How FAA Hopes to Change the Airway Structure

FAA has outlined a concept for overhauling the current network of low- and high-altitude airways. The plan is part of the FAA’s initiative to move toward performance-based navigation (PBN). At present, the proposal is just that—it isn’t a formal program with full funding.

The presentation, given at the FAA’s Aeronautical Charting Forum meeting on October 28-30, is available as a PDF in my  Aviation Documents folder at OneDrive.

The guiding principles of the proposal are:

  • “Structure where structure is necessary and point-to-point where it is not.”
  • Route structure requirements will be based on factors such as traffic demand, airspace utilization, ATC task complexity, airspace access, and user operational efficiencies.
  • Ground based airways will be retained in areas of with poor radar coverage and in mountainous terrain.

Pilots of light aircraft are most concerned about low-altitude airways and routings, including the venerable victor airways and newer T-routes.

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Regarding T-routes, FAA hopes to publish low-altitude PBN ATS routes “precisely where needed to”:

  • Access rather than circumvent Class B/C airspace
  • Lower minimum altitudes in areas of high terrain to improve access and avoid icing
  • Circumvent Special Use Airspace in safe and optimal manner

The presentation includes an interesting slide that shows daily utilization of victor airways. The average for the top 81-100 low-altitude airways was just 3 operations (in FY2013).

The graphic below shows how V2, which runs east-west across the northern part of the US, was used in the last two fiscal years. Very few aircraft flew most segments of the airway.

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Note that the segment that crosses the Cascades east of Seattle (SEA-ELN) gets regular traffic. Other segments, such as MINNY-MKG across Lake Michigan, and legs near BUF, are also well-used, probably due to ATC requirements in these high-traffic areas.

The FAA notes that 80-90% of the aircraft flying the 20 most-used victor airways are already equipped to fly T-routes, which require an IFR-approved GPS.

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Given that so many aircraft are RNAV-capable, FAA notes that “Users file any combination of route segments, NAVAIDs, and  waypoints when not route restricted by ATC and automation.”

The proposal advocates retiring existing point-to-point navigation programs to give pilots more flexibility in planning and filing direct routes. FAA says it will work with users to create a network of optimally placed waypoints. When specific routes are required, the plan would expand the network of ATC IFR preferred routes, which would not necessarily follow existing airways. Point-to-point navigation would available elsewhere.

The new routes outlines in the plan would also:

  • Increase the number of parallel route options through high density airspace
  • Reduce separation between centerlines of published routes to 8 nm
  • Circumnavigate Special Activity Airspace

For example, the program noted that T-319 passes directly over KATL, giving controllers a straightforward way to route aircraft through the Atlanta Class B airspace.

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