???

When I use my autopilot in the approach hold mode it will lock onto the localizer and track just fine. This happens in all airplanes.

In the four Cessna airplanes it will also lock onto the glide slope and hold it just fine. But in none of the other planes will it lock onto the glide slope.  In fact it has to be turned off because it gives a full nose down pitch and there is not enough "up elevator" to prevent it crashing well short of the Rwy.

I've studied the Panel.cfg and Aircraft.cfg files on the Cessnas, as well as the others airplanes in vain hunting for the reason but so far it has eluded me.

Does anybody out there have any reasons why this should be happening, and what to do to make the other airplanes hold on the glide slope as well ?

I anxiously await an answer.

 

Yup - the nav/gps switch is in the correct position. In fact I've tried it both ways, the glide slope won't control any aircraft except the Cessnas.

I am at a loss - sure do want some help with this.

Make sure  that you're aircraft is FULLY CONFIGURED(flaps down-gear down-speed stabilized)or very nearly configured. What the big airplanes will do sometimes  is porpoise. What this means is that if you intercept the glideslope "clean" at 200kts, the autopilot will do it's best to "chase" the glideslope but the oscillations will become worse as the the a/c nears decision height.