D180+HS34+AP74 - both needed with only one GPS?

[jbrady]

For our RV-8 under construction we bought a D-180 with 2 servos and an AP34.  Having now read the product documentation, studied the configuration and discussed options with tech support we realised we needed an AP74 to achieve the AP functionality we wanted (just like an Airbus please).  We have now received the AP74 and have studied the documentation for that too.  

We bought the HS34 as documentation suggests we need it to integrate GPS navigation.  However, as a single GPS will be the only navigation equipment in the aeroplane, the AP74 documentation sort of suggests we can couple the GPS through the AP74 using the NAV button/function.  We don't need an HSI presentation on the EFIS; we just want the AP in NAV mode to intercept and follow the route loaded in the GPS (like an Airbus).

Question for tech support - can we achieve GPS route navigation as described using the D-180 and AP74 only and dispense with the HS34?  It would help our panel layout if we can do that but we do need HDG, TRK and NAV functions from the single GPS source.

Many thanks in advance, John

 

[dynonsupport]

Re: D180+HS34+AP74 - both needed with only one GPS

The AP74 is just a set of buttons, period. With a NMEA GPS connected to to the D180, you can fly NAV/HDG/TRK. So the AP74 is primarily a better user interface to the autopilot. When you get down to the nitty gritty, the AP74 lets you do things like pre-arm modes, but that's a little beyond this discussion.

The HS34's UI is all about HSI control, but it also has the hardware inside to be able to receive all information from a GNS 430/530/similar. If you have one of those, you want the HS34 for that hardware capability, else you won't be able to fly a VOR or Localizer with the AP.

Assuming your GPS is not a Garmin 430/530 and you don't care about the HSI features, keep the AP74 and ditch the HS34. Give us a call at 425-402-0433 if you need some more explanation.

 

[jbrady]

Re: D180+HS34+AP74 - both needed with only one GPS

That's really helpful thanks folks,

We are not going to install VOR, ILs or any other radio navaid nor do we have a Garmin 430/530 so we don't need any of that functionality.  We have a single Flymap F7 GPS http://www.pioneeravionics.co.uk/product.asp?i=145/GPS which impliments NEMA messages and I have checked with the manufacturer that it provides the messages that the Dynon requires.  Does that confirm your advice that we can omit the HS34?

John

 

[Brantel]

Re: D180+HS34+AP74 - both needed with only one GPS

Sure with one plain NMEA GPS you do not need the HS34 but it sure does make it nice for more dedicated KNOBS.....You can configure the first action of the value knobs on the HS34 and the AP74 to different functions and that is really nice.

It is an expensive option though just for extra knobs.

If money and panel space are not the issue, I would put it in anyway...I did even though money was a problem

 

[PhantomPholly]

Re: D180+HS34+AP74 - both needed with only one GPS

Conversely, if you are willing to push extra buttons it is my understanding that the AP74 functions are all available through the soft menu. Since you aren't using an approach GPS, it seems likely that you really don't care about most of the advanced functions of the AP. Thus the knobs on the HS34 may be of more use to you (Altimeter setting, heading bug, etc.) than the AP74.

It's a tough call, but remember you can add later if you want to. My recommendation would be to get flying without either one, and see what bugs you most (if anything). If nothing bothers you (personally I would go nuts setting the Altimeter with the buttons - but it wasn't really an option for me anyway as I fly IFR with a GNS-480) then I would save the money.

 

[Brantel]

Re: D180+HS34+AP74 - both needed with only one GPS

The AP74 Value knob can do the same functions as the HS34 value knob.

Without the AP74, you cannot pre-arm modes and preselect altitudes/headings like you can with the AP74.

Either one also enables automatic dimming of the system if you want it and Voice Alerts.