Airspace Flow Programs (AFPs)

Managing the nation’s skies is a challenging duty. The Federal Aviation Administration (FAA) has the task of managing flights so that they operate in a safe and efficient way. One component of this management is air traffic control, which is responsible for dealing with individual flights and making sure that they speed up or turn or do whatever is necessary to maintain the desired separation between planes. The other component is traffic flow management (TFM), which aggregates flights so that congestion is minimized.

The FAA has long had TFM tools to deal with particular types of congestion. For example, when there is congestion because of bad weather at an airport, the FAA can issue a ground delay program to control arrivals so that they reach the airport at the rate the airport can handle. For small-scale weather disturbances, like thunderstorms, the FAA can reroute flights around the weather.

Prior to 2006, however, the FAA did not have a tool that dealt with large-scale weather systems that covered a large part of the country.The FAA/Metron Aviation/Volpe Center in 2005 and 2006 created and deployed a tool called Airspace Flow Programs (AFPs) to deal with these large-scale weather problems.

Issuing and executing an AFP typically consists of the following steps:

• An FAA traffic manager selects the area that is affected by the weather. Managers can filter the flights that go through this area, for example, choosing only flights going from west to east.
• An FAA traffic manager chooses the rate at which flights may enter the area. That is, even during bad weather, some flights, although far fewer than usual, are able to find their way through.
• AFP software calculates the times that flights should depart so that they arrive at the area of bad weather at the desired rate.
• These controlled departure times are distributed.Airlines and other flight operators are informed of the time that each flight should depart.The system also informs FAA personnel in control towers when flights should be allowed to take off.
• As the day unfolds, the FAA can revise the AFP as necessary to reflect unexpected developments in weather or demand.
• The flight operators can, if desired, reroute flights around the bad weather; that is, they are allowed to take the longer flying time instead of the departure delay if they choose.

In this way, decision making is distributed among the FAA and the flight operators, avoiding undue congestion in a controlled way so that the disruption to efficient operations is minimized.

In 2006 and 2007, the FAA used AFPs on 43 days. The FAA calculates that the total savings in cost to the flight operators was about $118 million.The total cost of deploying AFPs, including the operations research analysis, software development, working with the users to fine-tune the concept, and preparing the procedures and training, was about $5 million.

Video of Federal Aviation Administration 2008 Edelman Finalist Presentation