Autopilot advice

[Tim213]

I'm interested in everyone's opinions and experience with autopilots on the Bearhawk, specifically the 4 place. Do they work or are the controls two heavy?
my only experience is with my RV7 and my Dynon works great, so I'd like to put one in my BH if folks have had good experiences with them. I am going with the RAC electric elevator trim which will indicate off my Dynon EFIS, so I hope to use their autopilot as well. Thanks for any input.

[JimParker256]

I keep wondering the same thing, especially since there is a lot of adverse yaw with all the Bearhawks. I really only want a wing-leveler that would follow a GPS course for longer flights, or when I need to check charts, etc. while single-pilot. But in my head, I'm imagining the autopilot trying to raise a wing, and the aircraft yawing instead of banking... 'Cause that's what happens in the Citabria if you don't lead with rudder.

I saw that Dynon recently released the "yaw damper" software module for their systems, and wondered if it would solve that problem. Meanwhile, I'm watching and observing, trying to learn from others who are WAY ahead of me.

[tailwind]

I have the Garmin system with 2 axis. The system does work and has plenty of power to drive the controls. I ounce hit the button on take off and you can definitely feel the servos working. It is easy to over power them so there is very little hazard when activated. I have a little re-rigging to do in so my unit seeks more than some aircraft that I have flown. It will track to a location nicely even when the air is turbulent. It has been a great aid on long trips. Note: I purchased the high torque servos.

[22LD]

Bob, I have the Garmin GSA 28 servos for my 4 place. Have not installed yet. I was not aware of a "high torque" version and am not seeing that on the Garmin site. Wondering now if I'm going to have to swap these out. I hope not because they've been on the shelf a couple years and they probably will not let me exchange them.

[Bdflies]

Not a 4 place, but I have a Garmin G3X Touch in my Patrol, with pitch and roll servos. Granted, I don't have much experience with it, but I absolutely love it! I have the gain (Garmin's term for speed, or aggressiveness of the servos) fairly low, so adverse yaw is not an issue. It handles turbulence very well. Garmin, too, offers the ability to install a 3rd axis yaw servo, but I haven't seen the need for it. Looking back, I could have bought cheaper seats, or installed the fixed pitch prop, instead of the constant speed system. I'd have enjoyed the plane just as much. But those servos have to be the best money spent! I'll be learning the system's capabilities for a while!


Bill

[jaredyates]

I'm still in the very preliminary stages of using an autopilot, but the SV42 seems to have plenty of power for pitch, and if there was an easy way to do it, I wish I could try a 32. I haven't yet come across anyone who has tried a 32 and found it to be inadequate. I'm using the 32 for roll, and it does occasionally slip, but that may be related to the adverse yaw. If the system is commanding a turn and only using the ailerons, it isn't going to turn very well, regardless of how powerful the servo is. I have another 42 on hand to install on the rudder, but haven't had time to work with it yet. Some builders have taken measures to reduce adverse yaw, which might help the system. I also have not yet taken a cross-country trip since installing the pitch and roll, so I'm not able to report on how well it does with straight and level over the long term. In the case of the Dynon servos, each model number increase is a pound heavier. So the 42 is a pound heavier than the 32, etc. I hope to have more info soon, but these days it has been hard to take the airplane out of service for "optional improvements" when there is flying to do and the rest of life to live. Last year I had about 5 months of downtime for various improvements.

[Erbman]

I have had the Trutrak ADI Pilot II autopilot on 4-place Bearhawk #164 since it was new, and the airplane has over 500 hours on it now. I use the autopilot most of the time in cruise, and once I got the gains dialed in to where I wanted them years ago it works fabulously. This autopilot is only useful in cruise, as it will hold a track, follow a GPS course, and hold altitude. It will also do shallow bank turns. None of that other fancy stuff. No problems with the servos being strong enough--most of the time they just barely move the controls.

I don't know why anyone thinks that "there is a lot of adverse yaw with all of the Bearhawks". Speaking from experience, I would say that is very much untrue. However, consider my experience with over 1000 glider hours. Gliders have massive adverse yaw, to the point it is rather comical. By comparison, Bearhawks have virtually none. Also consider that I installed the strongest springs I could find with the appropriate stretch on the rudder pedals to maximize the pedal-free directional stability. Prior to that I would have a lot of yawing in turbulence. With the strong springs it was reduced to an acceptable amount.

With just two servos (aileron and elevator) it flies and turns just fine. One time I had the autopilot on, but forgot and thought the copilot was flying. I couldn't tell the difference.

The ADI Pilot II is no longer available, but has been superseded by their current models.

An autopilot is a great workload reducer, especially if your right seat passenger has no piloting skills. I'd hate to think of doing a long cross country without one.

[MattS]

Russ, Do you happen to know what type rudder springs you have? Part no from Aircraft spruce? or just purchased from the local hardware store? Thanks! Matt

[Wmilbauer]

I have purchased 5 different springs trying to find the correct one without success. I finally gave up and ordered springs from Glasair. The same spring used on my sportsman. The spring required a 1 3/4 metal extension but enables me to adjust the turnbuckles so it will fly in trim in cruise flight.

[Battson]

I really enjoyed the Dynon autopilot in the four place I used (FHR). I did a few hours in that machine all up, and switched it in and out many times.
It is definitely powerful enough for positive control without breaking anything. This was only two axis, but I didn't mind keeping my feet stationary on the pedals - ideally you want three axis for long flights.

Issues:

- It did take some tuning for really long cruise flights, otherwise you can see a little hunting after it's been engaged for a while.

- The SV42 is strong enough to break the shear pin if you get the calibration wrong.

[JimParker256]

I don't know why anyone thinks that "there is a lot of adverse yaw with all of the Bearhawks".

To someone coming from sailplanes, I'm sure the Bearhawk feels like there is little to no adverse yaw. But most of us are moving from "spam cans" to the Bearhawks, and moving in that direction, there is a marked increase in adverse yaw, as commented on by almost every "test pilot" who has flown the airplanes. All of them agree that it certainly is not excessive, and definitely not something that would be considered as "dangerous" by any stretch of the imagination...

My demo flight in the back seat of Mark's Patrol's made me acutely aware that you need to lead the turns with just a bit of rudder, or else you won't get a coordinated turn. Again, it's not excessive, and within a few minutes even this not-yet-tailwheel-rated pilot was doing OK at keeping the ball at least "close" to centered. But it was a LOT different than flying the Grumman Traveler or Commander 114 airplanes that I flew for a couple of hundred hours before my test flight, where you could basically fly with your feet flat on the floor once takeoff was completed... In hindsight, though, I believe the Patrol's adverse yaw is considerably lower than what I experience in my '65 Citabria 7ECA...

But I was mostly wondering whether if you don't have a yaw damper, and have "newby" back-seat passengers, a single-axis autopilot could cause the tail to wag a bit when the AP turns the airplane. And nothing makes a new-to-aviation passenger airsick faster than a tail-wagging flight. That effect is amplified by riding in the back of a tandem airplane... Keep the ball centered, and most people are OK. Let the ball start moving side-to-side, and inexperienced passengers will begin to feel nauseous. That's why I was asking the question - the impact on "back seat" riders more so than how it feels to an experienced (especially sailplane experienced) pilot...

[Bdflies]

Jim,
If you base your decision on the worst case situation (newbie back seat passenger, bumpy turbulence on an extended ride) then you must get the 3rd axis. The Patrol is really fairly benign, in terms of adverse yaw, but it's not a 'feet on the floor' kind of plane.
Mine does not have the third axis. It works very well. If it's windy and gusty, I won't bring a newby for a joy ride. If I were making a trip and had to bring such a passenger - in gusty conditions, I probably won't use the autopilot. But honestly, if it's that windy, I won't enjoy the flight either. I'd probably drive... Hey, it's casual.

Bill

[JimParker256]

Good points. I will probably do a single-axis to start with, and see how it works out. To your point, I guess if I have a passenger, I could just avoid using the AP, and use those pedal-thingies myself... LOL

[Bcone1381]

I would like to go back to Tims original question about Auto Pilot advice,

I have no experience with Autopilots on a Bearhawk. But thought I would share about a culture that existed in the previous century when an auto pilot was not option in most piston aircraft, and some turbine aircraft.

I use to fly a C-310, and a Baron single pilot, no autopilot at night in the Great Lakes area (Cleveland, Detroit, Buffalo, Toledo, Pittsburg, Etc) about 80 hours a month. I use to play games with myself on flights....I think the games started when I was looking ahead at taking the ATP check ride which had altitude tolerances of +/- 50'. I figured if the minimum standard was 50' then I should set my personal altitude tolerance at 20'. Well.....to put it bluntly, I sucked! SO, I started timing myself to see how long I could hold it......Game on----I watched the clock, I celebrated thirty seconds at first, then I made a minute, then 3 minutes.... on it went always trying to beat my old record.

Then it expanded into seeing how long I could keep the tolerance using only elevator trim. (I love manual trim...it was way easier to do this than using the electric trim) I developed a cushion around my 20' tolerance when I kept the altimeter needle inside of the BIG ZERO at the 12 o'clock position the altimeter. By the time I took my ATP check ride, keeping -0/+50' during a circling approach was no sweat. It was about four more years and a couple more thousand hours before I flew my first airplane with an autopilot. I continued to play that game during those years.

For Twenty Five years now, I have been flying with autopilots. I am not that good any more. I know some may think "Thats a Stupid game for a dyslexic mind with ADD" But I can tell you Everyone can develop that skill fairly quickly, yet you won't if you have an Autopilot. You will miss out. You won't be that good either.

The experimental market is different these days with all the great l products with a value pricing. But, the cost and weight can add up, remove utility and enjoyment that simplicity can provide. Dont sweat the NEED for a yaw damper. You will figure out a way to compensate if that becomes an issue, and you may hone a new skill while doing so.