Configuration of GTN750

[TimothyNathan 11]

I see that there are various threads relating to this question, but either I am too stupid to follow them or they are not answering my exact question.

On a "real" GTN, you can press the home button on startup and you are presented with a humungous range of configuration options.  Many of these are irrelevant to RealityXP (like which RS232 or ARINC line is physically connected to what) but some of them are really important to PBN operations, such as RF Leg activation, VNAV vs VCALC and "Transition to Approach".

Can someone tell me, in simple terms, how I get to those configurations.  If, as I suspect, I have to edit an INI file, where do I find it?

Sorry if I am being dim. 

[RXP 2,338]

Hi Timothy,

What you are referring to is most likely the 'config' mode, activated for installation in a real aircraft. There is no need for this: the functions requiring changing these in the real world are auto-magically handled by our technology in the background.

For example, you may configure the ownship icon via our settings panel, and this relates to one particular item in config mode. You may also configure TCAD interface, and this relates to a bunch of config mode options.

Do you have something specific in mind?

[TimothyNathan 11]

Yes, the ones I mentioned:

• RF Leg activation,
• VNAV vs VCALC  
• "Transition to Approach".

[TimothyNathan 11]

I have looked at the config page, and that doesn't cover what I mean.

For example, RF Procedure Legs below:

 

I use the RXP/XP-11 combination for some fairly serious research into PBN in Europe (I am one of the co-authors of the PBN Manual) and seeing how the GTN behaves in different configurations is an important part of that.

[RXP 2,338]

This is indeed configuration mode.

There is no access to these in the retail version, and I'd even say the retail version, for home/personal use, is not correctly licensed for research purposes. You might prefer an academic license instead, but this won't bring these features either for now (this is not implemented yet, but implementable nonetheless).

[TimothyNathan 11]

I am no academic! I wish.

So there is no way to see how it behaves in VNAV mode compared with VCALC mode, or with or without RF Legs?

In that case, how do you decide which options your users are going to want? 

For example, the RF legs will enable a bunch of RNP procedures (STAR and Approaches) which would not be otherwise available, but the "standard" config would have them switched off.  So do you allow people to play with, for example RNP AR APCH in the safety of their own homes, or do you say that that is not normal for a GA aircraft, in which case how do you allow people to simulate a bizjet which does have the authorisation required?

Similarly, there is a big debate taking place in the aviation community as to whether Garmin was right to disable VCALC mode when VNAV mode is enabled.  It is difficult to decide when it is not possible to swap between them.

[RXP 2,338]

The licensing option grants the right of use of the products in a certain context, along with a certain level of support and assistance. Professional licenses for example have access to more features and options, along with priority implementation of custom features. Some or all of them may later be enabled with the Home/Personal use license. Formatting might have buried the ideas, nevertheless, I was pointing at two unrelated topics in my post: licensing and features.

Having said this and speaking of features, your are raising valid points and I thank you for sharing. To better answer your questions, I'd say none of these questions surfaced yet since we've released our product, so I guess this was just not on the radar.

However, you've got me intrigued and after a quick check, like I've said above, this is not implemented yet, but implementable nonetheless.

I'll see what we can do for these specifically for a future update. In the interim, should you have a more complete list of such 'config' item worth having, and the reason why, I'd be more than willing to have a closer look. You can send me a private message and we'll further discuss offline then.

 

 

[RXP 2,338]

Hi,

Like mentioned, VNAV is an enablement by the installer. You configure a GTN either as VCALC or VNAV, and there is no in-device setting to change this. There are other such installation-only options available.

Here is a small preview of what's to come in the next update.

• Settings are grouped in their corresponding 'Config Mode' section for quick reference/lookup.
• Each is optional (the square enables, or disables - use defaults).
• Enabling VNAV also enables 'Transition To Approach', 'VDI Scale' and 'Transition Altitude'
• 'GPS Selected' is the same as 'Automatic GPS/VLOC selection' setting already present.
• Mark On Target also enables a new discrete input command: trigger the command to automatically create a MOT user waypoint at the current aircraft location.

NB: some settings might not be available in the 'retail' version, some may change until released.
We're also looking at adding equivalent settings to the GNS V2.

[TimothyNathan 11]

This is really good news, thank you.  I do hope that I am not the only person to benefit from these changes.

[StLu1000 2]

Hi

We are at least two !

I have asked RXP if he could update the GTN XPR manual with those new config options.

It is not simple to understand how to set all features and if config differ between US and Europe?

Is GTN 750 comming with some standard settings in real aircraft for europe? Is there any best practise?

That would be nice.

BR

Stefan

[TimothyNathan 11]

On these three configurations, I would expect VNAV and Transition to Approach to be switched on and RF Legs switched off, as it is a certification issue.

RF legs are a hot topic in Europe, as EASA has set some high certification standards (such as requiring EHSI, moving map in the pilot’s field of view and (I think) autopilot) which the PPL/IR community is saying are quite unnecessary.  

Thanks to RXP, I have done some experiments on limiting cases (very strong winds which the arc passes through, with OEI) and found that they remain flyable with a mechanical HSI.  These results are being fed back into EASA to demonstrate that the requirements are over engineered.

[RXP 2,338]

Hi,

Detailed RF leg flying experimentation can be found here:

https://onedrive.live.com/?authkey=!ADzuQK6cj9mG4Ew&cid=110AA5B593D58477&id=110AA5B593D58477!6339&parId=110AA5B593D58477!6338&o=OneUp

Garmin seems to conclude the same.

[TimothyNathan 11]

Yes, though the target was somewhat different (no A/P, FD, rather than no EHSI, or even HSI) and they didn't do it in really gruelling conditions, as I described.

One interesting conclusion I came to was that it is easier on an OBS than a mechanical HSI, but the HSI trumps the OBS in so many other modes of flight that it would be ridiculous to replace it solely for RF legs.