Avionics: Digital Autopilots

Five Years Later

By Bob Hart

www.AvionixHelp.com

The summer of 2017 brought what I described as some of the best news I had heard in my 20+ years as an avionics consultant on behalf of Legacy aircraft owners.  That was the announcement by four companies that they were now offering new digital autopilots for the GA market.  While I recognized that the Garmin GFC 500 and GFC 600 and the Genesys/S-TEC 3100 were a step-up for the more serious IFR crowd, it was the announcement by Trio and TruTrak that an affordable, digital autopilot was now available for the VFR and Light IFR pilot.

Prior to this, upgrading a tired legacy autopilot was financially out of reach for many.  Trio and TruTrak changed that in 2017. That was five years ago, and I thought it might be a good time to revisit these autopilots.  While I have my own observations and opinions, I decided to reach out to a few avionics shops that I know well for their opinions and experience and I was surprised to find some strong opinions, both positive and negative.  That encouraged me to reach out further to get a broader perspective.  When I write, I tend to keep it positive however, the shops I spoke to, some smaller shops, some high volume, have had some less than positive experiences with these autopilots and I feel I would be remiss if I didn’t include these comments in the article.  So, let’s look at each manufacturer (in alphabetic order) and I’ll share the feedback I got when I asked them how they felt about the new digital autopilots introduced in 2017.

Bendix King: AeroCruze 100 (formerly TruTrak) and the AeroCruze 230

TruTrak has been making autopilots for the experimental-Light Sport market for years and through the efforts of EAA STC, they received the STC for certified aircraft in 2017.  The autopilot was well-received by legacy aircraft owners and much to the surprise of myself and the industry, Bendix King announced that they were buying TruTrak in 2019.  Frankly, this announcement was not as well received. The first year of transition from TruTrak to BK was less than smooth with incomplete orders, slow response to problems and a lot of the “good will” created by Andrew Barker and TruTrak were lost in the haze.  While the shops I spoke to were generally okay with installing the AeroCruze 100, I found no enthusiasm for Bendix King and the majority of shops were no longer Bendix King dealers.  I would suggest that the majority of pilots who have the AeroCruze or TruTrak installed, who made it through the haze, are happy with their AeroCruze 100. It’s a full featured, digital autopilot designed for the VFR or Light IFR market.  The AeroCruze 100 is about $5900 with STC, and I’ve seen install labor discussions from 20 hours (ridiculous) and up.  I would suspect that 40-50 hours will be a typical shop labor quote for the AeroCruze 100 with removal of a legacy autopilot. 

The AeroCruze 230, was also introduced in 2017 by Bendix King, as an upgrade to their KFC 150 (and now the KFC-200).  The KFC-150/200 were a popular OEM autopilots found in many new aircraft and generally had a good reputation. One weakness, which showed up later was the vacuum, mechanical KI-256attitude indicatorthe provided position-sensing for the autopilot.  BK introduced an electronic alternative to the KI-256 in 2017 in the form of the KI-300, made for Bendix King by Sandia Aerospace, which has been less than stellar.  The concept of the AeroCruze 230 is as a direct replacement of the original KFC-150/200controller and to reuse the existing servos and harness providing a simple, affordable digital upgrade.  Only one of the shops I spoke to has installed an AeroCruze 230 and it is not performing as advertised and the shop suggests that BK is being less responsive to his customer than he would hope.  He will not be installing another one. In short, none of the shops I spoke to have any plans to sell Bendix King products.  If I have had any concern about the AeroCruze 100 autopilot, it is about the future of Bendix King and the support that might not be there in the future for AeroCruze owners.  STC’s for new models of aircraft seem to me to be moving slow.

Dynon Autopilot.  A few of the shops mentioned the Dynon Autopilot and their only complaint was that STC’s were not coming fast enough.  I said it in my previous articles, and I’ll say it again. If you are in the market for large format EFIS and … need engine management and a modern, digital autopilot, the Dynon Skyview system is a great value.  These shops agree and they see the quality in the equipment.   It was not one of the autopilots introduced in 2017 but I would be remiss if I did not include it here. 

Garmin:  GFC 500 Autopilot

Unlike the Light IFR AeroCruze 100 I mentioned above, the Garmin GFC 500 is “state of the art” in a True IFR autopilot and all of the shops I spoke with agree it is leading the pack!  However, and we don’t really expect this from Garmin, the path has not been without some speedbumps and in the case of the GFC 500, that has come in the form of significant servo failures.  Every shop I spoke with has had servo failures with the GFC 500.  One shop did a GFC 500, three servo installation (with autotrim) and saw all three servos fail in the first six months.  Garmin issued a Mandatory Service Bulletin in February 2022 that resulted in the exchange or repair of their GSA28 servos in the field and shops report that this is no longer an issue.  It was also reported that even with Garmin’s supply chain issues that are delaying delivery (at the time of this writing) of some of their most popular products, the GFC 500 is available, the G5’s and GI 275’s that are required to drive the autopilot (in lieu of a G3X or G500Xi), not so much.  All in all, Garmin’s GFC 500 is the popular choice between the new digital autopilots targeting the True IFR pilot as confirmed by all the shops I spoke with.  What stands out for me, vs. the Genesys 3100 is the value.  At approximately $26,000 installed including autotrim (with a third servo), the GFC 500 upgrades your autopilot and also your Attitude Indicator and HSI. The Genesys 3100 requires you to address these important instruments separately which is very desirable in True IFR.  

Genesys/S-TEC 3100 Autopilot

Genesys also introduced their New 3100 Digital Autopilot at Oshkosh 2017 and while the autopilot stands alone, with all new servos and harness, Genesys is also marketing it as an upgrade to the System 55X (and previous models) where you keep your original servos and modify the harness.  The same shop that has had issues with the BK AeroCruze 230 (using original servos) is also less than enthusiastic about the 3100 installation, when using original servos.  He had two installations where the 3100, installed with original servos, were actually removed and replaced with the Garmin GFC 500. He also noted that he had two clients who were happy with their 3100 but in both of those cases, new servos were installed.

More than one dealer mentioned that Genesys had requested that the aircraft owner fly the plane to Mineral Springs, TX, in order to get the system working correctly. Unlike the GFC 500 which uses external solid-state position sensors (either the G5 or the GI 275), the Genesys 3100 has an internal AHRS and requires no external sensors.  It also appears that Genesys is backing away from their popular analog System 20 single-axis autopilot and their System 30 with Altitude Hold (about $18K installed).  It appears that the BK AeroCruze 100 and the Pro Pilot from Trio Avionics has had a significant effect of that segment of the market which, simply stated, is legacy aircraft owners flying affordable airplanes upgrading their legacy autopilots.

Trio Pro Pilot Autopilot

Both the Trio and TruTrak autopilots came to market at the same time in 2017 but it appears to me that Trio was a little slower getting the message out and that TruTrak had the early marketing advantage.  Unlike TruTrak, that manufactured and marketed their autopilot in 2017, Trio uses two entities.  Trio manufacturers and supports the autopilot while the STC Group is responsible for engineering, including the original certified STC and subsequent STC’s and they also handle sales for Trio.  Trio had some issues early with servos that needed a boost in certain airframes and that was addressed a few years ago. New management at the STC Group seems more aggressive at building new dealerships and is moving forward with adding STC’s.  One shop I spoke to has chosen to stay away from the BK AeroCruze and recommends the Trio for those pilots looking for an affordable, digital autopilot. This was based on a general concern about Bendix King and what he described as a lack of dealer support. He went out of his way to point out that his support from Trio and the STC Group had a lot to do with that decision. Pricewise, the Trio Pro Pilot and the BK AeroCruze are about the same at about $6000 for equipment and STC.  A comparison of features and benefits of the two autopilots is similar with the Trio offering a few features not found in the AeroCruze like “track offset”.  Some pilots prefer to offset their track on busy airways and the Trio can do this.  Trio’s “straight and level” button can also be programmed to do a coordinated 180 degree turn, a feature that a VFR pilot might like if they mistakenly enter into IFR conditions.  In my consultant work with pilots planning an avionics upgrade with Light IFR in mind, I recommend the Trio Pro Pilot for the same reasons.  As I mentioned above, none of the shops I spoke to have any desire to sell Bendix King products, and some no longer are BK dealers.  This does not bod well for the future of Bendix King and the AeroCruze.

Conclusion

Any pilot who will find themselves in IFR conditions, especially low-time light IFR pilots with their families, who occasionally fly IFR, should have an autopilot.

I used to say, “at least a basic autopilot”, but that game has changed.  The legacy aircraft owner upgrading from a tired factory installed, single-axis autopilot with plans to fly Light IFR now have the choice of two, very sophisticated options in either the Trio Pro Pilot or the Bendix King AeroCruze 100.  Funny … Honeywell, the parent company of Bendix King, in their marketing, refers to the AeroCruze 100 as “basic”. The AeroCruze or Trio Pro Pilot are anything but basic! The legacy S-TEC System 20 “wing leveler” and even the System 30 with altitude hold could easily be defined as basic by today’s standards.  Pilots flying True IFR have the Garmin GFC 500 including solid-state electronic flight instruments and the Genesys/S-TEC 3100 option.  Whether it be marketing, overall performance or value, it appears that the GFC 500 and the Bendix King AeroCruze 100 are leading the pack today.  I expect the Dynon Skyview system with Autopilot (and Engine management) to be a serious contender as more STC’s for their autopilot become available.  Frankly, I’m rooting for Trio, and I think in time, their customer support will make the difference.

Until Next Time … Safe and Happy Flying!

Bob Hart

www.AvionixHelp.com