Spug

GNS530 V2 vertical guidance not working

Recommended Posts

Posted (edited)
3 minutes ago, RXP said:

both GTN and GNS V2 autopilot gauge code is the same so both are equally affected the same way, minor some 'nav' sequencing differences affecting mostly 'when' signals occur

If it is ok with the GTN but not with the GNS, maybe some of these signals occurring before or after make a difference. I'm looking very closely to all this to make sure.

Edited by RXP

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

15 minutes ago, RXP said:

If it is ok with the GTN but not with the GNS

I have not yet flown with GTN since before 2.5.14.

Share this post


Link to post
Share on other sites

@fppilot if you can do the same test flight with the GTN 2.5.14, maybe this would reveal whether there is commonality in the issues henceforth in the logic.

Share this post


Link to post
Share on other sites
2 hours ago, RXP said:

@fppilot if you can do the same test flight with the GTN 2.5.14, maybe this would reveal whether there is commonality in the issues henceforth in the logic.

OK, but probably not until sometime Monday.

Share this post


Link to post
Share on other sites

Yes. GTN 2.5.14 has the same characteristics in regard to coupling vertical guidance  for RNAV/GPS approaches.  I do not have the same C210 set up with a GTN.  I however flew the same approach with two of my GTN equipped aircraft, the Realair Turbine Duke v2 and the Milviz Cessna 310R Redux. 

In the TDv2, descending from 4000 at the IAF to arrive at a target altitude of 2100 before the FAF, and acquiring an LPV indication on the GTN, pressing the AP APR key armed APR mode and VS, but disarmed the AP ALT function.  I continued the approach and there was no vertical guidance.  The AP/GTN never leveled at the 2100 ft target altitude and did not acquire LPV guidance at the FAF.

I flew two additional approaches with the GTN equipped TDv2, beginning the approach just as above in the first approach.  Having learned from Spug's experience, upon acquiring the LPV indication and pressing the AP APR key, when the ALT disarmed I was able with additional AP key presses to get the AP to the right state for following the approach.  APR, ALT, VS and arm indications.  For both of these successful TDv2 approaches the AP key presses were trial and error.   It was not as simple as pressing the APR key twice, and I was not able to map a sequence to follow for future flights. It was try this, try that, until I got the AP indications I was looking for.  For me that is not a satisfactory result.

I then used the same approach with the Milviz C310R Redux model.  The KAP 140 AP in the Redux is a more sophisticated, shall we say, instrument.  I was not successful with either approach in the AP/GTN following vertical guidance. For this Redux KAP 140 AP it for some RNAV/GPS approaches requires establishing on the final approach course with HDG mode, then selecting APR mode after gaining acquisition of GPS LPV guidance.  That adds another layer of complexity to this current GTN and GNS issue that I just could not solve with two approaches.  I then attempted a 310R  approach to my familiar KBMG RNAV/GPS 35 with similar results. 😖 Not happy.

Share this post


Link to post
Share on other sites

@fppilot Thank you for the additional reports. They seem to confirm our findings during the week-end.

A quick update: I may have found out what is causing this and I'm doing my best to have a test build today or tomorrow to try. There was definitely a cross-over of code between our XPlane and FltSim version which is impairing each in a certain way. This plus some idiosyncrasies in each platform autopilot implementation which cannot be 'just abstracted out' as we've done in the last 2 or 3 GTN/GNS V2 versions.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now