audiohavoc
Reply #85 - Today at 12:25am   I have a question about the VOR/LOC mode of the autopilot.  It is my experience that the CS 727 has a difficult time keeping the CDI centered on a radial of a VOR, and it tends to wander a bit when tracking.  I find that I have to use HDG select mode to manually track radials while the A/P is in the VOR/LOC mode.  This is also how I correct for winds.  Is this normal or user error?  I have the CS 727-100 2.4 version installed with the flight model modification, altitude fix, MDA fix, and EPR mod.  I am using this with FSX Acceleration and Windows 7 64.

I just took the 727 for a test trip around the PNW and tried a few VOR intercepts. I gave it a good workout by being close to the VOR - around 30 miles - and at high speed -300 KTS. I put the autopilot on, with heading select and put the plane on an intercept heading for a selected radial. Here is where I find a problem. When on an intercept heading, and the radial not captured (I made sure I was a long way from capture of the radial) when you are in heading select and you put the autopilot in NAV/LOC, the progress display lights for NAV/LOC should be amber (armed for capture) and the heading light should be green. When the computer sees the radial coming alive, the amber should change to green (capture) and heading select should trip to off. This tripping off of HDG is not happening. I believe forum member CoolP has collected this bug in his summary to CS. When I fly the ILS in this plane and set the autopilot on an intercept heading using HDG select and then arm AUTO G/S I get the proper display on the approach progress lights and the HDG does trip off on LOC intercept. Why it acts in a different manner with the VOR is a mystery to me.  :-/

For now, when I see the radial start to come alive, I trip off the heading select and the NAV/LOC part then works fine. The autopilot waits a bit longer than I would to start the turn towards the course, but it does turn and intercept the radial and after a small correction, tracks the radial just fine without any zig zags.

Play with the autopilot a bit more and let this forum know your findings.

Lou