Short of creating my own autopilot functions to capture and follow the localiser/glideslope, does anyone know if it's possible to damp the autopilot's irritating insistance on turning right before turning back to pick up a localiser that's to the left of the aircraft? It exhibits this behaviour even if the CDI deflection is almost zero when the autopilot is engaged; I've tested down to a CDI deflection of -0.0065 and it still turns right, flys out to a CDI deflection of just under -2.0 before turning back to capture the localiser.The nice thing to do would be to capture and follow the localiser heading instead and then engage approach mode, but of course, KEY_AP_APR_HOLD also engages the localiser hold and.... here we go again. Using KEY_AP_LOC_HOLD_OFF immediately after calling KEY_AP_APR_HOLD_ON causes the glideslope hold to flicker on and off approx twice a second and GS hold never engages, so following the heading is a no-go trick.Hold on while I reach for the aspirin....-Dai

In the absence of any replies, can anyone confirm that this is absolutely NOT possible? I can then add the info to the sd2gau series. I no longer need the info myself as I've written my own LOC/APPR autopilot code.-Dai

Dai, somewhere in the distant past I did find that the shallower the angle of intercept, the less the tendency to do the "reverse hunt" was...What I did was use the default commands, but wrote a bit of code that automatically triggered a heading/intercept routine such that the a/c will fly towards the desired intercept track, then begin a series of shallow "aileron turns" beginning at 1/2 nm from the track, and then switched to pure NAV HOLD mode at 1/8th nm from the track.By that time the a/c has a very shallow intercept angle of ~2 degrees or less.

Hi BillThat figures with what I accidently found while writing the glideslope hold. I set up a flight using _LOC_HOLD as in this bird LOC has to be active before APPR can be engaged; CDI deflection was only just off zero and as I released the flight, no hunting. I still found that at ~2 degrees the hunting was unacceptable.I was going to try the NAV_HOLD trick for localiser hold today; it's nice to know that it will work! :( It's going to be fun because I have bank angle restrictions when capturing LOC....-Dai

Okay, on re-reading my description, I see that I left off the critical bits following NAV_HOLD...Once in NAV_HOLD mode, the GS (if available!) is monitored and the routine will automatically enable APR mode whenever the GS signal is acquired. If no GS is available, then the routine will automatically enable APR mode and allow FS to handle the switch from NAV to APR as usual.