After nearly a year of planning, the FAA is launching a new en route traffic-management tool called airspace flow programs (AFP). The goal of the AFP is to shift away from using ground delays at destination airports not affected by en route weather as a tool to manage traffic demand during severe weather.
In the AFP system, flights planned through airspace constrained by severe weather will have to endure delays or avoid that airspace. These delays are shared equally by aircraft filing to fly through that airspace, and no segment of aviation is favored by the FAA system. “Everyone gets an equitable share of the delay,” said Jo Damato, NBAA’s senior manager of air traffic operations and a member of the FAA/industry AFP work group that helped develop the new procedures.
The problem with the existing ground delay program used to manage heavy air traffic is that it creates congestion at airports but doesn’t slow demand in constrained airspace where weather is forcing ground delays.
The initial AFP implementation, beginning May 1, covers traffic flying eastbound into the busy Northeast U.S. and includes six AFP scenarios. A scenario consists of a geographical boundary line usually where ATC centers meet, with altitude and arrival filters that further define the constrained airspace and typical weather problems that crop up in that area. AFP A04, for example, covers airspace from FL120 to FL600 on the western and southern boundary of Boston Center with arrivals into Washington and New York Centers. Weather that would trigger AFP A04 includes thunderstorms in the Ohio Valley.
There are an average of about 40 severe weather-avoidance plan days per year in the U.S., and the average annual delays due to weather add up to about 100,000 minutes, according to Damato. This means that there could be 40 or so AFP scenarios, although the FAA’s tools allow building scenarios for special occurrences, such as a glut of traffic heading to the Super Bowl or other traffic bottlenecks.
For pilots flying IFR above 12,000 feet, the AFP adds new procedures, but the reward is that delays should be spread fairly among aircraft trying to use airspace constrained by severe weather. Aircraft flying under, over or around an AFP to a destination free of weather problems should not experience delays due to the AFP.
In practical terms, the FAA implements an AFP when severe weather causes or is forecast to cause constraints in the en route system. By identifying flights that are filed to enter the constrained area, controllers can issue expect departure clearance times (EDCT) to these flights to meter demand through that area. As weather and traffic flows change, controllers can adjust delays to match the capacity of the constrained airspace.
For operators, instead of arriving at the airport, loading the passengers, then calling clearance delivery or ground control and learning that there is a one-hour delay, the AFP helps by letting crews check AFP status hours before takeoff. If there is a delay, the pilots will learn about it earlier and can warn passengers before they head to the airport. Pilots also have new alternatives; they can plan flight paths around AFP areas and at least get in the air so passengers can do their work en route instead of hanging around an FBO lobby. “Now,” said Damato, “you can get the information [on delays] on your own once your flight plan is in the system.”
According to the concept paper, “If an AFP is issued and your flight is included, the pilot will receive an EDCT. Meeting the assigned departure time is important because it allows traffic managers to properly meter flights through the constrained area being controlled by the AFP.”
If there is a possibility that an AFP has been issued, pilots will need to check the FAA’s National Airspace System Status Web site (www.fly.faa.gov/ois/) during flight planning and obtain an EDCT before takeoff. There is a five-minute window before and after the EDCT during which a flight can depart.
Before the launch of the Northeast AFP on May 1, the FAA will issue an advisory circular explaining the procedures. NBAA will also publish guidance, and this material will all be available at www.nbaa.org/afp.