Jon Kraus wrote:
snip

- innermost loop controls roll with ailerons and
taking reference from horizon gyro,

Wrong....

S-tec AP's do not take any info from the AI. They are rate based not
attitude based and get their roll info from the Turn Coordinator.

The GPS Steer function is a true wonder to behold. Both in simplicity
and accuracy. You know not of which you speak... No offense... :-)


Yep, watching the STEC track the GNS480 in the GPSS is a true wonder.