Matt2218 wrote on Jan 28^th, 2010 at 11:43am:

Quick question for you Mark... I'm using the Acceleration version 2.3 autopilot (not any of my modified ones  8-)) and I find that in order to capture the localizer I must manually turn off "hold heading" switch, and if I want to capture the glideslope I must manually turn off the "altitude hold" switch. Does the autopilot automatically shut these things off for you when you rotate the knob to NAV/LOC or AUTO GS? Not that switching them off is a big deal for me, I'm just curious.

Hi Matt

I'm using FSX + Acceleration too. And here is what I do.

I rotate the knob to NAV LOC with HDG SEL and ALT HOLD on while heading to intercept the Localizer.
I turn HDG SEL off as soon as the Localizer needle starts to move¹.
I turn the Altitude Hold switch OFF² and turn the main knob to AUTO GS³. Those two MUST be done just before the Glide Slope reaches the Altitude I am holding.
It is very important to make sure I do those three things at the times I have mentioned. Or else...
If I switch the HDG SEL too long after the Localizer starts closing in, the AP will spend too much of its time time trying to catch the localizer and MOST times it WONT succeed.
If I switch off the ALT HOLD after the Glide Slope has passed my altitude the Autopilot wont chase it. BUT. If I lose altitude AND try to catch it all hell usually breaks loose and the plane is very hard to control.
If any of these situations goes horribly wrong. I either abort the landing (Go Around) or continue on to try and land manually. A Go Around is really the best option (but sometimes I'm too stubborn and wind up doing a very, very messy landing).

When the Autopilot is in NAV LOC mode, it WILL turn of the HDG SEL switch! But it does it TOO LATE (UNLESS the angle of the intercept is very shallow. I think it is 10 degrees or less)!

I hope this helps.

Mark