The following is from Dynon's web site:

Test Program Update

Dynon has been working with a small fleet of testers on the flight dynamics and performance qualities of the Autopilot for a few months now. So far, the Dynon Autopilot is flying a diverse set of aircraft, including examples of the RV-4, RV-6, RV-7, RV-8, RV-9, Glasair Sportsman 2+2, Sonex, SeaRay, BD-4, and more. People familiar with these aircraft will recognize that this represents a fairly wide range of stability profiles and performance characteristics. As we move forward, we will continue to add experience in different aircraft.

Needless to say, the diversity of aircraft involved gave them a good idea of what to expect once the autopilots were installed in customer's airplanes.

The following pictures and comments are mine alone and in no way should be construed as the final say on the installation of any autopilot/airplane combination.  If you have questions regarding your installation, I highly recommend you contact the experts at Dynon and check the Dynon Support Forum.

E Installing the AP74 was easy enough.  Cut a rectangular hole in the panel and slide the thing in place.  Only one problem, I didn't like the standard Dynon retention bracket because it required drilling holes in my finished panel, countersinking for flush rivets, and finally riveting it in place.  This would damage the panel and I didn't want to have pull the panel out to refinish it.

F Thus I developed this retention bracket and it is my understanding Dynion is going to put a similar unit into production.  Should you elect to copy my diagram, note that the retention screw in the AP76 may be in a different place, thus you may have to modify this when upgrading.  Either way, it sure beats drilling out rivets in your panel for the upgrade.

Note that the first two pictures show the AP74 being installed in scrap piece of aluminum and not in my actual panel.  The good news is the retention bracket worked great on the actual panel.

Servo Installation:

E To make future maintenance easier, I added DB9 connectors to both servos.  This diagram includes the pin-out I used on the connector.  Verify this diagram with your installation documentation from Dynon.  The schematic shown was taken from a pre-production document and may not be accurate.

Servo DB9 Pin out

(Male on servo)

1 – Power – Red

2 –

3 – DSAB A – Green

4 – Unused – Wht/Grn

5 – Disengage – Yellow

6 – DSAB B – Blue

7 – Unused – Wht/Blu

8 –

9 – Ground – Black

F Here is a picture of both servos with the DB9 connectors installed.  Should these ever go in for maintenance or replacement, I suspect I'll be installing a new DB9 connector.  Note the shrink tubing used on the wires.

E As mentioned earlier, installing the pitch servo is a challenge on a completed plane, mostly because you are working on your hands and knees.  That and I elected to drill and rivet through the floor of my plane.

F Installing the pitch servo was easy enough and there was no interference with the push tube but as you can see, it is close.  Don't forget to safety wire the thing in place.  The last thing you want is a servo coming loose and jamming your controls.

E Connecting the servos with a DB9 connector made the installation easier as it allowed me to simply plug the thing in, once it was secured to the bracket.  Note how the zip-tie pad is glued to the rib, the DB9 shells are zip-tied together, and then both are zip-tied to the pad.  This makes for an easy and clean installation.

F Installing the roll servo is VERY easy when compared to the pitch servo.  Simply remove the lower aileron bell crank bracket, install the one provided by Dynon, bolt on the extra plate, servo, push rod, connect the wires and you are ready to go.  Because of the limited space within the wing, it was difficult to get a good picture.

Note: Dynon provides brackets which are designed to limit the servo travel to prevent the servos from going "over center" and jamming the controls.  It is up to you, the installer to determine if these are required for your installation.

The pictures and descriptions above are not intended to be used as an installation guide.  Remember, you are making major changes to your flight controls and there is always the risk of introducing something that could jam your flight controls.  Be careful when installing this or any autopilot!

Electrical connection to both servos and the AP74 are through a dedicated 5A pullable circuit breaker.  This is a highly desirable configuration as power to the servos can be easily removed should the need arise.  If your installation uses automotive fuses, it is highly recommended you add a disconnect switch which is easily accessible to the pilot.

Autopilot Impressions:

Dynon has done an outstanding job of integrating their EFIS with modern stepper motor technology to develop an easy to install and use two axis autopilot!

The hardware installation is easy as is the software configuration and operation.  When activated there is a small icon on the lower left of the screen indicating if the AP is operating in either pitch, roll, or both and what navigation source is driving the heading, if any.

In addition, they have incorporated a 180 degree about face button on the AP74/76 as well as made it available through the menu system on the EFIS.  This has the ability to save many lives should a VFR pilot in advertently fly into IFR conditions.  Just press the 180 button and let go.  It will reverse course and fly out of "the soup" on it's own.

There are too many features for me to describe on this web page.  Needless to say, I'm very happy to add their autopilot to my airplane.

A number of people have asked me if I can notice the servos through the control stick.  The answer is yes and no.  On the ground, with no air loads on the control surfaces, the servos can be felt but in the air, I could not tell the difference.

The servos are designed to be overpowered by the pilot, should they command something the pilot does not wish to do.  There is also a shear pin in the servos that can be broken, should the servos jam.