P3D - C182 - Autopilot - Connect/Disconnect Issue

[Mysty]

Good day,

I've been flying with P3DV4 and the A2A C172 for several months and everything was good. I purchased the A2A C182 a few days ago and have had the following problem since then. The Autopilot connects as it should when I press the Z key. However, when the Numeric Pad keys 1 or 7 is pressed, it disconnects the Autopilot as if I pressed the Z key. If i press the Numeric Pad Keys 1 or 7 again, it doesn't reconnect the Autopilot. It only disconnects it. The P3DV4 default keys for Numeric Pad keys 1 and 7 are Elevator Trim (Up) and Elevator Trim (Down) respectively. I do have Logitech X-56, but I disconnected them and the same behavior occurs. I tried it on the default planes that comes with P3DV4 and cannot replicate this issue. It seems to only occur with A2A C172 and A2A C182 since I purchased the latter.

Any help would be greatly appreciated.

Mysty

[Oracle427]

This is real world behavior. Using the electric trim with the autopilot engaged will disconnect the autopilot. You will need to use the autopilot vertical modes to make altitude changes, or disconnect and hand fly to a new altitude and then re-engage.

[Mysty]

Thank you very much Oracle427 for your quick response. I wasn't aware of that.

Mysty

[Nick - A2A]

Hi Mysty,

Yes, as Oracle says, the manual electric trim buttons on the yoke will send a disconnect signal to the autopilot. This is one of the real world safety features of the KAP 140 installation which is modelled. Another safety feature which is simulated is that it's necessary to press and hold the AP button for at least 0.25 seconds to engage the autopilot.

Thanks,
Nick

[Oracle427]

In addition IRL, and this is not modeled by A2A, if one pushes or pulls on the yoke while the AP is engaged, the autopilot will trim against the control pressure from the pilot.

So if the pilot pulls on the yoke, even very gently, the autopilot servo will push nose down against it and also roll in nose down trim.

The reason is because the autopilot has no idea whether it is the pilot or aerodynamic forces that are causing the yoke to move. The autopilot takes the same appropriate corrective action regardless.

If pressure is held in by the pilot, the autopilot will continue to add trim input and the pitch servo will continue to resist the pressure from the pilot. The result being that pilot does not feel the excessive trim force being added by the autopilot while the servo is active.

At some point the autopilot will throw an error as part of a safeguard against a runway trim condition. When the AP disengages, the pitch servo will disengage and the pilot will suddenly feel the force aerodynamic forces through the yoke from a very out of trim aircraft. This can be very exciting in very bad way. This is not so uncommon an issue for unwary pilots that fly with their hands on the yoke while the AP is engaged with these "simple" AP systems.