Noise Abatement Procedures Program

What are noise abatement procedures?

Noise Abatement Procedures are specific headings and altitudes for airplanes to fly in order to minimize noise impacts. Over the years, Noise Abatement Procedures were established by the Federal Aviation Administration (FAA) in cooperation with the Port and local communities. These procedures were designed to minimize jet overflights of residential neighborhoods by taking advantage of existing geographical and compatible land use conditions where possible. The Duwamish Industrial Area, Elliott Bay and Puget Sound provide some opportunities for aircraft to over-fly non-residential areas to the north of Sea-Tac Airport. The attached maps depict the Noise Abatement Procedures that are used to the maximum extent possible, air traffic conditions permitting. These maps are not intended to show actual flight tracks, only the corridors that are monitored for arrival and departure noise abatement procedures. These are not all the flight corridors, only those specifically related to noise.

North Flow

Click the North Flow map to expand it.

The North Flow map shows the corridors used when jet aircraft depart Sea-Tac to the north. The Initial Departure Corridor, shown in yellow, is intended to confine departing aircraft to the narrowest flight path possible. During the busier daytime hours, currently 6:00 a.m. to 10:00 p.m., aircraft will proceed from the Initial Departure Corridor into the Duwamish/Elliott Bay Corridor. This is the solid and hashed red colored area, from which aircraft may turn east or west. If traffic conditions allow when turning west, the airplanes are directed over Elliott Bay. Before starting their turn to the east, jets first fly eight nautical miles (NM) north and reach an altitude of 4,000 feet.

During the less busy nighttime hours, currently 10:00 p.m. to 6:00 a.m., jet aircraft are directed over the solid red colored area of the Duwamish/Elliott Bay Corridor and proceed west. Once out of Elliott Bay, the aircraft are turned north or south in the green colored areas, which are designated as the Puget Sound Departure. Jets remain over Puget Sound until reaching a specific altitude or distance from the Airport before turning east or west over the shoreline.

When flying north over the Sound, the aircraft must reach an altitude of 10,000 feet or a point 20 NM from the Airport before turning east. When turning west, aircraft must reach the 20 NM point at or above 10,000 feet before starting their turn.

When heading south, the aircraft must remain west of the shoreline until crossing the SEA 220-degree radial before starting a turn to the east. (This area is depicted by the straight edge portions of the dark green section on the map.)

Click for a map of sample Sea-Tac flight track patterns:

South Flow

Click the South Flow map to expand it.

The South Flow map shows corridors used by aircraft arriving from the north over the city of Seattle and departing to the south. The large orange colored area is the Puget Sound Arrival. The objective of this procedure is to have jet aircraft fly over or to the north of Elliott Bay. The yellow colored area south of the Airport is the Initial Departure Corridor, which is intended to confine departing jets to the narrowest flight path possible. Aircraft remain in this corridor until they are 5 NM from the Airport at an altitude of 3,000 feet. Once out of the initial departure corridor they can either continue south or start a turn to the east or west.

Click for a map of sample Sea-Tac flight track patterns:

Why do airplanes fly out of the corridors?

There are many reasons, sometimes beyond the airline's control, why a jet may fly out of the noise abatement corridors. These include traffic conflicts, weather, air traffic control directives, safety considerations, aircraft performance and pilot technique.

How are procedures monitored?

Although the Federal Aviation Administration has sole authority over aircraft in flight, the Port of Seattle, as operator of Sea-Tac Airport, has taken the lead responsibility for monitoring and reporting jet air traffic activities in terms of noise abatement. Data from the FAA's Automated Radar Terminal System (ARTS) is used to monitor aircraft performance while operating within established noise abatement corridors. A monthly summary is created and flight events are evaluated for each noise abatement procedure. The results pinpoint how successful air traffic controllers and pilots are at keeping flights within the noise abatement corridors.

The results are published in the form of a quarterly report. This program's success is dependent on cooperative efforts between the FAA and the airlines.

If you would like to be added to our mailing list, or need further information on Sea-Tac's noise abatement programs, please call (206) 433-5393 or Toll Free (800) 826-1147.