I had John of STARK AVIONICS do a complete panel upgrade on my RV7 earlier this year (dual Dynon Skyview HDX, ADSB in/out, Avidyne IFD440, SV knob Panel, & SV AP Panel). After the usual and expected delays, I get the call that the aircraft is ready, so I show up the next day and wait 4-5 hrs while work is finished. I do a thorough preflight (AP, trim movement and position, etc) and taxi out for my first test flight. Run up completed, and checklists accomplished I taxi onto the runway and begin my takeoff roll. At liftoff I notice a full nose up, out of trim condition. I activate the trim switch to try and correct the situation, but the trim does not respond. I call the tower, and ask for and get clearance for an immediate landing. After landing, I taxi back to STARK AVIONICS and report the problem. My thought at this point, is that maybe the trim is wired backwards. It's now late in the day, and I decide to rent a car and drive back home ( 5 1/2 hrs). The next day John says he believes that they have solved the problem, and I can come take delivery of the aircraft. I find a friend to fly me back. Once again the test flight ends with the same results. It's now late in the day, so I check in to a local hotel and spend the night. The next day after another failed test flight, we decide to check the trim operation with the engine running, where we found the trim function to be intermittent with the engine running. After consulting with Dynon it is suspected that I have a bad SV AP Panel, so John wires the trim to bypasses the SV AP Panel. And I fly the aircraft home to await the arrival of a new/repaired Panel.
With the new panel installed I accomplish a ground trim check with the engine running, and get the same results as before-intermittent trim response. I once again bypass the trim to the SV AP Panel, and give JESSE SAINT, of SAINT AVIATION a call. Jesse was able to diagnose this problem almost immediately. The problem turned out to be that during the install, Stark failed to remove the trim relay that was installed in the aircraft. As explained to me my Jesse, the SV AP Panel has its own trim relay within, and cannot/ will not work when two are installed. I noticed this warning in the install manual, which Jesse seemed to be very knowledgeable of:
If two SV-AP-PANELs are installed, connect only one SV-AP-PANEL to control trim motors. Do not connect the second SV-AP-PANEL’s D15M connector in parallel with the first SV-AP-PANEL’s D15M connector – doing so could cause unexpected behaviour and/or damage to the units and the trim motors.
Jesse's knowledge of this system amazes me. What surprised me was that even Dynon failed to question this during the calls from Stark during the initial troubleshooting. I cannot say enough about Jesse"s knowledge and professionalism. He is simply AMAZING! I would highly recommend him to anyone who ask.
Post note:
I just had Jesse and staff complete my first Condition Inspection since purchasing N900EC, where we found and corrected at least 3 other problems with this initial install by Stark Avionics:
1) Placement of dual ADAHRS-cable to pilots shoulder harness rubbing against the units causing a mismatch in attitude
Solution: relocated to center of tailcone to avoid interference
2)dual temperature probes installed on bottom of fuselage in exhaust stream resulting in inaccurate temperature readings.
Solution: relocated to either side of fuselage under Horizontal Stab
3) failed to remove unneeded trim position indicator which caused inaccurate readings
Solution: removed unneeded trim position indicator. Trim motor relays trim position.
Once again Jesse's systems knowledge is amazing! If you have a Vans RV, and need maintenance/Avionics work Jesse is your man!