Jamie
Well Known Member
First of all, a disclaimer: The purpose of this writing is not to bash any autopilot manufacturer, but rather to share my personal experiences with my fellow builders and dreamers. Each vendor I have dealt with has been unquestionably committed to helping me with my issues and have gone above and beyond to make me a satisfied customer.
When I first flew my airplane on 7/28/2007 it had a Trio Ez-Pilot installed. I had flown in a couple of other airplanes with the EzPilot installed (Mike Stewart's old -6A and his new Super 8) and I was very impressed with the performance. I was generally impressed with the smoothness and the PLED display which showed data from the NMEA stream (very handy).
However, I could never get the Ez Pilot to work right in my -7A, no matter what I tried. [Thread is here] I isolated everything electrically. The EzPilot would rock the wings. I tried every setting. I talked to the Trio guys quite a bit and although helpful, we were never able to come to a conclusion to the issue. I ended up hand-flying the airplane to and from OSH, Pennsylvania, VA, etc. Don't get me wrong, the airplane trims beautifully and I had no problems hand flying it, but an autopilot would have been nice to give the PIC a little break from maintaining heading and especially altitude.
Next I saw an advertisement for Dynon's new autopilot on vansairforce.net. Ok, that was the ticket for me! Only $1500.00 for a two-axis autopilot (I already had a D10-A). The autopilot install was fairly straight-forward, it just required a lot of work (mostly pulling wires).
I was very disappointed that I was never able to get the Dynon to work quite right. [Thread on this issue here] For me it would have been an ideal solution. The AP would hold altitude, but not smoothly. You could always "feel" the autopilot agressively trying to maintain altitude and even then it would deviate by sometimes 30 feet, then hunt sporadically around the target several times until it finally got close again.
The AP would hold a course or heading, but the slightest attitude disturbance in turbulance would rock the wings two or three times. To this day I have not flown in another airplane with the Dynon AP. I did talk to three or four other Dynon AP customers that reported that their APs worked fine, so I am still at a loss to understand exactly what was happening here. Maybe I just have a sensitive rear?
Let me make this abundantly clear. Dynon stands behind their products. They refunded my money, even after asking me if I wanted to take a full refund, keep the servos and become a member of their beta program! That was indeed a tempting offer, but with a 16 month old son at home I simply didn't have the time to do it. My flying is sometimes rare and is therefore very cherished. Consequently, I just want everything in the airplane to work with no squawks whatsoever. If there is a squawk it will just annoy me to no end.
This basically left me with just one other AP vendor that caters to experimentals -- Trutrak.
I spoke with Lucas at Trutrak and explained to him my situation with trying other APs and having issues. He made me an incredible offer. He said they guaranteed their AP to work in my airplane and they would ship me any of their units at no charge to try it (I think they were taking pity on me at this point). If I liked their unit, I could pay them for it. If not, I could just return it.
Ok, so how do you pass up a deal like that? I actually hesitated on the offer for a couple of weeks but then decided with the upcoming summer trips my wife and I have planned (NY, etc) it would be a good time to try it. I called Lucas back up and he asked me which one I wanted. I asked for the Digiflight II, because basically that's the functionality that I wanted. I don't really care for VS select or GPSS. I may one day, and upgrading later will be rather easy.
I received the unit and calibrated it per the installation instructions. My first impression with the Trutrak was that there are a *lot* of configuration settings to allow you to tweak the AP performance to your likes and to your particular airplane. I thought to myself that if the Trutrak wouldn't fly my airplane well that I would just have to give up on the search for an AP.
I made the first flight with the AP, climbed to 10,500 and started testing and doing in-flight adjustments. First I simply tried the roll axis. Perfect. Next, pitch. It was oscillating a little bit. I tried combinations of tweaking the "activity level", "microactivity" and "static lag" settings. I ended up using a static lag setting of 1, a microactivity setting of 1 and leaving the activity level to a setting of 2 (what is called for in the calibration settings). It seemed like I had it dialed in but the true test would only come with a long trip.
Saturday, April 4th we had planned a trip to North Carolina to see some friends. This trip would take us from our homebase (LZU) near Atlanta to just east of Raleigh, NC (LHZ - Franklin County). Going around the Charlotte class B made this trip 317nm. I took off and at 1000ft AGL I engaged the roll axis and trimmed for my desired climb. After leveling off and trimming at 9500 in the smooth air that is so typical of an 0630 launch, I engaged the altitude hold.
Performance? Absolutely Perfect. The flight up was 1.8 hours. The AP never once deviated from altitude. Even when moving my legs around, putting my right arm around my wife's shoulders, etc it never moved. My GX-50 is driving the Trutrak and will display course error to the thousandths place. The most deviation I ever saw was 0.002nm. That's about 12 feet!
This is what I saw on most of the trip. The 0.000 is the distance from the course centerline.
On the way back weathermeister.com was telling me to expect some rather fierce headwinds. I climbed up and the winds aloft forcasts were actually pretty good. My EFIS was showing a 50kt wind, 5 degrees off the nose. Great. It was very smooth up there. Ok, so we stay there at near-Skyhawk speeds or we descend down into the bumps and accelerate to Skylane speeds. We descended to 6500 and put up with the bumps (mostly light chop). The flight back was 2.2 hours and I had the AP on all the way. It handled turbulance perfectly! It corrects the way any pilot would correct -- better even.
The entire flight was made much more relaxing with the autopilot. I never once felt like it was going to do something unexpected, even in turbulence.
I obviously called Lucas and paid for the Trutrak.
I am very happy with this AP. Why did I have so much trouble with the others? Perhaps it will always be a lingering question in the back of my mind. I can only speculate, but I think it may have something to do with the abundance of settings available on the Trutrak. The Dynon really only has two settings; Torque and Sensitivity (which is akin to the Activity Level on the Trutrak or "Gain" on other APs). The trick to *really* smoothing out my AP's performance was the static lag. When I increased that setting from 0 to 1 the pitch performance noticeably smoothed out. Increasing the microactivity setting was just icing on the cake for a near-perfect ride.
And when I say near-perfect...I mean that. The Digiflight II flies the airplane very, very well.
Some more pics from our flight up and back:
Sunrise after 0630 launch.
A blurry shot (taken in low light) of the panel and the DII over on the right (replaced a whiskey compass).
When I first flew my airplane on 7/28/2007 it had a Trio Ez-Pilot installed. I had flown in a couple of other airplanes with the EzPilot installed (Mike Stewart's old -6A and his new Super 8) and I was very impressed with the performance. I was generally impressed with the smoothness and the PLED display which showed data from the NMEA stream (very handy).
However, I could never get the Ez Pilot to work right in my -7A, no matter what I tried. [Thread is here] I isolated everything electrically. The EzPilot would rock the wings. I tried every setting. I talked to the Trio guys quite a bit and although helpful, we were never able to come to a conclusion to the issue. I ended up hand-flying the airplane to and from OSH, Pennsylvania, VA, etc. Don't get me wrong, the airplane trims beautifully and I had no problems hand flying it, but an autopilot would have been nice to give the PIC a little break from maintaining heading and especially altitude.
Next I saw an advertisement for Dynon's new autopilot on vansairforce.net. Ok, that was the ticket for me! Only $1500.00 for a two-axis autopilot (I already had a D10-A). The autopilot install was fairly straight-forward, it just required a lot of work (mostly pulling wires).
I was very disappointed that I was never able to get the Dynon to work quite right. [Thread on this issue here] For me it would have been an ideal solution. The AP would hold altitude, but not smoothly. You could always "feel" the autopilot agressively trying to maintain altitude and even then it would deviate by sometimes 30 feet, then hunt sporadically around the target several times until it finally got close again.
The AP would hold a course or heading, but the slightest attitude disturbance in turbulance would rock the wings two or three times. To this day I have not flown in another airplane with the Dynon AP. I did talk to three or four other Dynon AP customers that reported that their APs worked fine, so I am still at a loss to understand exactly what was happening here. Maybe I just have a sensitive rear?
Let me make this abundantly clear. Dynon stands behind their products. They refunded my money, even after asking me if I wanted to take a full refund, keep the servos and become a member of their beta program! That was indeed a tempting offer, but with a 16 month old son at home I simply didn't have the time to do it. My flying is sometimes rare and is therefore very cherished. Consequently, I just want everything in the airplane to work with no squawks whatsoever. If there is a squawk it will just annoy me to no end.
This basically left me with just one other AP vendor that caters to experimentals -- Trutrak.
I spoke with Lucas at Trutrak and explained to him my situation with trying other APs and having issues. He made me an incredible offer. He said they guaranteed their AP to work in my airplane and they would ship me any of their units at no charge to try it (I think they were taking pity on me at this point). If I liked their unit, I could pay them for it. If not, I could just return it.
Ok, so how do you pass up a deal like that? I actually hesitated on the offer for a couple of weeks but then decided with the upcoming summer trips my wife and I have planned (NY, etc) it would be a good time to try it. I called Lucas back up and he asked me which one I wanted. I asked for the Digiflight II, because basically that's the functionality that I wanted. I don't really care for VS select or GPSS. I may one day, and upgrading later will be rather easy.
I received the unit and calibrated it per the installation instructions. My first impression with the Trutrak was that there are a *lot* of configuration settings to allow you to tweak the AP performance to your likes and to your particular airplane. I thought to myself that if the Trutrak wouldn't fly my airplane well that I would just have to give up on the search for an AP.
I made the first flight with the AP, climbed to 10,500 and started testing and doing in-flight adjustments. First I simply tried the roll axis. Perfect. Next, pitch. It was oscillating a little bit. I tried combinations of tweaking the "activity level", "microactivity" and "static lag" settings. I ended up using a static lag setting of 1, a microactivity setting of 1 and leaving the activity level to a setting of 2 (what is called for in the calibration settings). It seemed like I had it dialed in but the true test would only come with a long trip.
Saturday, April 4th we had planned a trip to North Carolina to see some friends. This trip would take us from our homebase (LZU) near Atlanta to just east of Raleigh, NC (LHZ - Franklin County). Going around the Charlotte class B made this trip 317nm. I took off and at 1000ft AGL I engaged the roll axis and trimmed for my desired climb. After leveling off and trimming at 9500 in the smooth air that is so typical of an 0630 launch, I engaged the altitude hold.
Performance? Absolutely Perfect. The flight up was 1.8 hours. The AP never once deviated from altitude. Even when moving my legs around, putting my right arm around my wife's shoulders, etc it never moved. My GX-50 is driving the Trutrak and will display course error to the thousandths place. The most deviation I ever saw was 0.002nm. That's about 12 feet!
This is what I saw on most of the trip. The 0.000 is the distance from the course centerline.
On the way back weathermeister.com was telling me to expect some rather fierce headwinds. I climbed up and the winds aloft forcasts were actually pretty good. My EFIS was showing a 50kt wind, 5 degrees off the nose. Great. It was very smooth up there. Ok, so we stay there at near-Skyhawk speeds or we descend down into the bumps and accelerate to Skylane speeds. We descended to 6500 and put up with the bumps (mostly light chop). The flight back was 2.2 hours and I had the AP on all the way. It handled turbulance perfectly! It corrects the way any pilot would correct -- better even.
The entire flight was made much more relaxing with the autopilot. I never once felt like it was going to do something unexpected, even in turbulence.
I obviously called Lucas and paid for the Trutrak.
I am very happy with this AP. Why did I have so much trouble with the others? Perhaps it will always be a lingering question in the back of my mind. I can only speculate, but I think it may have something to do with the abundance of settings available on the Trutrak. The Dynon really only has two settings; Torque and Sensitivity (which is akin to the Activity Level on the Trutrak or "Gain" on other APs). The trick to *really* smoothing out my AP's performance was the static lag. When I increased that setting from 0 to 1 the pitch performance noticeably smoothed out. Increasing the microactivity setting was just icing on the cake for a near-perfect ride.
And when I say near-perfect...I mean that. The Digiflight II flies the airplane very, very well.
Some more pics from our flight up and back:
Sunrise after 0630 launch.
A blurry shot (taken in low light) of the panel and the DII over on the right (replaced a whiskey compass).
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And like ya said, what great customer service from all sides! No doubt due to your extraordinary patience and great attitude!! Happy Flying!
