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#1896149
Is there anyone on here who can advise on the degree of 'coupling' achievable between a legacy (= 'kin ancient) Piper Autocontrol 111 (wing leveller) autopilot and a Garmin GNS 430W please?

Our autopilot has recently been repaired and functions well in what I'd call 'basic' heading mode and will intercept/track a VOR radial but won't 'follow' a procedural approach (like an ILS.)

The Garmin displays the usual countdowns ( 'turn L to 160 degr in 10,9,8, etc seconds) but does not take up the displayed heading.
I pers have never seen it do this (I've always just used it in Hdg or VOR radial mode) and wonder if I'm expecting too much from this ancient bit of kit.

Opinions welcome.
Many thanks
Peter
#1896179
Flyin'Dutch' wrote:Yes, that is not possible with that set up.

As I understand it you'd need an autopilot with roll-steering for that.


But isn’t roll-steering the same as wing levelling? Or does it have rudder control ?

In the VOR radial intercept mode our AP certainty ‘steers’ , sometimes with hefty bank to intercept the radial .

I guess what I’m asking is why, when the 430W issues course change instructions in caption form with 10 second countdown in say an RNP approach in the form of heading to steer, why doesn’t it issue these instructions direct to the AP , which then executes the turn ?

I’m not talking about altitude keeping FAOD .
User avatar
By Dodo
FLYER Club Member  FLYER Club Member
#1896181
The Archer shareoplane I sometimes fly has a Century 21 autopilot of about the same vintage which I have never been able to persuade to do anything other than follow the heading bug, though others in the group assure me that it can follow a VOR Radial or a GPS course on the GNS 430 that was fitted until last month.

We've just upgraded from the 430 to an Avidyne IFD 440 which I understand is also connected to the autopilot, so I'll have another go when I next fly it.

Doesn't answer your question though.
#1896193
Dodo wrote:The Archer shareoplane I sometimes fly has a Century 21 autopilot of about the same vintage which I have never been able to persuade to do anything other than follow the heading bug, though others in the group assure me that it can follow a VOR Radial or a GPS course on the GNS 430 that was fitted until last month.


Doesn't answer your question though.



I think you sort of have answered it: I can get ours to follow heading changes as I dial them in and I can get it to intercept a VO R radial What it won’t do is follow course alterations in a GPS fpl or the extreme equivalent of following an procedural approach into say an ILS.

I guess if I want that, I’ll just have to turn hdg bug to indicated new heading each tim e but this could be a faff in RPN approach when time is short and it would be just as quick to do the ‘fly-by’ by hand.

Haven’t yet had the balls to allow AP to fly me down to 200ft on ILS as it’s only just come back from repair after 3 years of total unreliability . :shock:
#1896577
As I understand it you can get an interface box. Google "autopilot GPSS module". Maybe google "Icarus SAM" for one, "DAC GDC31" for another - as I understand it these are two which work with the Piper Autocontrol III (the Aspen PFD thing apparently does as well, but that's another layer up of panel changes!). From what I read, the autopilot has heading mode (responds to the heading bug) and CDI mode where it follows the CDI (from the VOR). What the GPSS module does is translate the GPS autopilot commands into a "turn left" or "turn right" voltage to send to the autopilot in heading mode, simulating the DI and heading bug sending varying voltages as to how off heading you are.

I know nothing about these though, only what a quick google would come up with!

https://www.aviationconsumer.com/aircraftreviews/gpss-retrofits-automation-to-the-max/

https://piperowner.org/talk/discussion/152863/gpss-to-century-ii-autopilot

https://piperowner.org/talk/discussion/151972/piper-autocontrol-autopilot-with-garmin-430w

https://aviation.stackexchange.com/questions/21577/what-are-the-differences-between-a-gps-coupled-autopilot-and-a-gpss-autopilot

https://www.pilotsofamerica.com/community/threads/another-panel-upgrade-thread-add-waas.47208/

If the GPS drives the CDI which the autopilot is coupled to, it can follow this, but from what is written in some of the pages above, it doesn't cope with course changes of more than about 10 degrees, so the GPSS module is the "proper" solution.

The Piper Autocontrol III is a rebadged Century II as I understand it, so you can google either with GPSS.

Quite a good video here:
https://www.dailymotion.com/video/x9sj7s

Also just saw this on e-bay...
https://www.ebay.com/itm/193789603095

Also just seen this. Peter H (337) might know something about them.
https://www.peter2000.co.uk/aviation/tb20-experience/gdc31.pdf

Oh, one more thing I've just noticed from googling, a G5 HSI can apparently act as a GPSS. Another edit, so can the GI275.
PeteSpencer liked this
#1943335
Paul_Sengupta wrote:Garmin G5/GAD29B to Piper Autocontrol III connections given here:

http://static.garmin.com/pumac/190-01112-10_17.pdf

See section 5.18.5.

For operation see section 4.1 below:

http://static.garmin.com/pumac/190-01112-12_C.pdf


Thanks for putting in the legwork Paul: I had read through both these and thought we were OK swith G5s but have received today an email from the (reputable) avionics outfit who have done a lot of work for us in the past including fitting the GNS430W, that fitting two G5s would require retention of legacy AH (which would have to be kept a place on panel ) if we want to drive the AP which seems to contradict the G5 Manuals.

Indeed in the Garmin GI275 manual stuff it does mention shortcomings of G5 wrt some autopilots that the GI275 will overcome.