# Another affordable avionic - iLevil AP

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#### Rhino

##### Well-Known Member
I think he big question is perhaps whether this autopilot that works only on the secondary surfaces if it really works or can put the plane in a PIO-type oscillation?...
People are using them without reporting such problems, so the obvious answer is yes, they work without creating PIOs.

...I hadn't even thought about this issue of interference, but it makes sense since a device that depends on wifi on board can both promote and suffer interference...
You brought up the interference issue, so obviously you've thought about it. You could be extremely limited if you operate based on the premise that wifi is an interference danger. Wifi is used extensively in aircraft cockpit systems, even by the big, brand name manufacturers. It's used extensively by portable devices such as ADS-B receivers, and by commonly used aviation apps such as Foreflight. Is it possible that wifi could cause or be disrupted by interference? Yes, it's possible. It's also possible for that to happen to just about anything else in my cockpit that uses or relies on RF radiation, but I'm not going to stop using my radios just because it's possible they could be interfered with, or cause interference. As for the video you linked, I saw nothing that indicated wifi had anything to do with his problem. So again, if you have concrete information pointing to wifi as an inherent cause of harmful interference in the cockpit, we'd like to hear about it. That's something important we'd like to be aware of. But without any such information, all you have is a suspicion unsupported by fact.

We all take risks, and we all mitigate them to the maximum extent possible based on our circumstances. As I said earlier, any impact such a problem might cause will be highly dependent on the circumstances of the individual pilot, and that pilots' mitigation efforts should be prioritized accordingly. If you're flying circumstances make an autopilot an absolutely critical system with absolute minimum margin for failure, you're going to be far more selective than other pilots without those same circumstances. But if you're going to be highly selective in that regard, it's also somewhat axiomatic that such a high standard is going to limit you to the more expensive systems. It's somewhat unrealistic to expect that the most capable and hardened systems are going to cost as little or less than those that don't seem to meet that same criteria. You get what you pay for in most circumstances, and you probably shouldn't be expecting otherwise. Now as far as wishing goes, brother, we're all in the same boat. I can wish with the absolute best of them. Just ask my wife.

#### PatrickW

##### Active Member
First thing to come to mind was the weight savings.

I've got a brand new Dynon SV42 servo on my desk right now, for my next project. It's very heavy (and it's just one of two).

This trim-tab actuated system looks MUCH lighter. I have no idea how it performs in the air, however. If performance is equivalent, it could be a game-changer...

- Pat

#### Rhino

##### Well-Known Member
I guess perceptions are relative. Three pounds isn't all that heavy for an autopilot servo. It's lighter than the TruTrak servos it was designed to replace. Sure, I'd rather save the pounds if I could, but that's true for anything I put on my plane. So to me it's no different than anything else. It's an additional capability that has additional weight. Nothing new. I don't have the options you do though. There is no aileron trim tab on a Zenith CH 750 STOL, unless I design and add one myself. But that would add weight.

#### rv7charlie

##### Well-Known Member
There are no aileron tabs on an RV, nor on the T-18 I owned. On the T-18, the added tab served as both roll trim and autopilot servo. My current RV-6 has an added roll trim tab, driven by a common MAC trim servo. (Van's recommended trim system is a pair of bias springs connected to the 'walking beam' that the sticks control.)

#### SheepdogRD

##### Active Member
HBA Supporter
I haven't done any programming for decades, so the do-it-myself autopilot systems don't hold much appeal for me. I've put in my order for the Levil AP (https://www.homebuiltairplanes.com/forums/threads/another-affordable-avionic-ilevil-ap).

It appears to be an outgrowth of work the company did with TruTrak on the "ECO" autopilot. TruTrak, which became part of Bendix-King in 2019, stopped their development program, but Levil continued theirs.

The Levil AP unit is similar to their Levil 3AW, but it adds the AutoPilot function. All of the information can be displayed -- via Wi-Fi -- on relatively inexpensive iPads or iPhones, and the Levil app for that is free. The Levil AP with an iPad produces a glass panel and a 2-axis autopilot for about $3K total. An additional display (iPad or iPhone) is relatively inexpensive; I'll be using two iPad Mini4 units. The system is light in both cost and weight. The Levil AP unit weighs 11 ounces. The trim units -- including tabs and actuator -- weigh 5.3 ounces each. The installed AP system weighs well under 2 pounds. If you're only interested in a 2-axis autopilot, Levil's sister company, Aircraft Automation, offers the same trim tab autopilot with an HSI for$2700 at Aircraft Automation – Trim Tab Autopilot. All the components are available individually if you want to build your own.

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#### Rhino

##### Well-Known Member
If you want to get reeeeeally simple...

#### pfarber

##### Well-Known Member
Keep in mind the <price< difference from a Garmin and other <supposed, cheap stuff. Is bad electronic, bad developpement and no noise testing or proper electronic test and no regulation test. Don<t complain about radio interference and so on. A 3.5 / 5 in sunreadable is 400$alone. The cpu cheap microcontroller are like arduino for 8$ and the main part, as the requirement : the sensor : is only a cheap one at 2$, not even a backup or something else. The gx5 from Garmin do have the autopilot included , fully test and working. But at same time people want to safe 50cent on bolt. Safety in flight should not be rule by : hey i save 400$ for something that is not tested, don<t do even the quarter of a real system. No gain here. Doing pcb and circuit help to see that more easily.
You really shouldn't get on your knees for Garmin. Some of their gear is hot garbage and stopping the 430 to 430W upgrades was a pure money grab.

Also, the NTSB has quite a few IFR incidents with G5s rebooting or giving an AHRS alignment error... in actual IMC.

So yeah, tell Garmin to fix their sh t

#### edwisch

##### Well-Known Member
You really shouldn't get on your knees for Garmin. Some of their gear is hot garbage and stopping the 430 to 430W upgrades was a pure money grab.

Also, the NTSB has quite a few IFR incidents with G5s rebooting or giving an AHRS alignment error... in actual IMC.

So yeah, tell Garmin to fix their sh t
Is there any reason to take your comments seriously? Sounds like you just need to vent and you hate Garmin. Other avionics vendors at all levels have had similar kinds of issues.

BJC

#### Mark Z

##### Well-Known Member
I love autopilots but I fear many pilots that grew up in the century of the glass cockpit and magenta line have become autopilot cripples. Why babysit an autopilot when I trust myself to comfortably hand fly that approach to landing or missed?

#### rv7charlie

##### Well-Known Member
I seriously doubt that particular a/p will fly an approach anyway, so the point seems moot.
Flying an RV, Thorp, Mustang II on a 2 or 3 hr cross country can make you really grateful for at least a wing leveler. More or less the equivalent of having cruise control in a car. I find I can be much more aware of traffic around me, and I arrive much more rested; not being fatigued at the end of a flight can be a significant safety factor.

Now becoming navigation cripples; that's a different matter. And if subjected to torture, I'd probably have to admit that my VFR flight planning has degenerated to 'how long, with prevailing winds' and will I land with plenty of fuel.

#### Mark Z

##### Well-Known Member
For the last 5 years I’ve flown up to Oshkosh in an RV6 from Texas. We trade off every hour wishing we did have an autopilot. It’s really a must if you’re flying a high performance airplane.

#### TiPi

##### Well-Known Member
HBA Supporter
Log Member
One thing to consider when using an iPad (or any other tablet) is that they are heat-sensitive. I had my iPad shut down a number of times because it was exposed to some sunlight. I always keep my phone handy in a shady spot with the nav app activated. Dedicated (aviation) displays have a much higher heat tolerance.

#### rv7charlie

##### Well-Known Member
Ipads are notorious for that. My Android stuff has been much more rugged, and a lot less expensive.

#### SheepdogRD

##### Active Member
HBA Supporter
My dual-iPad Mini installation has the screens mounted in front of the panel in RAM EZ-Roll’r cradles. PC-type pancake fans blow air onto the backs of the iPads. They're shaded by the glareshield, and the sunroof is tinted with UV-protectant film. The system isn't flight-tested, yet, but the experience of others with these mounts lends some confidence that they'll function reliably, even here in the south.

BJC

#### edwisch

##### Well-Known Member
I seriously doubt that particular a/p will fly an approach anyway, so the point seems moot.
I recently did a 90 minute X-C in the RV-9A with Garmin G3X Touch, autopilot on from after takeoff to minimums. All I touched was power and flaps. The capabilities these days are astounding!!

#### rv7charlie

##### Well-Known Member
Some of the almost-20-year-old TruTraks will do that as well, but not the more basic versions.