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View Full Version : Dynon AP v.s. Tru-Trak


Wesael
03-31-2010, 04:39 PM
Can anyone give me a detailed discription of there flying experiances provided you have flown behind both systems.

I really want a compairison of the systems. Not just your experiance with one or the other.

Thanks in advance!!!

Jamie
03-31-2010, 07:43 PM
Ok, not sure what you are looking for but I have flown both in my airplane. I posted a thread (http://www.vansairforce.com/community/showthread.php?t=42161&highlight=gauntlet) on my experiences a while back.

Wesael
03-31-2010, 09:05 PM
I looked and searched this forum but somehow missed your post.:confused:

Wow! thanks for the link that was exactly what I was looking for.:)

Lycosaurus
04-01-2010, 06:24 AM
Ok, not sure what you are looking for but I have flown both in my airplane. I posted a thread (http://www.vansairforce.com/community/showthread.php?t=42161&highlight=gauntlet) on my experiences a while back.

Jamie,

In all fairness, Dynon has just released firmware Ver. 5.3. It is supposed to address roll oscillations that some people have. I asked on the Dynon support forum if anyone installed 5.3 yet and tested the autopilot. The response was positive.

The Dynon autopilot is packed with features, and the price is right too. My only issue now is roll oscillations or wandering (depending on settings chosen). I'll be (hopefully) updating the firmware this weekend and testing out the improved autopilot performance. Crossing my fingers.

Jamie
04-01-2010, 07:22 AM
Yep, the thing could work perfectly now. My experiences were early on. However, the autopilot didn't just oscillate with me...it didn't work acceptably at all.

I did fly in another RV-7A recently that had the Dynon AP installed. The performance in that plane was better than the Dynon AP in mine, but in my opinion it was still not up to snuff. To me ideal performance for an AP is:

1) Not being able to feel the AP in absolutely smooth air
2) having the AP correct smoothly but promptly when attitude is disrupted in turbulent air.
3) Maintaining altitude +- 10 feet.
4) Flying your GPS flight plan += 0.02 NM in smooth air.

His plane met none of those criterion.

We tried adjusting his "sensitivity" settings in flight. Bump one notch down and it would not hold altitude at all. Next setting up and you could feel every movement it made. It's almost as if it corrects too late.

Once back on the ground we swapped rides so I could show my friend how the Trutrak performed. "I guess I have more work to do on the autopilot", he said.

Looking at the latest Dynon manuals, it appears that they are still missing all of the tweaks and settings that the Trutrak has that allows you to customize the AP to your plane. Check out the manuals for yourself and look at the all of the tweaks the Trutrak has. Dynon has "Sensitivity" (gain) and "Torque" for each axis.

I honestly think a lot of the Dynon AP fans have simply not flown a Trutrak recently.

I will reiterate another difference between the companies. Unless things have changed, Dynon does not have an aircraft testbed to actually test their code...they rely almost entirely on beta testers to give them feedback. Not so with Trutrak.

Sorry, my intention is not to throw mud at an outstanding company (I have a lot of respect for Dynon and my EFIS and EMS continue to be my favorite instruments in my panel). These are only my personal observations.

slyfox
04-01-2010, 08:11 AM
I know you mentioned that you don't want responses of people that just flew one type. But here goes anyway. I had the dynon ap in my aircraft and had the same issues that jamie had. I was very dissapointed. I went and removed the ap and now have just the mounting brackets waiting for me to purchase a digiflightII (trutrak) system which will be tied into my 430w that I want to put in the airplane. Just go and read the post that Jamie put in, which it sounds you did and that is what happened to me. I want a sound system that will work for IFR, the DYnon system was NOT going to work for me, so I removed it.:(

Brantel
04-01-2010, 08:20 AM
Hopefully Dynon will continue to work on the AP. My guess is the Skyview is taking priority over there. Looks like the latest release helps some on the roll axis but does nothing for the pitch.

Like Jamie, I think Dynon is going to have to give the end user more control over the AP. Gain and Torque just ain't enough...

I put a AP74 in my panel since I already had a big hole cut for it but I have not installed servo's yet.

Dynon might be smart to take a look at the TT manuals and think about some of the things that TT allows the end user to tweak.

A good working AP will be key to making the Skyview successful and the algorithms and end user settings should be easy to port back and forth between the legacy and new stuff. The servo's are common between them after all. That being said, I think Dynon will get the AP out of diapers some day.

kentb
04-01-2010, 10:51 AM
I started flying my plane with Blue Mountain EFIS/AP. Although not a Dynon, I believe that from a systems point of view they are similar.

I have sense replaced the AP with a TT.

I feel that there is an system level flaw with having the AP being dependant on the EFIS.

In the BMA system the smarts for the AP is in the EFIS. As software in the EFIS was changed the AP would preform differently. If the EFIS got upset or crashed the AP would go strange. I have had to grab the stick a number of time to keep the AP from pitching up and right back as hard as it could. Luckily it never did this with a passenger on board.

With the TT if the AP loose communication with the controlling device (EFIS or GPS) the AP continues on with a bearing and alt hold. The software is very mature in the TT and there are a lot of plane flying without any reported problem.

Dynon may preform well, but I still think there is an issue from the point of view of system design.

Kent

jerryab
04-01-2010, 11:01 AM
I've been flying 43 years and have owned well over a dozen aircraft, all with autopilots. I have never experienced any autopilot that works as well a my TruTrack. It is the EFIS autopilot, but all of their a/ps are noted for reliability and functionality. TT support is there and always anxious to resolve any problems or questions. I've never had a problem, but have had a few questions. Lucas is great at TT.

Jerry Martin
N331RD

Jamie
04-01-2010, 11:18 AM
Agree about Lucas. If every company had a Lucas getting great customer service would never be an issue.

Leland
04-01-2010, 11:33 AM
I installed the Dynon autopilot system with a D10A running 5.2 software. I finished the installation in early March and now have ten hours on it. It took me a while to learn how to correctly set the Garmin 296 output. The Navigation feature works extremely well in both smooth and turbulent air. The Heading function works perfectly in smooth air but wanders and shutters somewhat in turbulence. The problem is probably that my remote magnetometer was not placed in the best location and its angles are not adjusted accurately. I can tell there is a problem with the magnetometer because the D10A does not display the correct winds aloft. I am still using the factory settings in the D10A.
Leland
450 hours on an RV9A

TrutrakTech
04-01-2010, 01:40 PM
Agree about Lucas. If every company had a Lucas getting great customer service would never be an issue.

Thanks for the kind words. I really appreciate it. It makes the job that much more rewarding!

flickroll
04-01-2010, 02:08 PM
I had a Dynon AP in my -8, controlled by an AP74 and a D100. I considered it a decent VFR AP but never trusted it for IFR flying. It did a great job navigating in NAV mode off a G696; it was usually spot-on course. It would wander on heading +/- 3 or 4 degrees or so (not really an issue for me because when I used the AP it was almost always in NAV mode), and would usually hold altitude +/- 20'. The part that was unacceptable to me was it seemed that almost every flight I was having to jack around with sensitivity settings to adjust for changes in daily air conditions to get the performance I desired which IMO was a non-starter for IFR. The other thing was the vertical speed was always all over the place on altitude changes, even though it was set at 500 fpm. IMO the Dynon AP in its present status is not capable of flying a coupled vertical approach. Maybe 5.3 makes that performance better.....

I am in the process of installing an AFS system along with an AFS branded TT DigiFlight II VSVG. I have not yet flown behind a TT AP, but everyone I know that has loves it. My only other AP experience was an analog King KFC200 installed in an A36 Bonanza. That thing was excellent and would hold altitude and heading just about perfectly, plus was excellent on vertical guidance. If the TT comes close to that performance I'll be a happy camper. The downside to the King was its price tag at $50k.

jchang10
04-01-2010, 02:59 PM
Dynon sure seems like they shot themselves in the foot taking on the autopilot.

Bullet 1. All the effort going into the AP probably inevitably has delayed progress on the Skyview. Lack of supported features in Skyview has detracted buyers.

Bullet 2. Not supporting Trutrack AP's alone, have detracted buyers.

Bullet 3. Tying the AP to the EFIS, has detracted buyers.

3 more bullets left.

FrankK90989
04-01-2010, 03:08 PM
Dynon users--- Give 5.3 a try and report back...........:cool::)

Brantel
04-01-2010, 03:15 PM
I think that the AP was way harder than they thought it would be and the Skyview stepped on their ability to give the AP the attention it deserves. The Skyview is gonna need a workable AP to survive so once they hit that point, I have a feeling that you will see some significant AP improvements come along.

My only fear is that Dynon leaves the legacy system as is and does not make the legacy AP better in hopes that legacy users will upgrade. That would be a bad move as it will discourage new buyers of either system.

They had to do the Skyview when they did in order to not get too far behind. As you can see, they are trying to catch up to AFS and GRT now.

Dynon sure seems like they shot themselves in the foot taking on the autopilot.

Bullet 1. All the effort going into the AP probably inevitably has delayed progress on the Skyview. Lack of supported features in Skyview has detracted buyers.

Bullet 2. Not supporting Trutrack AP's alone, have detracted buyers.

Bullet 3. Tying the AP to the EFIS, has detracted buyers.

3 more bullets left.

Radomir
04-01-2010, 03:45 PM
What would you expect of legacy systems? What improvements can they make? I'm not sure they're intentionally forcing an upgrade, but hardware can do only so much before you max it out. Legacy system does what it does well.. but that's about it.

It really looks like they were busy selling legacy systems (in large volumes) at expense of new developments... Would have been OK if competition didn't exist :)

The worst case scenario is to have a whole gamut of products.. none of them doing anything particularly "advanced."

Ironflight
04-01-2010, 04:30 PM
The Skyview is gonna need a workable AP to survive so once they hit that point, I have a feeling that you will see some significant AP improvements come along.


Hmmm....I'm trying to decide if that is a true statement or not. Neither GRT or AFS has their own A/P (nor does the G3X for that matter) - they rely on you bringing your own A/P to the game. Maybe you mean that would give them a competitive edge over the others?

Personally, I am in the camp that believes in keeping the A/P separate from, but controllable through, the EFIS for redundancy purposes for IFR. VFR? All in one isn't a bad proposition if it works!

Paul

flickroll
04-01-2010, 04:47 PM
Personally, I am in the camp that believes in keeping the A/P separate from, but controllable through, the EFIS for redundancy purposes for IFR.

I wholeheartedly agree. In the world of IFR, redundancy is King! Which is another reason why the Dynon system is coming out and the AFS system is going in. There were just too many eggs in one basket for my 'old' Dynon panel to be SAFE for IFR. It was legal, but not particularly safe.

Brantel
04-01-2010, 09:02 PM
The statement is very very true if Dynon continues to stand firm on their stance that they will not produce an EFIS that is capable of driving third party GPSS and GPSV enabled autopilots like GRT, AFS and MGL all do.

If they change that position, yes this is not a valid statement.

I stand by that statement because to get the functionality of the GRT/AFS/MGL - TT combo, the Skyview will need a AP that works.

Sure you can always couple pair up a Skyview with a high end TT and get similar functionality but at a much higher cost and with no integration with the EFIS.......

Oh you bet you can also pair up a Skyview with a low end TT connected to a 296 GPS. But you won't get any EFIS integration, no GPSS/GPSV or any other nifty features that these other units provide.

Hmmm....I'm trying to decide if that is a true statement or not. Neither GRT or AFS has their own A/P (now does the G3X for that matter) - they rely on you bringing your own A/P to the game. Maybe you mean that would give them a competitive edge over the others?

Personally, I am in the camp that believes in keeping the A/P separate from, but controllable through, the EFIS for redundancy purposes for IFR. VFR? All in one isn't a bad proposition if it works!

Paul

Brantel
04-01-2010, 09:06 PM
In a dual EFIS setup, one could argue this point all day with the exception of the similar code issue taking em both out if there is a bug or similar hardware fault at the same time. Anyone ever had this happen?

Personally, I am in the camp that believes in keeping the A/P separate from, but controllable through, the EFIS for redundancy purposes for IFR. VFR? All in one isn't a bad proposition if it works!

Paul

I wholeheartedly agree. In the world of IFR, redundancy is King! Which is another reason why the Dynon system is coming out and the AFS system is going in. There were just too many eggs in one basket for my 'old' Dynon panel to be SAFE for IFR. It was legal, but not particularly safe.

Brantel
04-01-2010, 09:18 PM
I want the legacy system to deliver the features that were marketed at the time I purchased it in a well working manner without bugs or performance issues that render the feature unusable.

They must get the AP working and working well in the legacy system or the future of Dynon is dark. I would expect nothing more from the legacy system as Dynon never comited to anything more. (except the AP76 but forget that, its another story)

Prospective customers of the Skyview are never going to commit to a company that never finishes what they started...Buying a Skyview today is placing a huge amount of faith in Dynon making good on all of the planned features.

What would you expect of legacy systems? What improvements can they make? I'm not sure they're intentionally forcing an upgrade, but hardware can do only so much before you max it out. Legacy system does what it does well.. but that's about it.

It really looks like they were busy selling legacy systems (in large volumes) at expense of new developments... Would have been OK if competition didn't exist :)

The worst case scenario is to have a whole gamut of products.. none of them doing anything particularly "advanced."

Ironflight
04-01-2010, 09:49 PM
I htink we're pretty much onthe same page Brian.

In a dual EFIS setup, one could argue this point all day with the exception of the similar code issue taking em both out if there is a bug or similar hardware fault at the same time. Anyone ever had this happen?

Since you asked - yes....very rare, but yes, I have had a code bug bring down two displays in a two-display system (it was during installation, during a software upgrade). It was on the Dynon I am afraid - legacy systems, several code versions before, no problems since.

And lest anyone thing I am knocking Dynon (the company went overboard in getting it fixed FAST, and we were very pleased), I've also had this happen with extremely expensive multi-computer aerospace systems - inflight. Which is why I like dis-similar redundancy. No design is perfect!

Paul

jeff beckley
04-01-2010, 10:17 PM
I have to brag on Trutrak EFIS. I was once a Blue Mountain sufferer and swore that I would not ever buy another autopilot that was driven by an EFIS until TT came out with there EFIS. The difference is that the EFIS IS the autopilot just as the control head for all there other products are with the exception that the AP controller is graphical. Instead of a few lines of LCD text you get a full HSI, CDI, Horizon, Air Speed, everything to replace standard six pack and much more.
TruTrak has no intentions of adding mapping features for now but that is not the focus of there EFIS. It is designed to allow precise control of your aircraft with integration from most nav radios including the 430w. It fly's IFR approaches and Vnav/LPV and GPS approaches better than any other autopilot I have seen. Even better than the top of the line Stec. I find it is silky smooth in rough air as well as smooth air. Has voice annunciations for every facet of the flight like loss of GPS signal or positive capture of the glide slope or if the LPV approach was downgraded by the 430W or if you are out of trim.
A real safety feature if something changes in your flight or approach if you happen to be looking somewhere else.

The display is bright and laid out in such a way that the data is easy to understand. Very small learning curve.

The design of the software is exceptional with all functions related to any type of approach using only one key press. NO sub menus to thumb through. Every feature you need for the phase of flight you are in at the moment is represented above one of the five buttons. Two knobs on the left and right control heading and altitude respectively.
Performance is stellar! Never has missed Que to capture G/S or wandered off course even a few feet. You can preselect altitude, Control rate of climb or descent by a simple twist of the knob. Holds altitude within 10 feet.
Incredibly simple to use but very intelligent.
It will not let the aircraft stall even in an accelerated climbing turn or low airspeed. One feature is the Level button (I call it the OH S&^T!! Button) A separate button placed any where that when pressed will level and regain control of the aircraft if you happen to get into some trouble. Real nice to simply press if you need to shift focus to get something from the back like a chart or puke bag.
It is designed to be the best autopilot you can buy. If you need mapping then add a 496 or 560. The EFIS IS THE AUTOPILOT CONTROLLER, not just a Geewhizzbang display that just happens to give limited control over a set of servos while struggling to decode data from a WASS receiver.

I regularly fly IFR down to minimums with this display. I completely trust it.
BUT!! I also have backup AS,ALT,and a Trutrak ADI with battery backup that displays additional Horizon,GPS Heading,Turn slip/ball just in case the display goes bad. Any EFIS can go t*ts up and without backups you better not venture into IFR regardless if the display is tied into the AP or not.
Dynon has a nice display but it is not ready for prime time AP control. They are also a good strong company that will be around for a long time. They are less expensive but the AP features are also not there. Maybe after they get the SkyView fully launched they will focus on the AP but even then it will take a while.
TruTrak is fully mature. All of the features are fully active. I am not waiting for any more updates to make it more usable or stable. Well maybe a auto land feature:D

rvmills
04-01-2010, 11:00 PM
I'm hoping Brian is right, and Dynon continues to deliver improvements to their AP. Hopefully it will be not only because the SkyView needs a top-notch AP to be competetive with other upper-tier glass products (think Syntetic Vision, etc.) but also because legacy product users (like me) want all the features and performance of stand alone standouts like TT and Trio. If Skyview pulls the AP development along, then its for the betterment of all Dynon AP users...so I do hope Brian is correct!

For Weasel, I have a Dynon AP (D100, D10A, AP-74, SV-32 x2) in my 6, and have flown a fair bit in my friend's 9A with a TT DFII-VSG. We talked about this thread today, and compared capabilities, and I looked again at the TT site to double check. I'd give his TT VSG the edge in performance and smoothness, and mine the edge in features and capabilities (at least for the way I like to fly the AP, which can vary from pilot to pilot, so its a bit of opinion). Here's some thoughts for your research...not gospel, just one user's thoughts:

In performance, his TT is rock solid in pitch and roll...its really a nice ride. Comparing his 9A to my clipped wing Super 6 may be a bit unfair, but his ride is better, and is what I'm looking for. I'm getting close, but did have some pitch oscillations early-on, which have been mostly mitigated by doing the pitch servo shear screw service, and playing with the settings. I now have solid altitude hold except in bumps, which I can ease with setting control. Still an occasional oscillation, and not quite as smooth as the 9A/TT, but getting better.

In roll, I had better performance in NAV than in HDG, but a few compass cals helped that immensly, as did playing with the settings. I had the "NAV Source Lost" issue that appears to have been fixed with FW updates (big X-C next week to see...and will see if 5.3 shows more improvements...putting that in this week). Dan's 9A/TT is more solid in heading than mine, but I'm starting to approach it.

One area where the Dynon shines (IMHO) with the ability to pre-select altitude settings. My AP will climb/descend to the preset alt at (well close to) the configured VSI and level off. Dan's VSG will not do that. He has to level off and engage ALT hold. A VSGV may or may not level off at a preset alt, but I can't tell from the website (don't want to put out bad gouge...someone else will know for sure).

However, Dan can climb/descend at a particular VSI, and can adjust the rate of climb/descent right on the control head, which I cannot do. I have to go into a menu on the EFIS, and hope that Dynon will add that capability to the AP-74 value knob. An earlier poster mentioned the varied VSI he saw in climbs/descents, and I see that as well. I asked Dynon about that, and the response was somewhat cryptic, in that the instantaneous rate may be being adjusted throughout the descent to give a final average rate of the selected value ie, 500 fpm selected = 4 minutes to descend 2,000 feet, and the VSI is adjusted to meet that target. Just not sure how they do it, but mine does hit time to climb/descend targets, as measured in flight.

The AP-74 is a slick control head, and may give a few more selectable items to the pilot (preset HDG & ALT, Altimeter...I just want to add VSI!). The TT control head has a nice moving out of trim indicator, perhaps better than the Dynon's "UP/DN" flags...but the Dynon indicator is on the EFIS, where one's scan is focused more often, so that may be a wash.

The VSGV has GPSS and GPSV, while the VSG has only GPSS. The Dynon AP has GPSS, but won't have the GPSV until the AP-76 is a reality (or they change something else) at least that's the way I understand it. Therefore, I feel my Dynon AP's feature set falls between the VSG and the VSGV. TT has a few things I covet, and my Dynon has some things I'm very happy with, as described above.

When doing my panel upgrade I was going to add a TT and a backup airspeed indicator to my D100 panel, but when Dynon annouced it's AP, I realized I could get a second EFIS (for all the backup instruments), two servos and an AP-74 for less than a TT VSG, so I went that way. Granted, I have a VFR panel (VFR GPS and no VOR/ILS), so the separate manufacturer redundency was less critical to me...though I certainly respect it as an IFR pilot. If you're building an IFR machine, that may be a more important factor, and GPSV and coupled approaches may be as well. I hope the Dynon AP gets there. I'm happy with it on my airplane, in my VFR mission. In my case more equipment and features (extra EFIS and the AP) for less $$ has worked well. All the bells and whistles and cost savings in the world aren't worth it if it won't work in your aircraft...but Dynon has been very proactive in fixes and updates. Just wanted to give you some feedback to apply towards your plane/misson, and hope it helps. Have fun putting it together, whichever way you go!

Cheers,
Bob

flickroll
04-02-2010, 08:35 AM
In a dual EFIS setup, one could argue this point all day with the exception of the similar code issue taking em both out if there is a bug or similar hardware fault at the same time. Anyone ever had this happen?

That has never happened to me but it can and does happen. Dynon had an issue with their 5.2 release when both a 100 and a 180 were in the same setup. AFS recently had a mandatory service bulletin over a software bug. So redundancy does not necessarily mean 2 independent EFIS units from the same manufacturer. I will have redundant AFS EFIS units (with battery backup) in my new installation, but will also have a TT AP which by itself can keep the blue side up, plus a 696 whose GPS derived 6 pack will also allow you to keep the blue side up. The 696 also has an internal battery, and I'll feel pretty safe with this panel.

Wesael
04-02-2010, 12:32 PM
I really appreciate all the information that yall have put forth.

I currently fly behind a Trio and have flown quite a few different airplanes with TT.

However I have never flown behind Dynon's AP.

Now after reading this tread I feel like I have.:p :p

Thanks to all!

wjnmd
04-02-2010, 01:27 PM
These have been some very good thought provoking posts. I was thinking about putting in the Trutrak EFIS/Autopilot and EMS for my panel upgrade but if it is better to have the autopilot as a separate unit then I could look into a Dynon or AFS EFIS and EMS. Both of those appear to be excellent units but I hear uniformly good things about the Trutrak autopilot. My question is whether or not the Trutrak ADI Pilot II complies with the required gyro attitude indicator and gyro heading indicator for instrument flight since it is also an autopilot. Since I am a pay-as-you-go type builder,this would allow an upgrade to the ADI Pilot II and then put in the EFIS and EMS later. I appreciate any thoughts or critiques of my logic.

Bill Near
RV-7A flying

RONSIM
04-02-2010, 02:04 PM
Bill, we have the ADI II in both our RV-8A and RV-10 at KCLW -- GREAT units and do a good job. However, for IFR attitude and heading info, the information provided by the ADI II is too limited. the attitude picture is very limited in roll and pitch, and the "track" info is GPS derived. I would recommend having a "real" AI and HI, in some other format for IFR work, using the ADI II as "backup". Again, as an autopilot, the TT works really well.

Frank Smidler
04-02-2010, 09:32 PM
I see that TruTrak has a new, lower cost EFIS system announced in a full page ad in the new (April) Sports Aviation. The $2200 price mentioned is considerable less than the SG base $3800. What the ad did not tell is what is different with this unit. I went to their web site and the GP was not even mentioned. Does anyone know anything about this unit? Is it the same size as the SG? What functionality was lost?

TrutrakTech
04-03-2010, 03:27 AM
I see that TruTrak has a new, lower cost EFIS system announced in a full page ad in the new (April) Sports Aviation. The $2200 price mentioned is considerable less than the SG base $3800. What the ad did not tell is what is different with this unit. I went to their web site and the GP was not even mentioned. Does anyone know anything about this unit? Is it the same size as the SG? What functionality was lost?

Our revamped website should be up within the week and we'll have more info at Sun n Fun as well. There are some other things to see as well, sonic you're at Sun n Fun, definitely make a point to stop by!