Not to hijack Jason's thread, but I have a Tru-Trak Digiflight II VSGV. I chose the "flat pack" version due to limited available panel space. My radio shop connected the a/p directly to the 430W so the Aspen doesn't provide any signal to the a/p. The GPSS button on the Aspen doesn't do anything on my setup. So I can't give any advice on an Aspen-a/p interface. I do like the quasi-independence, though (GPS is still common to both). Plus I have full vac powered panel on the co-pilot's side in case the Aspen dies. Belt & suspenders approach I suppose.
I looked at the Dynon-10A unit early on, but two main things kept me from going that route. 1) At the time the Dynon unit had no vertical guidance indication and I wanted something that supported approaches, 2) I was looking to replace my electric DG with an HSI. To me it was worth the additional the cost to go with the Aspen. I know other owners of my airplane type have the Dynon and are quite happy with it. I also know several builders that have installed the Aspen unit and are happy with it. My shop reports they have one customer that put it in an aerobatic plane and it will need to be "reset" in flight after extreme manuevers, but the unit itself tolerates the unusual attitudes with no permanent damage.
If you have an older "certified" a/p using the Aspen to "drive" it would be an advantage, but the Tru-Trak unit I have is so capable as a stand alone unit (with GPS input) it really wouldn't benefit from an Aspen interface in my opinion. I can't say enough good things about the Tru-Trak unit. From calibrating itself automatically during the initial functional check flight (the Aspen requires "swinging" the compass on the ground) to flying coupled LNAV/VNAV/LPV approaches and smooth GPS steering it's taken a lot of workload out of flying IFR (and VFR). The unit I have also provides "dial in" rate of climb capability and will "hold what you got" when you engage it, which comes in handy after you stabilize your initial climbout manually. My Flightaware flight tracks are much straighter now, too!
I probably would have gotten the Sorcerer since it will do coupled VOR/ILS/LOC in addition to GPS approaches, but I just didn't have the panel space without some major metalwork.
I met with the company president of Aspen at Airventure in 2008 after I had had some teething problems with their initial release unit. They prefer to work with their dealers rather than provide direct support, even for "certified" installations, but they were very helpful in resolving some early problems with the unit. There's been a "non-mandatory" software update since then that has eliminated all the glitches I was experiencing. I have the same ADHRs unit as originally installed, but I did go through 3 display units until I got one that operated reliably under all conditions. The problems were primarily with the bus voltage threshold for switching to internal battery and the deck angle of the ADHRS relative to the panel mounted unit. Aspen found that on some taildraggers (and my plane has a fairly steep taper towards the tail, although it is a nosewheel) the ADHRS attitude on the ground was exceeding the unit's calibration limits. That deck angle limitation has since been resolved. I have to thank Mid-South Avionics at KTCL for working through the problems. They support experimental and factory installations and have gone the extra mile to keep me happy. They also did my Garmin stack and the final hookup of the Tru-Trak.
I know a couple of RV-8 owners that built their planes with a hole in the panel to accept the AP-76. Don't know what they're going to do with that now.
Can you tell me a bit more about your Tru-Trak and how it plays with the Aspen? Which Tru-Trak unit do you have? I have a Tru-Trak ADI-II that I love (love the ADI, would like more capability in the AP) and have it coupled to a Garmin 430W. If I want to go glass without completely reconfiguring my panel, the Aspen seems to be the best choice. Problem is, they've expressed NO interest in supporting experimental A/P when I've discussed it with them in the past. When Dynon came out with A/P and AP-76 controller last year, I was really excited - a perfect solution. Now that they've killed the AP-76, I'm thinking it would be better to go with the certified Aspen. But now I'm stuck with a lower level of A/P capability unless I want to upgrade there. I'd love to know how your setup is working for you.
VFR, well... Who cares?
