You can't get a plane in this game
The only plane that is available in Vice City is the Skimmer (which is a plane that floats on water). After you complete the mission called "Shakedown" Vercetti Mission, you have the ability to buy...
in aeroport but you can't drive it
tr,tr ,sq ,ci ,x ,l1 ,l1 ,dwn ,up
There is no cheat for planes in vice city neither can you get one.