It depends on what FS your using.
For FS2004: You'll need the 'Aired' utility installed. If you don't have it,
get v1.42 here(SimV), or Google for 'aired 1.52' for the latest version. Either will work. Install and run Aired and open the *.air file for the aircraft. Find line 105
105 *Aircraft Type= 0 <--the aircraft is 'flyable' and in the select aircraft window
105 *Aircraft Type=2 <--ai only, not in the select aircraft window.
For FSX: just add a panel folder with a panel.cfg file. Can be any panel, doesn't have to 'match' the aircraft, in fact the panel.cfg can be an 'empty' file.
Dave
At that time [1909] the chief engineer was almost always the chief test pilot as well. That had the fortunate result of eliminating poor engineering early in aviation. Igor Sikorsky
I intend to live forever....so far, so good. Steven Wright
You know....you can just rip up a to-do list.