TagPBN(7)

A document explaining changes to aircraft arrival patterns at SeaTac airport around 2015, including the introduction of Performance Based Navigation (PBN) technology and lowered flight altitudes. The changes concentrated flight paths over Vashon Island in a narrow corridor, causing increased noise pollution for residents who chose to live there for its peaceful environment.

This document contains a structured set of interview questions developed for a GAO study (project 103933) examining how NextGen flight path changes have affected local communities through increased aviation noise. The questions are directed at community groups and cover topics including FAA outreach efforts before and after implementation, equity concerns, the drivers of noise complaints, and whether any flight path modifications were sought or made following implementation. It aims to assess how effectively the FAA communicated with and involved communities in performance-based navigation (PBN) decisions.

This 2021 presentation by aviation consultant Jim Allerdice examines 'dispersion' — the practice of intentionally varying flight paths so that aircraft noise is spread across a wider area rather than repeatedly concentrated over the same neighborhoods. It explores the tension between the FAA's preference for Performance-Based Navigation (PBN/RNAV), which promotes precise, repeatable flight paths for safety and efficiency, and the concerns of communities living under those concentrated flight corridors. The material is relevant to ongoing debates about how airports like Sea-Tac can balance operational efficiency with equitable distribution of aircraft noise impacts.

A 2019 U.S. Department of Transportation Inspector General report found that the FAA's Metroplex program—designed to modernize flight routes using satellite-based navigation in busy metropolitan areas—fell significantly short of its promised benefits, delivering only $31.1 million in annual savings compared to the $61.6 million minimum originally projected. The program also faced delays of up to four years, driven largely by community concerns about aircraft noise, which is directly relevant to ongoing noise issues around airports like Sea-Tac. Key obstacles such as unclear pilot-controller terminology and a slow procedure amendment process remained unresolved at the time of the report.

A 2013 U.S. Government Accountability Office report found that the FAA made limited progress in modernizing the air transportation system through its NextGen initiative, with ongoing challenges reducing expected benefits. The report highlights the FAA's Greener Skies project at Seattle-Tacoma International Airport, initiated by Alaska Airlines, which aimed to shorten flight paths and route aircraft over water to save fuel, but excluded certain eastern flight procedures due to community concerns about aviation noise. The report notes that the full benefits of new flight procedures depend heavily on how often airlines and pilots actually use them.