Open up the aircraft editor through the Start-Program Files-Microsoft Games, then open the a/c, select just the name of the aircraft (your aircraft/Tower Air) then go down to the ATC Info, specify the ATC Type (Aircraft Maker) then Model (A/C Model), save and go fly. 

If you want to organize your a/c by Company/Make/Model, you can also do so above in the Aircraft Info section above the ATC Info section.