Autopilot "fix"

[Kronzky 34]

That's a different AP issue...

The one we're talking about here is where normally the autopilot works just fine, but once in a while it totally loses its mind, and tries to pivot you into the ground. 

[AKBush 0]

"Decided to do a quick flight from Cardiff to London in the A320. Very hard to get it to maintain VS mode during climb, it boosted to a ridiculous 5000fpm instead of 1800."

Not as ridiculous as you might think.  Some years ago I flew jump seat with a Lufthansa pilot friend in an A318 (slightly shorter fuselage but same engines as the A320.) On autopilot and climbing out of Bologna with a light load, we saw well over 4,000 fpm on the VSI.

[Stratocruiser1 134]

My problem is with the auto pilot on the Retrofit panel. No matter what heading I dial in, when I hit the HEADING button on the auto pilot panel, the DC-3 turns to North and maintains that heading. It only happens on the DC-3. The same panel is used on other aircraft, and they all work properly. I have tried two different addon mods for the DC-3, but they do not solve the problem.