TagPart 150(262)

The Integrated Noise Model (INM), developed by ATAC Corporation for the FAA, was the standard computer tool used to assess aircraft noise impacts near airports like Sea-Tac, calculating noise exposure contours and predicted sound levels at sensitive locations such as schools and hospitals. It was required for airport noise compatibility planning under FAR Part 150 and environmental reviews under the National Environmental Policy Act until it was replaced by the Aviation Environmental Design Tool (AEDT) in May 2015. Though no longer valid for regulatory use in the U.S., the INM was used by over 1,000 users in 65 countries to evaluate the noise effects of runway changes, flight routing, air traffic procedures, and shifts in aircraft fleet mix.

This document is the FAA's Record of Approval for Seattle-Tacoma International Airport's Noise Compatibility Program, which outlines measures to reduce aircraft noise and manage land use around the airport. It covers both new and updated measures, including voluntary rescheduling of nighttime flights, preferential runway use during nighttime hours, and a Fly Quiet Program to encourage airlines to follow noise abatement procedures. The FAA approved most measures as continuations of previously approved programs dating back to 1985, while disapproving the engine maintenance run-up regulations.

Former King County International Airport (BFI) Noise Officer Sharyn Parker's prepared notes for a GAO interview outline significant concerns about FAA regulatory failures and Sea-Tac Airport's inadequate noise mitigation practices in the Seattle region. Parker argues that the FAA has consistently failed to require Sea-Tac to update noise exposure maps, enforce timely sound mitigation programs, or conduct meaningful public outreach — particularly for minority communities disproportionately affected by flight path changes like the Greener Skies/RNP initiative. The notes also highlight contradictions between Sea-Tac's deliberately low flight-operation projections in its Part 150 noise studies and the far higher growth figures used in its capital development plans.

This document is a review by ABCx2 of a Port of Seattle presentation to the city of Burien regarding the Sea-Tac Airport Master Plan (SAMP) Environmental Impact Statement. It raises concerns about the Port's decision to limit its environmental review of airport impacts to 2018 rather than 2012, questions whether significant construction growth and flight increases during that period were properly analyzed under federal (NEPA) and state (SEPA) environmental law, and challenges the Port's characterization of the FAR Part 150 noise abatement process as purely voluntary. The document also examines potential consequences if the Port fails to meet noise mitigation commitments tied to federal funding.

Local communities surrounding Seattle-Tacoma International Airport are demanding accountability from the Port of Seattle (POS) regarding its compliance with FAA Part 150 noise mitigation measures, some dating back to 1985. The document raises detailed questions about ten specific program elements — including voluntary flight rescheduling, engine run-up restrictions, noise abatement corridors, the Fly Quiet Program, and home sound insulation — asking for data on how consistently and effectively each measure has actually been implemented. Critics argue that despite decades of commitments, key noise reduction tools such as a Ground Run-Up Enclosure have been quietly dropped, while growing air traffic continues to harm residential neighborhoods and environmentally vulnerable populations.

The Quiet Skies Coalition challenges the FAA's Categorical Exclusion (CATEX) for new turboprop flight routes over Burien, Washington, arguing that the FAA's own noise analyses show significant increases in noise levels that exceed the agency's 1.5 dB DNL significance threshold — contradicting the FAA's claim of no environmental impact. The coalition contends that the FAA's reliance on an outdated 2013-2018 Sea-Tac Part 150 noise study, which failed to account for a 51% increase in airport operations, led to inaccurate noise assessments and improper use of a categorical exclusion. Community members and the City of Burien are urged to join legal and political efforts to challenge the FAA and Port of Seattle's authority over flight path decisions affecting residents from Shoreline to Federal Way.

A Burien Airport Committee member named Sharyn argues that Sea-Tac Airport's 2013 Part 150 noise study is dangerously outdated, as actual flight operations have been growing at roughly 9% per year — far outpacing the Port's own projections. Her analysis suggests Sea-Tac will reach its 2034 capacity forecast as early as 2020, meaning real noise impacts on surrounding communities like Seahurst are already well beyond what official noise maps show. She calls on the City of Burien to demand that the Port update its noise modeling immediately rather than waiting until after 2021.

Burien resident and former Boeing Field Noise Officer Sharyn Parker testified in support of HB 1683, arguing that the Port of Seattle deliberately understated Sea-Tac Airport's growth projections to avoid alarming nearby communities, while simultaneously planning a multi-billion dollar expansion — leaving residents exposed to increasing noise and emissions without adequate mitigation. She points to the Port's 2013-2018 Part 150 Noise Study becoming outdated just two years after approval, and a four-year delay in implementing approved sound insulation measures, as evidence of mismanagement and misleading communications. Parker and coalition members are calling for nighttime cargo flights to be offloaded to a new regional airport, contending that Sea-Tac has exhausted both its physical footprint and airspace capacity.