Preliminary Evaluation of Flight Delay Propagation through an Airline Schedule

Airline schedules are based on the carefully-planned use of resources, airports, planes, crews, etc., to provide passengers with on-time arrivals. When airport capacity is reduced below demand, the schedule can no longer be maintained and arrivals are delayed. Once initial delays take place, additional downstream delays frequently follow because crews and planes are not available for these later flights. The present analysis develops the concept of a delay multiplier to quantify this propagation, and evaluates the proposed metric using American Airlines’ data. The delay multiplier appears to provide a relatively simple measure of how delay impacts an airline’s schedule and thus provide an input to airline and FAA decisions, and thus help minimize the system impact of initial delays. Additional analyses to better understand how the delay multiplier changes with arrival airport and differences in airline connection models are warranted.