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Performance Success Stories

Greener Skies Over Seattle = Greener Skies Over the USA

An aircraft flying toward the runway at Seattle-Tacoma International Airport using the classic route and three aircraft flying toward the runway using a new, curved route

Airports referenced in this story

NextGen Implementation Plan (PDF)

Improved Approaches and Low-Visibility Operations (IALVO)
Outlines ways to increase access and flexibility for approach operations through a combination of procedural changes, improved aircraft capabilities and improved precision approach guidance.
Performance Based Navigation (PBN)
Addresses ways to leverage emerging technologies, such as satellite-based Area Navigation and Required Navigation Performance, to improve access and flexibility for point-to-point operations.

Shortly after 10 p.m. on the evening of June 11, Alaska Airlines flight 505 from Los Angeles landed at Seattle-Tacoma International Airport. Unknown to the passengers on board, the pilots approached the airport using a satellite-based navigation arrival procedure that may save operators more than two million gallons of fuel a year, which means a significant reduction in aircraft exhaust emissions.

Flight 505 was the first passenger flight in the Greener Skies Over Seattle initiative, a collaborative project between the FAA, airlines, the Port of Seattle, and Boeing Corporation that will leave Seattle's skies quieter and greener. The FAA will add 27 new procedures, expanding the use of Optimized Profile Descents (where the airplane essentially glides in idle to the runway threshold), Area Navigation (RNAV) arrivals (which are GPS-guided arrivals) and Required Navigation Performance (RNP) approaches (which take RNAV to an additional level of precision). These procedures will be available to any properly equipped aircraft next spring.

Alaska Airlines estimates the Greener Skies procedures will cut fuel consumption by 2.1 million gallons annually and reduce carbon emissions by 22,000 metric tons, the equivalent of taking 4,100 cars off the road every year. In addition, they will reduce overflight noise exposure for an estimated 750,000 people living within the affected flight corridor.

A goal of Greener Skies is to prove that satellite-based navigation approaches can be flown using the same separation standards as procedures using ground-based instrument landing systems have today. The trials seek to determine that a curved RNP approach to one runway is so precise and predictable, that when it is flown next to another aircraft that is approaching a parallel runway, it merits the same separation standard as two straight-in parallel approaches.

The Greener Skies flight trials will verify air traffic control processes, procedures and traffic flow management. Once the environmental analysis, approvals and safety cases are assessed, the FAA will update air traffic controller and aircraft operator rule books with the modified separation standards for use by all qualified operators and in all weather conditions.

When Greener Skies is completed, the FAA will have a template for how to implement these kinds of airspace improvements across the country.

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