TruTrac

TruTrac introduced a new AutoPilot at Osh. $1000 , does that include the servos ? I can't imagine it does . The Webb Site is rather vague .

It does.

I looked at this thing at OSH. It's pretty slick. The ECO uses R/C servos to move a fairly good sized trim tab attached to an aileron and the elevator. I'd estimate it's about an inch or so by six inches. The servo mounts inside the control surface and moves the tab, the tab "flies" the control surface. My understanding is that the whole assembly comes as a unit, you cut a hole and screw or pop rivet it in place. Really nice setup, I had some real reservations about it until I saw it. Someone was using their noggin.

But yeah, their web guys aren't quite as up to speed as their autopilot guys, that's for sure.

I looked at this thing too. I guess the best thing I can say about it is you get what you pay for. TruTrac being a really good company, I can't say anything bad about this product but I do have to say that I have been flying RC planes for a very long time. Seen just about all of the different brand servos and they all fail at some point. It may not be a complete failure but they lose accuracy with use, metal gears strip (forget plastic gears), etc.
I'm sure this product can be used to ease cross country VFR flying and help with pilot workload, but I would have a hard time putting my life on the line with these small servos during an IFR flight.
YMMV
Take it for what's it worth = $0.00

Yeah, I thought about the longevity of the servos... but you could replace both of them annually and not even feel the hit to your wallet. I don't think they're targeting the upper end of the market (heavy duty IFR flying) with this, though.

DaleB said:

It does.

I looked at this thing at OSH. It's pretty slick. The ECO uses R/C servos to move a fairly good sized trim tab attached to an aileron and the elevator. I'd estimate it's about an inch or so by six inches. The servo mounts inside the control surface and moves the tab, the tab "flies" the control surface. My understanding is that the whole assembly comes as a unit, you cut a hole and screw or pop rivet it in place. Really nice setup, I had some real reservations about it until I saw it. Someone was using their noggin.

But yeah, their web guys aren't quite as up to speed as their autopilot guys, that's for sure.

Click to expand...

We're our own web guys. We'll put more information on the website as we get closer to release. We're still working on some things regarding tabs, installation, software, etc. What we've found in the past is if we put too much information on the site too soon, customers get an impression that it's available now. We don't want to give everyone that idea when we're still 1.5 months from release. If you'd like some more info, please feel free to ask, pm, email, whatever!

BCP Boys said:

I looked at this thing too. I guess the best thing I can say about it is you get what you pay for. TruTrac being a really good company, I can't say anything bad about this product but I do have to say that I have been flying RC planes for a very long time. Seen just about all of the different brand servos and they all fail at some point. It may not be a complete failure but they lose accuracy with use, metal gears strip (forget plastic gears), etc.
I'm sure this product can be used to ease cross country VFR flying and help with pilot workload, but I would have a hard time putting my life on the line with these small servos during an IFR flight.
YMMV
Take it for what's it worth = $0.00

Click to expand...

Two things. The Eco is an extremely basic autopilot. No altitude select, no selectable track/heading. It simply holds what you're doing or tracks to a waypoint. Its intent is not for IFR/IMC flight. Secondly, the servos will have a TBO limit on them. So we've got that covered. Also, a failure of one of these servos is really a non-event. Even a hardover failure and all you have is an airplane that is out of trim. I'd venture a guess we can all handle that.

DaleB said:

Yeah, I thought about the longevity of the servos... but you could replace both of them annually and not even feel the hit to your wallet. I don't think they're targeting the upper end of the market (heavy duty IFR flying) with this, though.

Click to expand...

Bingo! We've got the "upper" end of the market covered with our other products. We're filling a void in the market with Eco.

I would imagine that the traditional RV's are not the primary target market for this product.

RV's have such a huge speed range that one needs to seriously consider the impact this type of system can have on the flutter characteristics of the airplane's control surfaces not only in the normal mode but also in all the possible failure modes across the full range of the flight envelope.

I am sure the team at TT can discuss this in detail with you if you are considering this system. It would be a wise thing to discuss with them.

AEP video

Here's a little video of some testing of the envelope protection mode on the Eco that we did yesterday. Our limiter was set to 30 degrees of bank.

https://www.youtube.com/watch?v=UXiOdDFlxaM

safety question

As chief pilot for a company developing an autopilot that drove the trim tabs, I asked the question: "What loads are acceptable on the controls in cruise flight if a trim tab runs to full deflection?" I never received a straight answer.
I would like to see a video posted of the same red plane flying at cruise speed with that small tab deflected to the limit. I'm not being a smart alleck, I really have no idea what forces will be generated in the scenario.
I did have one of the engineers run the elevator trim all the way down before takeoff doing a software upgrade. I missed it on my checklist and attempted to depart. Had to abort do to excessive forces on the controls. It was a heavier plane than an RV, so the comparison may not be valid.
Since you are in the development phase before release for sale, can you test this and report back? Thanks in advance for your consideration.

flightlogic said:

As chief pilot for a company developing an autopilot that drove the trim tabs, I asked the question: "What loads are acceptable on the controls in cruise flight if a trim tab runs to full deflection?" I never received a straight answer.
I would like to see a video posted of the same red plane flying at cruise speed with that small tab deflected to the limit. I'm not being a smart alleck, I really have no idea what forces will be generated in the scenario.
I did have one of the engineers run the elevator trim all the way down before takeoff doing a software upgrade. I missed it on my checklist and attempted to depart. Had to abort do to excessive forces on the controls. It was a heavier plane than an RV, so the comparison may not be valid.
Since you are in the development phase before release for sale, can you test this and report back? Thanks in advance for your consideration.

Click to expand...

I can assure you, all of these will be tested. The red airplane in the video is the Trutrak RV10. I, personally, have flown it with the tabs deflected to a mechanical stop and, while stiff (of course), it is controllable, even the elevator.

Thanks for the quick reply Lucas. I appreciate the data, and so will others.
One of the simple things that builders overlook is the fact that the trim tab is "out of the pilot's control" if the servo or driver circuits run it to the limit.
The deflection, and resultant forces will be carried all the way through landing...
Older, mechanical designs that had cables driving the tabs, could be re-trimmed after pulling a breaker.
I asked the FAA engineers once what the acceptable number of pounds of force on an elevator control are allowed with a trim at full deflection. (This was asked with an illustration of a smaller pilot or woman flying.) They could not answer the question. Think 50 pound bag of cement in your hands during a higher speed descent for example. Anyway, I am interested to watch the development process. Thanks again for the reply.

TrutrakTech said:

it is controllable, even the elevator.

Click to expand...

I think that the answer is, it depends......

I had a situation in which my elevator trim was in the full up mode on my RV-10 during take off. It was darn impossible to get the nose down with the stick until I realized what the problem was and corrected it. I was very thankful that day that I had installed an AOA.

Lesson Learned: visually validate on preflight, since the Ray Allen sensor gave an incorrect value, then I corrected it inappropriately per the sensor reading.

rleffler said:

I think that the answer is, it depends......

I had a situation in which my elevator trim was in the full up mode on my RV-10 during take off. It was darn impossible to get the nose down with the stick until I realized what the problem was and corrected it. I was very thankful that day that I had installed an AOA.

Lesson Learned: visually validate on preflight, since the Ray Allen sensor gave an incorrect value, then I corrected it inappropriately per the sensor reading.

Click to expand...

That's true. But the RV10 trim tab is HUGE. The Eco tab is only a fraction of the size of the trim tab on an RV10. We're not planning to use a single tab for every installation. That just won't work, so different aircraft will have different sized tabs.