TagSea-Tac Airport(1855)

This 1992 study compares three planning reports on Sea-Tac Airport's future capacity and delays: the 1988 Airspace Update Study, the 1992 Terminal Development Plan, and the 1991 Enhancement Plan. The reports differ significantly in their passenger and flight operation projections for the year 2000, and show striking discrepancies in delay estimates — with the Enhancement Plan projecting delay hours more than five times higher than the Airspace Update Study. The document also outlines proposed solutions to reduce delays, including new runway construction, airspace conflict resolution with nearby Boeing Field, and improved approach procedures.

A 1992 position statement argues that Seattle-Tacoma International Airport (Sea-Tac) has reached its operational, economic, and environmental capacity and should be capped at a maximum of 380,000 operations per year with no third runway authorized. The document contends that noise impacts on surrounding communities are severely underestimated, that a third runway would make no operational or economic sense, and that alternatives such as demand management, use of existing regional airports, and improved transportation systems should be pursued instead.

In this 1992 letter, acoustics expert James D. Chalupník explains to attorney Richard Aramburu how aircraft noise near Seattle's Sea-Tac Airport is measured and rated, focusing on the appropriateness of the Ldn metric and the data used in the FAA's Integrated Noise Model (INM). He outlines the key physical properties of noise—intensity, frequency distribution, and fluctuation over time—and describes how various weighting schemes, particularly the A-weighting (dBA) scale, are used to approximate human perception of loudness and annoyance. The letter also notes the limitations of simpler metrics and introduces more sophisticated rating methods such as Stevens' Loudness Level and Perceived Noise Level for evaluating aircraft noise.

The CASE Group (Citizens' Alternatives to Sea-Tac Expansion) was formed in 1987 to oppose the Port of Seattle's plans to add a third runway at Sea-Tac Airport, gathering over 4,600 protest signatures and prompting the King County Council to pass a resolution against the expansion. The coalition organized public hearings, lobbied Port Commissioners, and circulated petitions urging state officials to reject expansion recommendations in favor of building a new regional airport away from densely populated areas. Their core argument was that alternatives to Sea-Tac expansion represented sounder economic and environmental choices for the Central and South Puget Sound region.

These two Port of Seattle Flight Track Sample maps compare jet aircraft arrival and departure patterns at Seattle-Tacoma International Airport (SEA) under south flow conditions, one from March 22, 1989 (pre-4 Post) and one from March 31, 1991 (4 Post). Both charts plot all jet flight tracks between approximately 4:30–24:00 and 6:00–22:00 respectively, showing how flight paths over the Seattle region shifted between the two periods. The maps are annotated to highlight southbound departures and arrivals over Seattle, serving as visual evidence for noise impact analysis related to airport runway and procedure policy changes.

The Seattle-Tacoma International Airport Noise Budget, effective January 1, 1991, is a formal agreement designed to limit and gradually reduce overall aircraft noise levels at Sea-Tac Airport. It establishes a system of noise allocations assigned to individual passenger and cargo carriers, measured through defined noise exposure levels, with limits enforced on both a quarterly and annual basis. The agreement outlines key definitions and rules governing how noise is measured, allocated, and managed, including provisions for new entrants, international carriers, and government aircraft.