I looked a little more into x-plane

The X-plugin data interface data items are listed at.
http://www.xsquawkbox.net/xpsdk/docs/DataRefs.html

search for fside_plug_acf
Appears to be 6 data items for extra plugin provided 3d force and 3d moment.

The simulator also include a builtin winch launch system.
Not sure what the model for the winch power curve is, but the parameters controlling it appear to be at /sim/world/winch in the same file.