KAP140 Autopilot Details

"Craig Prouse" wrote in message ...

If I recall correctly, those S-Tec autopilots require the pilot to establish
the aircraft on course before engaging the NAV course tracking mode. Once
on course, the error signal from the CDI is probably sufficient to remain
there.

Depends which model you have. The 20/30 will not intercept a course, just hold it.
The more expensive ones in the line will intercept the course.

"Ron Natalie" wrote:

Depends which model you have. The 20/30 will not intercept a course, just
hold it.

Yes, when I said "those S-Tec autopilots" I was referring specifically to
"those," the 20/30.


The more expensive ones in the line will intercept the course.

The KAP 140 is similar in many respects to the S-Tec 55. Actually the 55 is
a little nicer in several ways. I expect that the 55 would also require a
heading reference to support its intercept feature.

It seems like a heading reference might improve the ability of an autopilot
to maintain course precisely or at least reduce any tendency to weave or
hunt while bracketing the course. Would anyone with direct experience like
to offer a comparison?

"Craig Prouse" wrote:
It seems like a heading reference might improve the ability of an
autopilot to maintain course precisely or at least reduce any
tendency to weave or hunt while bracketing the course. Would
anyone with direct experience like to offer a comparison?

I can only testify about my S-Tec 50, which is the same in this
respect as the 20 or 30. It works strictly off CDI deflection and rate
of turn. I don't think there is room for improvement. Using the GPS
CDI, once established on a track, it will maintain a xtrack error of
just a few feet without hunting. That is with the autopilot set to
"approach" sensitivity and the GPS CDI scale set to one mile.
--
Dan
C172RG at BFM