The Airport Madness series is a collection of air traffic control simulations. Airport Madness 1 is a game set in an airport with 2 runways in an stretched X formation. Airport Madness 2 is set in two airports with different configurations. Airport Madness 3 is based in 2 different airports, with 2 main levels for each. Both of the airports have 2 different runway approches. Each game has a level system that starts with 1 runway, and as each level passes, a new element is added to the airport, for example, you might get a new runway, or you might get bad weather.
Source: Wikipedia, "Airport Madness", available under the CC-BY-SA License.