TagFAA(684)

This 1990 Final Environmental Assessment, prepared by the FAA's Air Traffic Division in Seattle, evaluates proposed changes to arrival and departure flight routes at Seattle-Tacoma International Airport. The document was signed by Air Traffic Division Manager Temple H. Johnson, Jr. on March 27, 1990, and examines the potential environmental impacts of rerouting aircraft traffic in and out of Sea-Tac. It serves as an official federal record relevant to noise and environmental policy affecting communities around the airport.

This 1990 FAA document explains why the Day Night Average Sound Level (DNL) was chosen as the standard metric for measuring airport noise. DNL averages noise exposure over a full 24-hour period, applying a penalty for nighttime flights, and has been adopted by multiple federal agencies—including the EPA, DOT, HUD, and DOD—as the most reliable way to assess how aircraft noise affects surrounding communities. The FAA formally incorporated DNL into federal regulation through FAR Part 150, Airport Noise Compatibility Planning, in 1981.

Since 1982, Seattle-Tacoma Airport (Sea-Tac) has received 13 federal AIP grants totaling over $50 million to acquire approximately 750 noise-impacted land parcels near the airport. In addition, four federal grants totaling over $7 million have funded a noise insulation program that has treated 323 homes, with further funding of $3.2 million per year requested to insulate roughly 175 additional houses annually over the next four years.

This 1990 Final Environmental Assessment, published by the U.S. Department of Transportation's Federal Aviation Administration, examines proposed changes to air traffic arrival and departure routes at Seattle-Tacoma International Airport. Volume II of the document compiles public comments received in response to the Draft Environmental Assessment, reflecting community input on how the proposed route changes could affect noise and other environmental conditions in the Seattle, Washington area.

This 1989 draft Environmental Assessment, prepared by the FAA's Air Traffic Division, evaluates proposed changes to arrival and departure flight routes at Seattle-Tacoma International Airport. The changes aimed to reduce air traffic congestion and improve airspace efficiency, particularly during peak demand periods when south-arrival capacity (42 aircraft/hour) lagged significantly behind north-arrival capacity (56 aircraft/hour). The inefficiency was linked to a requirement routing turbojet aircraft through Elliott Bay, a legacy of noise abatement agreements with local governments and the Port of Seattle dating back to 1970.

This 1989 FAA draft Environmental Assessment examines proposed changes to arrival and departure flight routes at Seattle-Tacoma International Airport, aimed at reducing air traffic congestion and improving airspace efficiency. The document identifies a key inefficiency: during good weather and peak demand, south-landing capacity (42 aircraft/hour) was significantly lower than north-landing capacity (56 aircraft/hour), largely due to a requirement routing turbojet aircraft through Elliott Bay. The assessment traces the issue back to noise abatement procedures established since 1970 that prioritized limiting jet overflights in certain Seattle metropolitan areas over operational efficiency.

The 1989 Airport Capacity Enhancement Plan, produced by the FAA and U.S. Department of Transportation, outlines efforts to increase airport capacity and efficiency across the U.S. air system without compromising passenger safety or the environment. It identifies causes of capacity and delay problems, projects the impact of increased air traffic over the following decade, and describes planned projects covering airport development, airspace procedures, new equipment, and capacity planning studies. Note: this document addresses national airport capacity issues broadly and does not focus specifically on Sea-Tac Airport or local noise policy.

In September 1988, the Port of Seattle Port Commission passed Resolution No. 3035, authorizing the acceptance of a Federal Aviation Administration grant (AIP Project No. 3-53-0062-19) to fund development work at Sea-Tac International Airport. The project included construction of Taxiway A-3/4, installation of an electrical duct bank and broadramp centerline lights, and widening of Taxiways B-2 and A-1. The resolution directed the Executive Director to sign the grant agreement on the Port's behalf, provided it was reviewed and approved by the Aviation Division and Legal Department.