I want to know if there are any cheats in Pocket Planes as the maximum number of airports in a level thing is really annoying me to my wits end.
If by cheats you mean exploits, then there is at least one detailed by IGN:
WARNING: This cheat requires you to modify your phone's system clock. Follow the directions precisely in order to avoid file corruption.
To perform the cheat and speed up plane jobs, assign planes jobs and then close the app (double click the home button, then hold the app and tap the red circle). Enter the appropriate menu on your phone and move the clock ahead so that the planes in the Pocket Planes software will have had time to land. Remember that if you fail to close the software before updating the time, file corruption will follow. Be careful.