Installing an Autopilot--A Revolution in Flying!

I hand flew DKX for over 20 years.  During that time we flew mulitple trips to Virginia (to see my daughter who lives there), Florida and the Bahamas (for vacations).

I was always interested in installing an autopilot to lessen the workload and make long distance flying more relaxing.  Unfortunately, the STEC autopilot that was certified for 172's was a freaking fortune.  Installed cost was $15-20K which was almost half the cost of the airplane.  Clearly, a non-starter for someone on a budget like me.

At Oshkosh two year ago, I learned of a company called TruTrak that had just certified a 2-axis autopilot for C172's.  Cost of the unit was $5000!  After some research, I learned that I could install the unit myself under the supervision of my mechanic.  I called Chris, my AME and he said, yes, he knew about the unit and would be happy to work with me installing it in my plane.  Whoo hoo!  I  was one of the first guys in line to place an order!!

It arrived in September of that year and the installation began!

First task was to install the roll servo in the right wing.  The servo is held in place by two brackets that are bolted to the rear wing spar.  This obviously involved drilling the spar which kind of freaked me out.  But it wasn't that bad.  The installation instructions are excellent.  The autopilot had originally been developed for the home builder market, so they assume you are not an expert AME.

Following the template, I was able to carefully drill the holes for the backets.  The one mistake I made was trying to drill some of the holes from inside the wing (following their instructions) using a right angle air powered drill that I borrowed from my AME.  It was way too awkward and I ended up screwing up one hole!

Fortunately, I was able to move the nutplate on the backet to accomodate my mistake.  After that, I drilled all holes from outside the wing.  I then mounted the servo in the wing quite easily.

The servo connects to the aileron bellcrank using a pushrod.  I really like the use of a pushrod as you don't have to disturb the aileron control cables.

However, you do need to remove the bolt holding the bellcrank to faciliate creating an attach point for the pushrod.  I debated doing that myself in my hangar at Edenvale (where I was doing all the work. My mechanic is 50 miles away in Peterborough).  But I figured if I couldn't get it back together again, I was screwed because I then couldn't fly the plane to Peterborough for his help.

Thank goodness I didn't remove it!  It was crazy hard getting the bolt back in place and I really needed Chris' help.  It's so nice knowing you have an experienced AME as a back-up when you get in trouble!!

Next came the pitch servo which mounts under the instrument panel and actuates directly on the control column, again using a small pushrod.  This bracket had to be attached to the tunnel on the floor of the plane, just aft of the firewall.  There is not a lot of room under the panel of a 172.  It took some awkward attempts to drill the holes and then squeeze the nutplates onto the tunnel.  The secret is to really take your time, use lots of light and clear stuff out of the way to make access as easy as possible.

Once the two servos were installed, the wiring had to be run from under the panel (where the control unit is located in an empty instrument hole) to the servo in the wing.  I did that but left the harness unconnected under the panel.  That would be Chris' job.  There was no way I could make the terminal connections needed to hook up the wiring harness.

Chris also connected the control unit to the pitot/static system.  Again, there was no way I was going to cut into the airspeed and altimeter lines myself.  That task was way beyond my pay grade.

I flew the plane to Chris place and left it there for him to complete the installation.  He had everything hooked up in less than a day.  I had my brother-in-law drive me back out and I made the first flight!!  The a/p worked perfectly!  It was so cool sitting there in straight and level flight and then engaging the a/p for the first time.  Initially, you don't feel anything but the controls seem to stiffen up and then you see them moving very impreceptably keeping the plane s&l.  So cool!!

The TruTrak a/p will easily follow a course driven by a handheld GPS so we connected it to my Garmin Aera 660 GPS which is mounted on the pilot's control yoke.  It is amazing.  Once a course is set, the unit will follow the waypoints and the altitude hold feature keeps the plane dead level.

Since installation, we have flown the plane to Lynchburg and back several times and to the Bahamas last March.  It has totally transformed my flying, both VFR and IFR, especially IFR.  It's so much more relaxing just sitting there and monitoring everything.

They say that certain technologies revolutionize flying in broad leaps.  The first (in my flying experience) was GPS.  It completely changed cross country navigation.  The second was satellite based weather.  My SiriusXM subscription weather service has literally saved my bacon multiple times.  I simply won't fly without it.

And now, reasonably priced digital autopilots have added a huge measure of comfort and safely to flying little planes.  My wife in particular loves the blue "Level" button.  I tell her that if I have the big one in flight, just push the blue button.  The plane will automatically maintain level flight.  Then push the red transmit button and yell for help.  ATC will take over from there.  (At least that's the theory).  She feels really good about that.

So the a/p installation has been a total success!  I love it and my wife loves it.  It can't get any better than that!!