Programming Autothrottle Disconnect

[stevens]

He Pete,

I try to program in FSUIPC 3.7 the Autothrottle disconnect on my yoke. I would like to assign a button for disconnecting the Autothrottle.

But the only things I found in the menu for button assignment is: "Autothrottle arm" or "Autothrottle TO GA". Where can I find "Autothrottle disconnect"?

Do I have to assign it otherwise? Or is it able to assign it through the axis programming? The perfect way would be, to pull my throttle idle and that would disconnect the autothrottle then.

Any help would be much appreciated. I searched the forum for this, but couldn't get any topics to this thread. I read very often your hint, to "program the autothrottle disconnect", but i couldn't find how.

For your info, I have disabled the FS joysticks completely and have programmed all axis and buttons via FSUIPC.

Thanks in advance for your help!

Regards,

Stefan

[Pete Dowson]

I try to program in FSUIPC 3.7 the Autothrottle disconnect on my yoke. I would like to assign a button for disconnecting the Autothrottle.

But the only things I found in the menu for button assignment is: "Autothrottle arm" or "Autothrottle TO GA". Where can I find "Autothrottle disconnect"?

FSUIPC only lists these because they are the A/T controls offered by FS. FS doesn't provide an "Autothrottle disconnect" as such -- the "Arm" control toggles. You could just as easily assign these in FS's own assignments.

The perfect way would be, to pull my throttle idle and that would disconnect the autothrottle then.

Well, you can do that via the axis assignment because you can program it to send controls at certain values as well as operate an axis, but I fail to understand why you think this is "perfect" -- mostly you would want the A/T still engaged during descent even though you would have certainly pulled the throttle back to idle.

Any help would be much appreciated. I searched the forum for this, but couldn't get any topics to this thread. I read very often your hint, to "program the autothrottle disconnect", but i couldn't find how.

Where is this "hint"? I don't remember ever writing anything for A/T disconnect. FS has never provided a control to do this specifically -- only the ARM which is a toggle (i.e. it turns it on if off, off if on).

Prject Magenta and my PFC driver both support AT on/off switching -- they do this by writing a 0 or 1 to the A/T Arm offset in FSUIPC. You can actually program Offset operations in FSUIPC's Button Assignments, but you really need the FSUIPC Programmers' Guide out of the SDK for a list of offsets and their functions. The offset of AT Arm is 0810 (hex) and 1 switches it on, 0 switches it off.

Regards

Pete

[stevens]

Thanks for the reply.

The programming "Autothrottle arm" for disconnecting the A/T works perfectly. It just toggles the switch on and off as I wish, but then another problem arises: In flight my autothrottle doen't work anymore. Even if I manually switch off the A/T button/switch, the thrust reverts to idle and does not follow my speed value set in the MCP/glareshield.

For reference, this effect happens on the SSTSIM Concorde. I did not test other aircraft.

Do you have a clue, why the autothrottle isn't working anymore?

Stefan

[Pete Dowson]

Even if I manually switch off the A/T button/switch, the thrust reverts to idle and does not follow my speed value set in the MCP/glareshield.

When you re-arm the A/T do you also then re-enable the appropriate thrust control mode in the A/P (IAS/Mach Speed for instance)? If you disconnect the autothrottle the speed modes turn off too.

For reference, this effect happens on the SSTSIM Concorde. I did not test other aircraft.

Always test default aircraft first. I couldn't possibly hazard any guess as to how add-on aircraft behave. You'd need to check with their documentation.

Pete

[stevens]

Pete,

I will check and will report on that.

Stefan

[stevens]

Ok, I tested it and you are right. Concorde has a different method to switch on the A/T on the overhead panel. I missed that. I could have saved time if I would have tested it with default aircraft! I learned something more!

BTW, the reason why I said it would be perfect to have the A/T disconnected when having idle thrust (or more precisely when having the thrustlevers at idle- big difference!) relates to the Airbus. The Airbus has two different methods of disconneting A/T. First the disconnect buttons on the side of each thrustlever and when having the thrustlevers at idle for more than 1 second disconnects the A/T as well.

This is quite different to Boeing, where you can move the levers and override the commanded angle. There it wouldn't make sense, I agree with you. But Airbus has no movable Thrustlever. They are in detents and pulling the levers idle is clearly the intention to disconnect A/T.

Anyway, problem solved, I am happy. Thank you very much for your help and sorry for trouble!

Regards,

Stefan