ATC Speed Assignments In The U.S. Are Tied To NextGen


ATC Speed Assignments in the U.S. Are Tied to NextGen

Michael Prather | - 10/17/2016
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Featured, Planning and Operating

Up to date on the method of receiving speed assignments within the U.S.? A new measure has been introduced that is changing the way pilots receive this information…

Since the end of August, pilots been hearing some new terminology while receiving arrival procedures into airports within the United States. Pilots can now expect speed assignments in 5-kt increments instead of what has been the standard 10-kt assignment. Above FL240, these assignments may be given in Mach 0.01 increments for turbojet aircraft with Mach meters. This is all a part of the United States’ move toward the NextGen airspace redesign that is in progress.

Although it may seem very unusual to hear a speed assignment of 195-kts, this is all part of an effort to move from a distance-based separation (miles-in-trail) to a time-based separation, or metering of aircraft. This is a part of the overall move to a more performance-based navigation (PBN) system. Rich Boll, chairman of the ATC, Airspace and Flight Technologies Working Group of the NBAA Access Committee, has commented on this. According to him, as the FAA move toward greater use of performance-based navigation processes, this is a tool that can precisely align the time an aircraft passes over a certain fix, and allows controllers to better tie STAR procedures into the approach to final.

Before this new procedure was in place, the pilot would begin getting vectors as much as five to ten miles (8 to 16 km) out before they were turned into the final approach to keep the distance separations in place from other landing traffic. However, with the ability to do a more time-based separation, a more direct routing can be given to the airport. Even though the pilot may begin slowing down at points further away from the airport, with the more direct routing, the overall timing into the airport will be improved, which will create more on-time arrivals for all aircraft.

Currently, these changes don’t apply to arrivals. However, shortly, this will expand and become a part of the arrival procedures even further out from the airport as the NextGen initiative expands throughout the airspace. Even further in the future, these new assignments will likely be given on departure procedures as well.

The NextGen airspace redesign is happening in stages and will take up to the year 2025 to complete. This is just one of the many stages to help get the U.S. airspace transformed from a radar-based system to one that is controlled by satellites and GPS technology. Overall, this will help all operators within the airspace save time and fuel, which ultimately saves money for everyone involved. This improved airspace will also be better for the controllers, who will ultimately be manning a much busier, but more organized airspace.
The current 5-kt speed assignment was issued by a notice to the controllers from the FAA in FAA Order JO 7110.65, paragraph 5-7-1, Speed Adjustments, and can also be found in Section 4-4-12 of the Aeronautical Information Manual (AIM).