Good info, Bob.  And yes, I disconnected the static system feed line from the instrument manifold before blowing.

Did other folks put in a static system drain?  I did not; and am adding a static system blowout to my annual checklist.  Takes about 5 minutes.

Final note -- my Sorceror has been great too, and I presume that any autopilot would have the same problem with this static system blockage.

On Mar 7, 2013, at 7:44 AM, Robert R Pastusek wrote:

Charlie,
It's possible that a very small amount of water in the static lines was dissipated when you blew on it. Doesn't take but a drop to cause a problem...and the autopilot is looking for a pressure change MUCH smaller than would be needed to move the needles on your altimeters. The static system doesn't have to be exactly correct to drive the autopilot (as it needs to be for the altimeters), but it must be capable of transmitting the smallest change to the autopilot.

Be especially careful about applying compressed air to the static system. If you have ANY static instruments attached, you risk damaging them. 90 PSI is well beyond their operating capacity.

Good troubleshooting out there! My TruTrak autopilot has been a true gem...after I got it calibrated and tuned...for the past five years/800 flight hours (IV-P with Chelton EFIS).

BOB