Note: This procedure requires editing a game file; creating a backup copy of the file before proceeding is recommended. Also, have the game patched to the latest version. Use a text editor to edit the "buildings" file in the "\program files\global star software\airport tycoon 3\data\db" directory. Change the value before the word BUILD in each line to 0. Also, change the value after the word MONTHLYCOST to 0.