J

jscottpilot

Active Member
My neighbor just installed the GRT synthetic vision system and wants me to test it and learn to fly it so that I can teach him. I have 10,000 hours in jets with EFIS systems and this thing does not act like anything I have flown. I suspect that there is a problem in the installation. Probably with the interface between the autopilot and the Garmin 396. Has anyone used one of these things that might be able to help me?
 
I've got lots of hours behind the HX without any trouble - what, in particular, doesn't seem right to you?
 
The hx is connected to a garmin 396 and an appropriate tru track autopilot. 1. The HX system will not go direct to a waypoint when I select it. It has to be done through the garmin 396.

2. When I use the heading bug to to control heading the autopilot will not follow the HX system. The only way to hold heading is via the autopilot heading hold function.

3. I have the same problems with the altitude hold. I cannot make the autopilot follow the hx system. I can only control altitude with the autopilot controls not through the hx system.

There are other things I dont understand about the system but I need to figure these out first and the others will probably be easier to overcome.
 
jscottpilot said:
The hx is connected to a garmin 396 and an appropriate tru track autopilot. 1. The HX system will not go direct to a waypoint when I select it. It has to be done through the garmin 396.



2. When I use the heading bug to to control heading the autopilot will not follow the HX system. The only way to hold heading is via the autopilot heading hold function.



3. I have the same problems with the altitude hold. I cannot make the autopilot follow the hx system. I can only control altitude with the autopilot controls not through the hx system.

There are other things I dont understand about the system but I need to figure these out first and the others will probably be easier to overcome.
Click to expand...

1-It sounds like you need to select 'GPS 2' on the HX (or GPS 1 - depends on how yours is configured). To do this simply press one of the buttons on the HX from the PFD page. Then, press it again until you see 'GPS1/GPS2' displayed. Then, press the button under 'GPS1/GPS2' to toggle from one to the other. Again....it sounds like your TT is simply doing what it's told to do.

2-Simply push the 'mode' button on the TT to change it to 'GPSS'. The make sure the HX is set to 'HDG'. You'll then be able to steer the plane using the left knob on the HX. You might want to press BOTH knobs at the same time first, this aligns the heading bug with the current track. Also, If you want the AP to take you directly to your next waypoint, just change the HX from 'HDG' to 'ENAV'.

These things are actually quite simple to use. I've called Carlos and Sandy many times and they have NEVER failed to help me or impress me. That said....one of the best pieces of advice Carlos has given me was to read the 'User Manual'....."Teach a Man to Fish" :rolleyes:.

The 'User Manual' is on the GRT web site:

http://www.grtavionics.com/File/User Manuals/Horizon User Rev C Feb 2009.pdf

Good Luck.
 
Rick's post starts to sort things out, but before you get too far into frustration, I'd need to ask a few more questions.

1) Which "appropriate Tru Trak Autopilot"? just about any of their systems will work with the GRT stuff, and it can be a very simple heading-hold/Nav Trak using Serial data or a full-up VSGS with ARINC and GPSS. How you operate it will depend on which autopilot.

2) Is there an internal GPS as well? How are the GPS's configured? Is the 396 connected to GPS 1 or GPS 2 in software, and are the serial ports properly configured?

3) Is the setup within the HX correct? These things are very "configurable" - which gives you a lot of capability, but also a lot of ways to not get them set up properly. I have helped a lot of people set up their aircraft with GRT equipment, and so far, have never met two identical configurations.

Until we know how the hardware is connected in that particular aircraft, and then how it is configured, everything else is a guess. It doesn't take long to get set up once we know that - but until then, it's almost impossible to predict how it will work.

Paul
 
One other consideration - from his description it sounds like the data out wire from the x96 is split and runs to both the HX and the TT autopilot. If this is true, no configuration of the Horizon will correct the situation.

In order to take advantage of the EFIS autopilot features, the TT signal must come FROM the Horizon, not the GPS. Otherwise, nothing you do on the EFIS will affect autopilot functions at all.

Sadly, the TT is only designed to accept a single set of GPS inputs. Many users install a switch to determine which GPS (or in this situation, whether the GPS or the EFIS) controls the autopilot.
 
A switch has been installed to switch between the two systems. I still cannot get the EFIS or the autopilot to track to a waypoint. The owner is going to take the garmin 396 out and install a garmin 430. We are going to test fly it again. I am sure that that some of the general settings are wrong but I still cannot figure out what they should be. I have read the users manual for the auto pilot and the hx.
 
If you are putting in a 430, I have all the wiring and internal settings.

I have a GRT 8.5HX, 530, 430, 330, 340, Trutrak VSGV all interconnected and all working great..!!!!!

I switch between the GRT & the 530 to the autopilot.

Some of the internal settings from GRT were wrong (NO big deal). The settings have to be matched to the way you wired it.

PM me
 
Last edited:
jscottpilot said:
A switch has been installed to switch between the two systems. I still cannot get the EFIS or the autopilot to track to a waypoint. The owner is going to take the garmin 396 out and install a garmin 430. We are going to test fly it again. I am sure that that some of the general settings are wrong but I still cannot figure out what they should be. I have read the users manual for the auto pilot and the hx.
Click to expand...

If he's doing a rewiring job, make sure to get an actual wiring diagram so that we know which channels on the Garmin are connected to which channels on the GRT - without that, it is all going to be trial and error figuring it out how to configure the system. I've set up lots of systems, and no two have been alike.

Paul
 
You must log in or register to reply here.