Trutrak's Altitude Hold

After 800 hours of flying, I felt I was about 750hrs past due for an altitude hold unit. I originally installed the EZtrim unit but was unsatisfied. The EZtrim unit would work fine I believe in a slower more pitch stable plane. But not the RV. In fact, pitch sensitivity is probably the only complaint I have with the RV in terms of its flight characteristics. EZtrim uses your trim servo (MAC in my case) to adjust altitude. Well the elev pitch servo is too slow. For $250 on the EZtrim, I figured it was a buy risk worth taking.

Normally, I am not first out of the gate on new technology in my plane, but the folks at Trutrak are not new to this stuff. I did wait for the first pirep from an RV'er before i bought. But I have mine installed in less than a week from their release of the product.

I fly alot, 800 hours in the past year and one half.  I find near 80% of my time IFR is spent managing altitude. Unacceptable I decided early on. But it was not until the Altrak unit came into play that something was affordable enough for me to take the plunge.

I tried and tried for 2 years to get Navaid to get into the altitude hold market. I have thoroughly enjoyed the wing unit. But no joy on alt. hold. So off I went to purchase the Altrak unit. Overnighted to my home, installed next day.

Installation was pretty easy, 8 hours soup to nuts.  First the harness from the servo to the module needs to be fabricated. On the bench, I made a little harness. Soldering to both a 9 and 15 pin d-sub. I hate them little solder pins. They are so tiny.

Next onto another wonderful job of removing the baggage floors, wall, and sides to get into the tailcone to mount and run wires. Here are some various install pics. This was really a nice and easy installation.

Installation manual said a static line was optional in a non-pressurized plane. Since the static line was nearby, I went ahead and teed the static and installed the dedicated static line.

Finally one of my favorite parts, the single button on the panel. With my hand on the throttle, I can control the Navaid and Trutrak with my index finger. I like that a lot.


As of this writing, I have 4 hours on the unit. Hi res photo's can be d/l'd had here.(4mb zip file)

Thinks I like..
1) Single button on the panel, push it in, green light, and your on. Nice
2) Price/Value is good, especially for me. I fly alot.
3) High quality product, as is seen and felt in playing with the unit
4) holds alt in smooth air +-10ft, lt-mod turb +-30 feet
5) turns <20deg +-20 feet, turns <45deg +-50 feet, turns >45deg +-80feet
6) It is very smooth. I was concerned about feeling the unit operate in my butt, but I can't. I am very happy with that.
7)  I have so much time on my hands now, I need in-flight entertainment, and a coffee maker to keep me awake. It has freed up
way more time for other duties, much more than I hoped it would.

Things I did not like...
1) Servo is heavy. I do not have a scale to weigh it, but Ill bet it is 3 times the weight of the NavAid servo in my wing. 2 1/2 lbs I'd say. No doubt this servo is of higher quality, but damn.... its heavy. I was not happy sticking that weight in my tailcone back there. Every time I picked it up, my face would crinkle in disgust. I seriously considered putting it back in the box and returning it for that reason alone. But I didn't. And I am glad I didn't return it. Again obviously it is a very well made unit. And in the world of plane compromises, they have opted for more quality than weight. Who am I to argue.
2) I get a noise in my headset, through my com, from the servo. Sounds like a high pitched Morris code. Faint but irritating. Paperwork said not to bother with shielding wire, so I didn't. But I have noise and now Im going to have to rip the plane apart again and put shielded wire from the tailcone to the cockpit. ARGH!! Chuck from Trutrak gave me some ideas to try on the noise problem I will work on that shortly.

All in all, the unit is definitely worth the money for me. The smoothness of the unit, combined with the time freed up in the cockpit is truly remarkable. You don't realize how much time is spent holding altitude in the RV until you don't have to anymore. I give the TruTrak guys a thumbs up on this unit.

last updated 04/28/2003