There are frequently several different ways in which passengers may fly from any one point to any other in an airline network. Passengers may choose a nonstop flight, a flight using the most desirable type of aircraft, a flight departing or arriving at the most convenient time, and so on. It is therefore necessary for an airline to plan many months ahead to obtain a flight schedule that will best answer the needs and desires of the traveling public. The Passenger Allocation Model has been designed and developed to assist in this planning process. It allocates a forecast volume of passengers, traveling from any point in the system to any other point, to the various flight paths offered by a proposed schedule. Decision rules are used that quantify the effects of such factors as the frequency of all flights between the two points, the times of arrival and departure of each flight, the types of aircraft to be used, the types of flights (direct or connection) and the number of seats available. This paper describes the general structure of the model.