Have you read the POH supplement?



"Roy Smith" wrote in message
...
| My club just got a very nicely equipped Bonanza with a
King KFC-200
| A/P system installed (along with a CNX-80 GPS). I think
I've got most
| of it figured out, but yesterday something happend which I
didn't
| understand.
|
| The active leg in the GPS was a course of about 230, with
a stiff wind
| from the south. I was about 2.5 miles right of course,
and 30 miles
| from the next waypoint. I put the course pointer on 230,
the heading
| bug on 190, and selected FD, HDG, ALT, and AP-ON, and
watched the
| cross-track error on the GPS; it was decreasing slowly, so
I figured I
| had a nice shallow intercept angle set up. I then hit the
NAV
| button. The NAV and ARM lights came on, as expected.
|
| Eventually, Otto intercepted the desired course (as
indicated by the
| GPS XTE going to zero and the HSI course deviation bar
centering.
| What I expected to happen at this point was that the HDG
and ARM
| lights would go out and the CPLD light would come on, and
Otto would
| start tracking the course. Instead, it just stayed in
heading mode
| with ARM lit up, slowly taking us left of course. When I
recycled the
| NAV button, it instantly went into coupled mode and
started tracking.
|
| Is my understanding of how ARM/CPLD works in error? Is it
possible
| that the very shallow intercept angle I had set up (just a
couple of
| degrees) had somehow fooled the coupling trigger
circuitry?
|
|