Aspen issues

Aztec Driver

Line Up and Wait
Joined
Mar 7, 2005
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Location
Elizabethtown, PA
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Bryon
Anyone have a Twin Comanche with an Aspen unit installed?

I really love my Twinkie, and I really enjoy flying behind the Aspen, but I have come across a problem that has been giving me fits on most of my longer cross country flights since I had it installed in 2010. Was never much of an issue, but it was enough to make me have things checked a few times.

Every time I took a long flight, with baggage in the rear baggage compartment, I noticed that the heading indicator on the Aspen unit would be 10-15 degrees off, compared to the compass, sometimes more, sometimes less. It differed slightly depending on what heading I was on. On the ground, it would always seem to be accurate. Between my Avionics guru and myself, we could never duplicate the problem on the ground, or even in the air on local checkout flights. He recalibrated the Aspen, and checked placement of all components. He did say that he did not like the placement of the RSM, but there were too many cables and pulleys and fittings to place it anywhere else.

I dealt with it throughout the years, as it was never far enough off to cause an issue, until just after annual this year. The heading indicator was 50 degrees off of the compass and stayed there. After looking at everything, and consulting with him again, I determined the problem. It was all because I had put my bungee removal tool in the baggage compartment, directly above the sensing module. Took it out and it was back to right on again. Turns out that when I pack things, I likely was putting something directly over the module to cause it to be deflected slightly when I pack for long trips.

So I have to be careful what I put in the baggage compartment, lest the heading goes off.

Anyone ever have this problem with their Aspen?

I lent my airplane out to a friend this weekend, and warned him to be careful what he put in the baggage compartment. He ended up putting and IPAD, charging dock and BOSE speaker hookup directly over the RSM, causing it to slowly spin the heading indicator portion of the Aspen, in IMC. Luckily, he is proficient, and "partial panel" on this is pretty much a full 6 pack of instruments.

Anyone else have a Twinkie with an Aspen? Where is your RSM mounted and did your Avionics person say there was no other place to install it?
 
Not a Twinkie but avionics guy noted that the sensor module placement was critical. Are you getting reliability warnings? I get those on the Aspen when the heading sensor is out of calibration. I'm guessing the difference between the GPS heading and the mag heading drives the wind calc nuts.
 
I bought a Dakota last year with Aspen 1500 and I started noticing heading drifts of up to 15d at times so avionics shop did some testing and determined the R&M was in a bad spot and getting interference from cabin speaker and copilot shoulder harness so they moverd it to just aft of the rear hat shelf bulkhead and to the right of center and degaussed the fresh air vent cable and now it's all good but they warned against storing headsets (magnets) on the hat shelve.
 
Don't most new builds put the magnetic sensor out on a wingtip?
 
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