Autopilot constantly disengages.

[michelip]

After engaging Autopilot in either Path Hold or Alt /Hdg. the A-10C suddenly throws itself off A/P, especially on a bombing run in CCRP after TGP locks on target. I have carefully trimmed and gently held the stick manually until plane steadies before engaging A/P, but within seconds there is a lurch (usually to the right) and A/P is lost.

I am aware of the several posts on similar problems over the years, but in my case these problems have only appeared in the past few weeks.

Can anyone help?

Regards,

Mich.

[Yurgon]

Can you post a track?

 

The only reasons I'm aware of for the AP to disengage is when the pilot commands something the AP can't handle (aka stick input while AP is engaged) or when the speed/lift changes too much for the AP to handle it.

 

A track would be the most helpful way to try and figure this out.

 

Oh, also: DCS now has an "Auto Trim" feature. Make sure it's switched off (I think it's under Options -> Gameplay).

[Greyman]

that "lurch to the right", if you are not touching the stick or pedals, sounds like a dodgy roll or yaw axis. maybe load up the windows USB game controllers setup window and look at your joystick/rudder pedals properties. keep an eye on the stick's axes and make sure that it doesn't give any unintended deflections. if it does, that would probably explain your AP issue.

 

If the deflection isn't that great, you might be able to fix it by introducing a deadzone on the associated axis, to dampen the effect of the unwanted inputs.

[michelip]

Thanks Yurgon & Greyman,

Have checked the joy's properties and there is a slight twitch when stick is touched. This only happens on right roll, and it is a small tremor which lasts about 1/2 second. I have given it a dead zone which does improve it but not a complete fix. Have contacted the Thrustmaster people for help.

Thanks again,

Mich

[Yurgon]

Have contacted the Thrustmaster people for help.

 

That certainly sounds like the culprit.

 

Which stick/HOTAS do you have? On my old TM Cougar, I cleaned the pots once or twice over the years and that helped a lot with spikes. But I'm not sure if other models are also serviceable this way. And if it's the Warthog, there should be absolutely no spiking whatsoever.

[Greyman]

it does sound like the sort of fault that a worn/dirty potentiometer would cause and, as you suggest, the Warthog doesn't use them, at least not for the main axes, so is less likely to suffer this type of issue..

[KTFBGB]

I started having issues similar to that. And other weird stuff with usb peripherals. I switched to a externally powered usb hub and all was good again. Hotas systems can get really weird if have a slight voltage drop and there is hardly any juice going to the onboard USB ports.

[Greyman]

That's a good point. I have my WH HOTAS and MFG pedals attached to a wheelstand and use a powered USB hub to give me just one USB lead to plug in, before a flying session.

 

I did once forget to plug the power lead into the hub and that caused a bit of odd behaviour on the controls, particularly with switch activations not being recognised. As all was well after powering the hub, i'd assume that the joystick, throttle and pedals simply pull too much power from the single USB port that i had plugged them into.