracy about trying to sell GMC 307 units over 507 units. In fact, Garmin prefers to sell the 507. Unfortunately, the website has lagged behind, but I do appreciate you bringing this back to my attention.

I would recommend contacting your Garmin dealer to see if they can work with you on the terms of the upgrade.

If you would like to discuss this further, please contact us directly.

Thanks,
Levi Self
 
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There is no conspiracy about trying to sell GMC 307 units over 507 units.

I did not claim, and do not think, that there is any "conspiracy about trying to sell GMC 307 units over 507 units."

I did claim--correctly--that Garmin and others were continuing to market the 307 without indicating that it had been superseded by a new product with an important new safety feature at the same price. I see that Garmin has now changed its website in that regard. That strikes me as a very positive development, and an indication that Garmin listens to its customers.

I appreciate the invitation to contact a dealer offline, but it seems to me that if Garmin is going to offer an option for 307 owners to upgrade to the 507 (other than buying a new 507 at full price....), Garmin should announce it publicly. These forums seem like a good spot for that, just like they are a great place for Garmin's other announcements.

I think most adopters of the 307/G5 autopilot combination would be interested in a reasonable upgrade path so that they can get audible alerts. I know I am.
 
I think most adopters of the 307/G5 autopilot combination would be interested in a reasonable upgrade path so that they can get audible alerts. I know I am.

Contrary to popular belief, there are tons of people out there that do not want the latest and greatest and are looking to maximize their bang for the buck. Someone would be happy to have the 307 at a slightly reduced price vs new.

I suggest to stop complaining (not like it is getting you anywhere) and offer your 307 for sale. Someone will buy it and then you can use that money to go toward a 507 with a net reduction in total cost to you.

Garmin or any other manufacturer does not owe anyone a reasonable upgrade path (which you seem to relate to cost) when new products are released.
 
Contrary to popular belief, there are tons of people out there that do not want the latest and greatest and are looking to maximize their bang for the buck. Someone would be happy to have the 307 at a slightly reduced price vs new.

I suggest to stop complaining (not like it is getting you anywhere) and offer your 307 for sale. Someone will buy it and then you can use that money to go toward a 507 with a net reduction in total cost to you.

Garmin or any other manufacturer does not owe anyone a reasonable upgrade path (which you seem to relate to cost) when new products are released.

Exactly right. This why we need a thumbs-up ?Like? button for posts...
 
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