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GTN 650 Warnings after Update to v6.50

PAFlier

I'm New Here
I'm starting a new thread, since I think others might be having issues with the GTN SW updates.

I posted this one to an older thread, but didn't get any replies. Sorry for the repeat. But this probably warrants a new thread. I saw some other discussions on this in other threads. But no direct answers to my specific issues.

I have a GTX 345 connected to a GTN 650. No other avionics are connected. So, I don't have a heading source, or an altitude source connected to the GTN650.

I have a Gillham Altitude source connected to the GTX. Both units have the latest software.

GTN v6.50
GTX v2.12

I'm having a little trouble with the configuration.

The GTN gives me two warning messages (that I can't clear)

1) NAV ANGLE: NAV Angles are referenced to True North

2) VNAV: Unavailable: Barometric altitude lost.

I have Altitude Source and Heading Source disabled on the GTN.

Any suggestions would be helpful.

Questions:
1) How do I get rid of the warning messages?

Also, it seems that I might want a pressure altitude going to the GTN for VNAV support:

2) Can the GTX send the pressure altitude source to the GTN?
3) - OR- Do I need to connect a pressure altitude source to the GTN to get VNAV support?
4) If I connect the Pressure Altitude to the GTN, do I need it also connected to the GTX,
5) or can the GTN feed the GTX the pressure altitude source?
 
Don’t know about #1 but for #2, if VNAV is enabled in the configuration setup and the GTN does not have its required inputs, it will throw an error. To get rid of the error, disable VNAV or give it what it wants.

Suggest you contact [email protected] and they will help you get it sorted.
 
Config problem

Hi,

You need to obtain the latest version of the GTN install manual (ver 14) and read the configuration section. As you have no magnetometer you'll get the true north reference. With regard to the VNAV msg, you have no airdata source providing barometric corrected altitude (like a G5). This can be fixed by changing the the VNAV setting in the GTN to VCALC. Without a airdata source you can't use the new VNAV function as I understand it. Call Garmin or talk to your aviionics guy.
 
I have a magnetometer and two G5's and I get the same message #2 on my GTN650 also. I am lost! My 650 won't fly approaches when directed to my Trio Pro pilot but Ifly 740 takes me to the airport just fine. All these boxes and updates, I wish they would play together quietly.
 
I'm starting a new thread, since I think others might be having issues with the GTN SW updates.

I posted this one to an older thread, but didn't get any replies. Sorry for the repeat. But this probably warrants a new thread. I saw some other discussions on this in other threads. But no direct answers to my specific issues.

I have a GTX 345 connected to a GTN 650. No other avionics are connected. So, I don't have a heading source, or an altitude source connected to the GTN650.

I have a Gillham Altitude source connected to the GTX. Both units have the latest software.

GTN v6.50
GTX v2.12

I'm having a little trouble with the configuration.

The GTN gives me two warning messages (that I can't clear)

1) NAV ANGLE: NAV Angles are referenced to True North

2) VNAV: Unavailable: Barometric altitude lost.

I have Altitude Source and Heading Source disabled on the GTN.

Any suggestions would be helpful.

Questions:
1) How do I get rid of the warning messages?

Also, it seems that I might want a pressure altitude going to the GTN for VNAV support:

2) Can the GTX send the pressure altitude source to the GTN?
3) - OR- Do I need to connect a pressure altitude source to the GTN to get VNAV support?
4) If I connect the Pressure Altitude to the GTN, do I need it also connected to the GTX,
5) or can the GTN feed the GTX the pressure altitude source?

Hello PAFlier,

The GTN Pilot Guide explains the meaning of the "NAV ANGLE - NAV Angles are referenced to True North (T)." message. The pilot guide also explains how to change the nav angle units to be Magnetic, True, or User. Most of us want nav angles to be Magnetic, but yours is set to True, or there is a database problem that prevents mag var from being determined.

The GTN Pilot Guide also explains the meaning of the "VNAV - Unavailable. Barometric altitude lost." message. A baro altitude source is required to use VNAV. Pressure altitude is not an acceptable alternative to baro altitude to use baro VNAV. You will need to change your setting to VCALC if no such source is available in your aircraft.

Thanks,
Steve
 
I have a magnetometer and two G5's and I get the same message #2 on my GTN650 also. I am lost! My 650 won't fly approaches when directed to my Trio Pro pilot but Ifly 740 takes me to the airport just fine. All these boxes and updates, I wish they would play together quietly.

Hello swordtail,

Do you have your G5/GTN system wired and configured per the guidance on page 7-10 of the rev. 3 G5 Installation Manual?

There is no mention if a GAD 29 is installed, but the G5 system provides barometric altitude to the GTN over A429 from the GAD 29 as shown in the image below.

To enable GTN provided VNAV guidance on the G5, you will need to change the GPS A429 output (Out 1A/1B) on the GTN from "GAMA Format 1" to "Garmin 429". This will be mentioned in the next G5 manual update.

Sorry, but we probably can't provide much help with the 3rd party autopilot. Everything would be nicely integrated if the system included GSA 28 servos connected to the G5 units.

RsCDvJi1rh-zvJPaBj4GIMyUwG25SnkzHB8nO1PTmkwI7XD6znCYEqsULg42y2yl80lwxF724yiVTeifir8_1IPFrb2vjLPRQODRNEyBoUSjyu0LD7D4lWx_oY4NE6FAYadd27NB4tJZqjcFNrxcuKAMYBXBxK12DU2Y9AEpL65Pbl6syYBRMuO57Gia_u6Q9iUXDV_MKPmfBMGPGrR0uYBlJTszjRcr0VENWH1OHYjHo6jl52yU4dxt9TiaroUkwgZTv-IdeyDt6dB6BX9Sl-GMvQlHXdc60yOPY4oJimkQBMNfyxoOJa4nLTqrJZdW01nj3IdvOReY8SLuCZSONXFBKVFajYE-efcyN5XX6o-ZjsHAGq0l1vaS39YHV7KmqSA_2k1UrkjyTdATYDkURIlVS5vGH64WoMDeZJU0mYHU6W3i472LkvO4vgHI4If6O8lPXVNH78cRR_NEeaW7YtLrA5Qeq-5UxAKdPnLCtgO-GuLmqLhNHsiMXXM-GxSPG9vLiYnTb5_luFaqBRXxPhkFmTO5SajdPX_kANL35c9Tn9WwjOrcHeNue25fKmfj9cgEIQDnh2LVKK8uJo3NjUOVOi3WRuYnWqXVSGB6bbYNKDhOEQDzOB9KbTZXsWs=w375-h740-no


Thanks,
Steve
 
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Trio not authorized for coupled approaches

I think the title says it all. The Trio is specifically not authorized for coupled approaches or operation below 500 ft AGL.
 
Hello PAFlier,

The GTN Pilot Guide explains the meaning of the "NAV ANGLE - NAV Angles are referenced to True North (T)." message. The pilot guide also explains how to change the nav angle units to be Magnetic, True, or User. Most of us want nav angles to be Magnetic, but yours is set to True, or there is a database problem that prevents mag var from being determined.

The GTN Pilot Guide also explains the meaning of the "VNAV - Unavailable. Barometric altitude lost." message. A baro altitude source is required to use VNAV. Pressure altitude is not an acceptable alternative to baro altitude to use baro VNAV. You will need to change your setting to VCALC if no such source is available in your aircraft.

Thanks,
Steve


Hi Steve,

I verified the VCALC clears the VNAV warning (Thanks to TCB also).

I downloaded the latest Pilot Guides from support.garmin.com. thanks for the hint! :) I don't have access to the latest GTN650 installation manual. My GTN was installed in 2012.

The GTN RS-232 configuration for the GTX mode S+ also gives an option to send altitude data to the GTX. Do you know what altitude source is sent? Does this only apply if I have an Altitude source connected? I'm curious what the GTX would do with the data. Is it a potential replacement for the GTX pressure altitude source?

Richard
 
I think the title says it all. The Trio is specifically not authorized for coupled approaches or operation below 500 ft AGL.

Please provide a reference for this statement. Who specifically has said ?not authorized? with respect to coupled approaches in an EAB aircraft? Mine flies the airplane right down to the runway, just fine.
 
I have a magnetometer and two G5's and I get the same message #2 on my GTN650 also. I am lost! My 650 won't fly approaches when directed to my Trio Pro pilot but Ifly 740 takes me to the airport just fine. All these boxes and updates, I wish they would play together quietly.

I think your problem may be related to the format change in the new software. Your Trio may be unable to read the new arinc format (Garmin 429). I too wish everyone would play quietly together, but that?s not the real world. In the real world, if you are the sole source of TSO?d GPS below $10K, you use that to your advantage to try to force competitors out of business.
 
Check Trio Site

In the AFM for the Trio (which required FAAApproval) it states not approved for coupled approaches or operation below 500 ft AGL.
 
Mis-information

In the AFM for the Trio (which required FAAApproval) it states not approved for coupled approaches or operation below 500 ft AGL.

You’re looking in the wrong place. The sub-section on the Trio web site dealing with installation in normally certified aircraft via STC but no TSO has these limitations. The Trio sold for EAB aircraft has no such limitations, nor is there any ‘faa approved afm’.
 
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Sorry, but in my book when in IMC using a piece of equipment not approved/certified and with a specific exclusion of use in IMC, even if it can be interpreted as only for a certified aircraft, it should not be used for the excluded function even in an EAB. Doesn't matter if the exclusion is for only certified airframes. I'm the guy that is not risk averse with regards to minimum ceiling/visibility approaches, but I am risk averse with my navigation equipment capabilities. When the piece of avionics equipment is not authorized for certain functions in a cetertified aircraft why would it be safe to rely on those functions in an EAB? Notice there is not an Approach mode in the Trio? Your risk profile may be totally different from mine.
 
Sorry, but in my book when in IMC using a piece of equipment not approved/certified and with a specific exclusion of use in IMC, even if it can be interpreted as only for a certified aircraft, it should not be used for the excluded function even in an EAB. Doesn't matter if the exclusion is for only certified airframes. I'm the guy that is not risk averse with regards to minimum ceiling/visibility approaches, but I am risk averse with my navigation equipment capabilities. When the piece of avionics equipment is not authorized for certain functions in a cetertified aircraft why would it be safe to rely on those functions in an EAB? Notice there is not an Approach mode in the Trio? Your risk profile may be totally different from mine.

Since I see by your low post count, forgive me if I assume you’re not up to date on EAB instruments and history. For years the FAA would absolutely not approve any non-TSO’d device in a normally certified aircraft. Now, they’re cautiously taking baby steps. Some non-TSO EFIS units may now be used - but only for the AI function, nothing else. Similarly they have limited the use of non-TSO’d autopilots. For the last (what? Ten years?) the majority of EAB aircraft built for ifr have non-TSO’d flight instruments, non-TSO’d CDI’s, non-TSO’d autopilots. Now non-TSO’d GPS’s are appearing in ADSB-out boxes. There is no evidence that these devices are less safe than TSO’d devices, which is exactly why the faa is now allowing them in normally certified aircraft. In fact, compared to flying behind a vacuum driven AI/DG, I consider my non-TSO’d flight instruments to be an improvement. As to the Trio, it is perfectly capable of flying GPS LPV approaches. Connected to an EFIS, it will fly ILS approaches as well.
Edit: I see I forgot to address your comment about ‘approach mode’. In the old days, even TSO’d autopilots weren’t that good, and you had to choose between ‘enroute mode’ (where the autopilot would allow significant cdi deviations but smoothly correct them) or ‘approach mode’ (where deviations were promptly corrected, but with more frequent turning and banking). Modern autopilots are so good that this distinction is lost.
 
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Your forgiven, as I've only been flying for 42 years, instrument rated for 36 years, worked on navaids and avionics as well as other electronic items in the military, currently fly with dual G5s, GTN 650, GTX 345 and dual KX 155s w/GS for backup. Recently joined here to decide if I wanted to build an RV in the shed out back. As an EAA lifetime member, I'm very familiar with TSO/non-TSOed equipment, the ability of a EAB plane to use a multitude of non approved the EAA effort to obtain STCs for non certified items for use in certified airframes and the NORSEE efforts. Still it's my approach that I would not use a safety of flight item that had a specific functional exclusion for a certified aircraft in the STC for that function in an EAB. Now that's my opinion, and I'm aware that yours is different. This thread is supposed to be about GTN 650 issues.
 
I think your problem may be related to the format change in the new software. Your Trio may be unable to read the new arinc format (Garmin 429). I too wish everyone would play quietly together, but that?s not the real world. In the real world, if you are the sole source of TSO?d GPS below $10K, you use that to your advantage to try to force competitors out of business.

We know the nice folks at Trio pretty well, and we certainly didn't create new GTN software in an attempt to put them out of business.

Some facts:
  1. Garmin developed a new GTN VNAV feature that many customers have requested, and gives it away to all new and existing GTN owners.
  2. The new GTN software is on our website so EAB owners can install it themselves and avoid any potential labor fee from dealers to install the free software.
  3. The new GTN software keeps the old ?GAMA Format 1? ARINC 429 format when the new VNAV capable ?Garmin 429? format was added to make sure and retain compatibility with existing equipment.
  4. While the new "Garmin 429" format contains some additional labels that support VNAV, all of the old "GAMA Format 1" labels are still present, so if an existing device ignores labels that it doesn't need, it should be fine using either "GAMA Format 1" or "Garmin 429" format.
We welcome swordtail or PAFlier to contact us directly by phone or email shown below if we can help in any way.

Thanks,
Steve
 
Thanks for all the help. My problem is related to the magnetometer. I called and talked with a tech at Garmin.
 
VNAV Unavailable msg

I recently installed GTN 650 ver 6.51 and now I too am getting the "VNav Unavailable" msg. Might someone be willing to share how to go about specifying 'VCALC'?

Thanks in advance..
 
I have the same problem here - I just called Garmin and they refuse to tell me. It's just one setting. Anyone able to advise?
 
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