There are other posts about the merits of the MSFS RNAV implementation, but here is a new (for me) observation which may just help WT in fixing this aspect of the Garmin avionics.

Up til now, whenever I have selected and activated an RNAV approach with vertical guidance (LPV or LNAV+V), I have immediately seen the GS indicator appear and seemingly point to the FAF intercept altitude.  On the runway, the GS indicator is at the top, as I climb, it comes down, and when at correct approach altitude, it is at the bottom.

This time, as I was attempting to establish a feasible intercept altitude, I flew the approach outbound, and much to my surprise, as I passed the FAF outbound, the GS indicator kept rising.  I continued for a while, and turned around.  Now, I could fly the approach inbound from the IAF, with the GS indicator at the top, select APR on the autopilot, and intercept the GS well before the FAF, as it came down to meet me.

This was at KTPA, R1L LPV.   My approach altitude was 2000 feet, and I intercepted the glidepath at 2000 feet, much like in real life.

If I were to start at KPIE, and fly the approach as I normally would, at 2000 feet, the GS indicator would be at the bottom the entire time and I would not be able to intercept the glidepath unless I manually descended to something closer to 1400 feet.

Bert. I do not believe you said which gauge, default or mod, or all of the GPSs.

10 minutes ago, fppilot said:

Bert. I do not believe you said which gauge, default or mod, or all of the GPSs.

Sorry, this was in the G1000 equipped Bonanza, with the latest WT G1000 mods (0.3.5).

Edited May 2, 20215 yr by Bert Pieke

Next test... different airplane, GPS and airport, but same behavior.

Arrow, GNS530, CYCD RNAV R16 via HADER.

Fly at 1700 feet per the charts and watch the GS indicator at the bottom, until passing the FAF, at which point it jumps up to meet the airplane.  This we have seen before.

If you now turn the airplane outbound on the approach, back past the FAF to the IAF, the GS indicator no longer wants to sit at the bottom, but behaves correctly, rising to the top as you fly away from the airport.

If you wish, you can turn back again and intercept the GS at the correct capture altitude of 1700 feet.

Clearly, something gets reset when first passing the FAF... if WT can run this down, we may see a fix... 🙂

Could this be as simple as the GS indicator activating one waypoint too late?

In the real unit, the GS indicator activates when the FAF is the next waypoint... Here, the GS indicator appears to activate when passing the FAF and the runway is the next waypoint..

If this were FSX or P3D, I could track the GPS variables and give you the exact answer.. here I am looking at a black box..

This could be a one line coding change... and then one more to turn off the GS indicator before the IAF.

2 hours ago, Bert Pieke said:

If you wish, you can turn back again and intercept the GS at the correct capture altitude of 1700 feet.

Wonder if this is somewhat related to the 180° issue beyond the last flight plan waypoint with approaches.

3 hours ago, fppilot said:

Wonder if this is somewhat related to the 180° issue beyond the last flight plan waypoint with approaches.

I do not know...

You guys are basically talking amongst yourselves, which is nice, but I suspect that if you want to have feedback or bring these issues to the attention of the developers, you should post your concerns over on their Discord channel.

 

Our G1000 doesn't have any navigation or autopilot customization, it's all stock.

We'll be taking a look at these types of navigational issues as a whole over the course of this year in the sim.

-Matt

1 hour ago, MattNischan said:

We'll be taking a look at these types of navigational issues as a whole over the course of this year in the sim.

Matt,
Thank you for being attentive.  It is not a navigation issue.  It is an issue with modeling the GPS and AP.  Perhaps you should reach out to developers who have deep experience in implementing the actual Garmin Trainers with the full logic they embody.  What is the hangup there?  That technology in simulators has been around for over 10 years across all other available simulators.

Edited May 4, 20215 yr by fppilot

6 minutes ago, fppilot said:

Matt,
Thank you for being attentive.  It is not a navigation issue.  It is an issue with modeling the GPS and AP.  Perhaps you should reach out to developers who have deep experience in implementing the actual Garmin Trainers with the full logic they embody.  What is the hangup there?  That technology in simulators has been around for over 10 years across all other available simulators.

Why is this WT’s responsibility?  They made improvements to the Garmins as volunteers and for free.

12 minutes ago, Gilandred said:

Why is this WT’s responsibility?  They made improvements to the Garmins as volunteers and for free.

I did not say it is a WT issue.  Its an issue with the simulator.  WT is now working directly with the simulator developers so there is now a direct tie-in.  Conduit.

Edited May 4, 20215 yr by fppilot

Just now, fppilot said:

I did not say it is a WT issue.  Its an issue with the simulator.  WT is now working directly with the simulator developers so there is now a direct tie-in.

When you said “what’s the hangup there” that implied that they weren’t doing something they were supposed to be doing.  Perhaps I misinterpreted.

1 minute ago, Gilandred said:

When you said “what’s the hangup there” that implied that they weren’t doing something they were supposed to be doing.  Perhaps I misinterpreted.

That is based on the direct working relationship Asobo has formed with WT.  Now that is a team, together.  The overall responsibility, control of the SDK, and providing for 3rd party development is on Asobo. 

OMIGOD, the entitlement on this forum is through the roof.

22 minutes ago, fppilot said:

What is the hangup there?  That technology in simulators has been around for over 10 years across all other available simulators.

If I'm not mistaken the developer who is working - FOR FREE, VOLUNTEERING HIS TIME AND EFFORT -  on the Garmin's is posting as aznricepuff (sp.?) over on WT's Discord channel - subchannel "Garmin". He responds to user queries, so you should share your concerns/questions with him.