MHFC: NextGen Enroute Delays & Noise Impacts over Vashon Island

An incredible airshow: Michael Huerta’s Flying Circus.

20160408.. Michael Huerta's Flying CircusIn service to the airlines, FAA has carefully worked to bypass environmental review procedures while also embarking on a scheme to abandon wholesale decades worth of noise mitigation procedures. In their effort to increase ‘throughput’, turns are being made lower and closer to the airports, for both departures and arrivals. This would reduce fuel consumption by a small amount, but the savings are routinely more than lost when excessive airline scheduling necessitates that ATC must issue delay turns (even entire delay loops) during the enroute/cruise portion of the flight.

It is really a circus. ATCs work harder, and pilots also work harder. More delays are incurred, all so that FAA can justify increasing the repetitive-noise-pattern impacts on neighborhoods that previously had no aviation noise issues.

This Analysis looks at how NextGen is destroying quality of life for residents of Vashon Island, west of SeaTac [KSEA]. As shown in the map below, with FAA’s NextGen redesign of the Seattle airspace, ATC is compressing small planes to fly lower in corridors crossing east-west over KSEA (specifically, note the magenta arrows and magenta text boxes). This is to accommodate lower (and heavier) arrival flows on north-south downwind legs roughly 6-miles west of SeaTac (over the island’s eastern half). KSEA.20160512.. portion of VFR sectional focused on S ARR flow impacts Vashon level-offsOn a beautiful clear day (May 12, 2016), KSEA was landing south. In a south flow, all arrivals from California/Oregon are aligned northbound on a published RNAV route over the east half of Vashon Island. Thus, Vashon Island residents become subjected to the noise of one flight after another. Problematically, with the NextGen changes, this noise impact pattern is repeated all day long and all night long.

A scrollable PDF of the Analysis is presented below. Note that the Analysis also looks at how NextGen is being oversold and consistently fails to deliver on the ‘benefits’ claimed by FAA and others. In this example, every KSEA arrival from California was turned early after taking off, and then given a direct flight to the KSEA arrival fix at Battle Ground, just north of Portland. But then, once enroute, ATC issued significant delays to each arrival, eliminating all time and fuel savings benefits of the NextGen departure procedures. These delays were necessitated by the excessive arrival flows that happen at hub airports. In this example, KSEA is a major hub used by both Delta (including Compass, or CPZ) and Alaska (including Horizon).


If FAA chose to, they could substantially mitigate these Vashon Island noise impacts. Notably, a natural descent corridor exists a few miles to the east, over Puget Sound. NextGen technologies would easily allow FAA to create a simple customized noise-mitigation arrival route over the middle water area. But, unfortunately, it appears FAA is set on cookie-cutter downwind legs.