This applies to the 757 as well, however I'm not sure if it is the same IPC code.

I've noticed that the FSUIPC and P3D standard control for "Auto Throttle Arm" turns off the autothrottle arm switch in the aircraft.

However, this is not an appropriate way to disconnect the auto throttles for making a manual landing. We only turn off this switch during an abnormal situation- when directed by a checklist.

If you want to hand-fly (AP and A/T off), you'll actually click the small button on the side of the throttles- which will disconnect the A/T , and a second press will cancel the caution.

The way to accomplish this with a joystick button push is through a lua file. Place the below folder into your modules folder, or C:\Users\*name*\Documents\Prepar3D v4 Add-ons\FSUIPC6

Now you can assign a button on your hardware device to "Lua ATdisconnect" instead of trying to find the button with your mouse during a high workload time.

Copy the text below into a new text file, and save as "ATdisconnect.lua" - make sure the extension reads "lua"- and throw that in your FSUIPC folder.

ipc.writeLvar('L:P05_007_BUT',1)
ipc.sleep(500)
ipc.writeLvar('L:P05_007_BUT',0)