Using an HS34 and AP74 Together

[speeddog7]

I have a D180 with HS34. I'm about to purchase two servos and an AP74. I recall reading somewhere that the HS34 has the capability of controlling most of the autopilot features. What additional features would the installation of the AP74 provide over just using the HS34?

A bit confused,

Chad

 

[agrantz]

Chad,
The AP74 is a very useful component of the AP system. It allows you to engage/disengage the AP, and select HDG, TRK, NAV modes as well as ALT. Without the AP74, you would be constantly going into the menus of the EFIS to toggle these choices. The only component of the AP74 I don't use is the value knob. That's because the value knob on the HS34 performs exactly the same function. In my aircraft (an RV8) I've located my HS34 directly below my D10A (which I use exclusively in the HSI mode). The AP is off to the side and a little less accessible. If I didn't have the AP74, I'd be constantly toggling thru the AP menu to change HDG, NAV and ALT. If you plan on flying IFR with this AP, The AP74 is a must, as there is a lot of toggling between HDG,NAV and ALT.

-Alan

 

[dynonsupport]

The AP74 and HS34 are actually pretty independent. You can control bugs with the HS34, and those bugs do control the AP, but only if the AP is already engaged in the right mode. You can't change AP modes with the HS34, only with the AP74 or in the EFIS menus. So if all you have is the HS34, you'll need to go into the EFIS menu to engage, disengage, or adjust modes, but once the AP is on, you can use the HS34 to make changes to your altitude or heading.

 

[speeddog7]

Alan (and Dynon support), I really appreciate the information. Sounds like I definitely need the AP74 for the type of flying I like to do. Again, thanks for the information.