On Dec 20, 6:14 am, Paul kgyy wrote:
It's my understanding that the STEC autopilots get their "bank"
information from the gyro in the turn coordinator while other systems
derive this from the vacuum-driven horizon indicator.

Are there any TSO'd systems other than STEC that do this? I ask the
question because STEC's new owners are preparing to milk this cow to
death by raising the system prices by 2 AMU, and some serious
competition would be welcome.

I consider the TC based system better because the TC is a much more
reliable instrument than the AHI.

Most GA autopilots work off the TC. Auto pilots that work off the
attitude indicator tend to be much more expensive. The downside of TC
based autopilots (such as mine) is that any yawing motion during
turbulance causes the plane to lose coordination and; therefore the TC
may indicate a bank in the wrong direction (the TC is only good when
you are coordinated). As a result, in my experience, attitude based
autopilots are better in turb. However, for the $$$$ TC based systems
are the best value.

-robert