Skyview AP vs Trutrak

Thinking about autopilots for my 9A, and have always heard TruTrak is pretty much the gold standard by which all others shall be judged. But I'm planning a Skyview installation and the price of just adding on the autopilot servos from Dynon is certainly appealing, as is the savings in panel space. I'd really like my AP to be able to fly GPS and terrestrial-based glideslopes, and for now Skyview's capability to do that is vaporware. I've got time though, and I bet eventually they'll make good on that promise.

So those of you who are flying a Skyview autopilot, please tell us how the system is working out for you. Also valuable are any reports of using the Skyview AP in IFR conditions and any reports that can give an experienced direct head-to-head comparison between the Skyview AP and a TruTrak.

I know there are some differing opinions on why an autopilot should (or should not) be physically separate from the EFIS, and I'd rather not re-hash that debate unless someone has a first-hand horror story to tell about one configuration vs another. Thanks for any insight, guys and gals!

Skyview

TruTrak was the gold standard but many equally capable products have been introduced by others and all are very good. Dynon has been steady with software improvements since I bought mine last year; GPS navigation, flight plan, g-meter, etc. I expect glideslope following will be sooner or later but not a deal breaker.
Out of the box, my Dynon Skyview autopilot wandered around some in both roll and altitude. Just a little tweaking per the instructions and it is 99% as good in roll as it can be. Altitude is now stable within 20 feet of expected altitude and I just haven't taken time to try to make it better. Too much fun to hand fly.
TruTrak or Dynon (GRT or others), with any you can't go wrong.

Thanks, Dave. Is +/- 20 feet on altitude a good number? Seems to me that if one is flying a coupled glideslope 20 feet is a lot of error. Certainly don't mean any offense, just wondering what to expect performance-wise.

Anybody running a TruTrak want to chime in?

The +20 feet I think he is referring to is the 20' offset that I get all the time, i.e. 9000 set and it holds 9020'.

But it holds it rock solid. I fly it IFR and it performs VERY well indeed.

I think some later software revissions will fix the 20' offset. Not sure when though.

krw5927 said:

Thanks, Dave. Is +/- 20 feet on altitude a good number? Seems to me that if one is flying a coupled glideslope 20 feet is a lot of error. Certainly don't mean any offense, just wondering what to expect performance-wise.

Anybody running a TruTrak want to chime in?

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Have you ever flown a coupled GS with any autopilot? Some, even the certified ones will give you a wild ride! (typically on a real GS not a GPS derived one) The idea of coupled GS approaches sounds good but a ton of people that comment on them state that they would rather hand fly em. Since Dynon does not currently couple to any vertical guidance, it is difficult to compare to something that does not exist yet.

I can tell you that my Dynon based AP handles vertical decents based on vertical speed very well.

TT has a fine AP offering. Just make sure you get the model you need. Since the Skyview does not do any sort of data interpolation for GPSS enabled third party AP's, the AP will need to have native support for whatever source you plan to have it follow. This can make a huge difference in the price.

Brantel said:

Just make sure you get the model you need. Since the Skyview does not do any sort of data interpolation for GPSS enabled third party AP's, the AP will need to have native support for whatever source you plan to have it follow. This can make a huge difference in the price.

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Great point, and the primary reason I was leaning Dynon was the price. So far the comments I've heard have me pretty convinced Dynon would be the way to go for me. So tell me, if there's any folks flying Dynon glass that have TT autopilots, why did you go TruTrak?

Just a quick comment on the performance of TT autopilots. I regularly fly my friend's RV-7A with a TT Digiflight II VSGV with autotrim. I have done multiple LPV and LNAV/VNAV approaches in VFR and IFR conditions and it is rock solid on the VNAV path. I have let the autopilot fly down to as low as 50' agl and sometimes I think that if we had an autothrottle system and a flare mode it could autoland. I highly recommend a TT unit (currently in my almost completed RV-7)

Coupled LPV approaches are typically much smoother since the concept is much different. It is virtually impossible to compare the two different types of approaches when it comes to AP performance.