Planes request to land or to take off.
They get to take off in the order their requests are made, but NO plane can take off until ALL planes in the air have landed. In the GUI below you can enter a plane's name and fuel amount if it is requesting a landing. We don't care about fuel levels for planes taking off. At any time you can request a Status Report of all planes in the air and on the ground and their correct order for landing and takeoff. Here are the files for your program.