Auto pilot odd behavior

[MartinRex007 390]

I'm having some odd moments with this AP. Before takeoff I set the Alt Alert to say 9,000ft and arm it, then hit the FD and HDG on the AP. Takeoff set things up for climb out and hit the AP on the mode selector and nothing happens in either the VC or popup, only way to get the AP on is to hit the Z key.  At this point everything seems fine. The problem happens when I hit Nav on the mode selector to follow my GPS route in the GTN750. Nav lights up along with Nav1 and GS? Then my pitch goes crazy and the plane goes into a sharp climb and stalls. Any insight into what might be going on would be very much appreciated..

Thanks

Martin

[mikebxb 20]

5 minutes ago, MartinRex007 said:

I'm having some odd moments with this AP. Before takeoff I set the Alt Alert to say 9,000ft and arm it, then hit the FD and HDG on the AP. Takeoff set things up for climb out and hit the AP on the mode selector and nothing happens in either the VC or popup, only way to get the AP on is to hit the Z key.  At this point everything seems fine. The problem happens when I hit Nav on the mode selector to follow my GPS route in the GTN750. Nav lights up along with Nav1 and GS? Then my pitch goes crazy and the plane goes into a sharp climb and stalls. Any insight into what might be going on would be very much appreciated..

Thanks

Martin

Which GTN750..Flight1 or RealityXP?

 

[MartinRex007 390]

Fligh1 and I changed the aircraft to 4 in the .ini as mentioned earlier by Bert?

The only thing I can think of is maybe when I hit Nav it used Nav2 which it looks like it defaulted too and that messed things up, I'm trying another flight to see if that was the problem.

I'm probably doing something wrong, but couldn't find any documentation from Alabeo.

P.S. is there a way to set the default Nav to Nav1?

Edited June 6, 2018 by MartinRex007

[Bert Pieke 7,584]

Couple of things..

The AP indicator on the autopilot control panel is just that, an indicator.

The AP on/off switch is on the lower console (or you can use the Z key, as you discovered).

The GS light should only light up if you have a vertical signal on the HSI, ie a glideslope..  This could happen if the GTN is in VLOC mode and you have an ILS frequency dialed in, or if the GTN is in GPS mode and an LPV approach is active..  If this occurs again, post the details!

The upper right switch is the NAV1/2 switch!  The NAV on/off switch is the middle switch.  You'll get used to it..  Agree that some documentation would come in handy!  I purchased the factory autopilot manual, so if you have detail questions, contact me via PM..

[MartinRex007 390]

Bert,

Thanks for this info, yes I thought it odd that GS would show up when I hit Nav, will continue to run some test.

Cheers

Martin

[MartinRex007 390]

I took of from MMLT with no other airports around for miles and same thing, when I hit Nav to track my GPS route, for some reason the GS indicator comes on and the plane loses pitch control and stalls. Nav2 also comes on, but I can quickly hit Nav1 instead but can't seem to do anything with GS being on?

Thanks Martin

[Bert Pieke 7,584]

The GTN has an active flight plan and is in GPS mode, correct?

I'll test and see.. worst case request my GTN panel via PM (with your email address) as a test.

[MartinRex007 390]

Correct, a GPS route I do often in other Carenado aircraft with no problem.

Thanks Bert, let me try one more thing.

[Bert Pieke 7,584]

Strange, I just tested the unmodified V1.1. version and VOR and NAV1 lights up, as expected.

[MartinRex007 390]

Whenever I hit the Nav switch to follow the GPS route the GS comes on, Nav1 lights, and GPS set correctly....once the GS lights the plane loses control.

I sent you a PM

 

Thanks - Martin

[MartinRex007 390]

The AP800B works fine when using a VOR as your Nav source, but when I try and use the GTN 750 GPS as the Nav source is when the GS comes on and everything goes crazy...ugh! Back to the good old days of flying from VOR to VOR!  Off too Vegas to attend the Expo, should be fun!

Cheers

Martin

Edited June 7, 2018 by MartinRex007

[Bert Pieke 7,584]

54 minutes ago, MartinRex007 said:

The AP800B works fine when using a VOR as your Nav source, but when I try and use the GTN 750 GPS as the Nav source is when the GS comes on and everything goes crazy...ugh! Back to the good old days of flying from VOR to VOR!  Off too Vegas to attend the Expo, should be fun!

Cheers

Martin

This must be fixable.. it works just fine on my system..

Let me know when you return!

Enjoy Vegas..

[MartinRex007 390]

Thanks Bert, will do!

[AndiKunzi 62]

That behaviour is realistic. Those old 800B autopilots are known for their strange failures and it is difficult and expensive to repair them. 

[rightseat 277]

21 hours ago, AndiKunzi said:

That behaviour is realistic. Those old 800B autopilots are known for their strange failures and it is difficult and expensive to repair them. 

Sure would be nice if someone could drop us an STec in there with preselect. I used to have FS panelshop, but I don't know if it still works for P3d... 🙂