COMMISSION 
AGENDA MEMORANDUM                        Item No.          3c 
BRIEFING ITEM                            Date of Meeting       April 25, 2017 
DATE:     March 7, 2017 (Memo revised April 19, 2017) 
TO:        Dave Soike, Interim Chief Executive Officer 
FROM:    Elizabeth Leavitt, Senior Director, Environment and Sustainability 
Arlyn Purcell, Director Aviation Environmental Services 
Stan Shepherd, Manager Airport Noise Programs 
SUBJECT:  Seattle-Tacoma International Airport Flight Track and NextGen Briefing 
EXECUTIVE SUMMARY 
Today's briefing will consist of an overview of NextGen presented by David Suomi, the Deputy
Regional Administrator of the FAA's Northwest Mountain Region. Mr. Suomi will speak on the
implementation of NextGen both throughout the National Airspace System (NAS) and
specifically the status at Sea-Tac. Stan Shepherd, Manager, Airport Noise Programs, will give an
overview of Sea-Tac's local flight procedures and noise programs. 
The Port continues to receive questions from the public regarding the benefits and impacts of
NextGen flight procedures on the local communities. This briefing is intended to help provide a
better understanding of increased air traffic at Sea-Tac Airport and the limited use of NextGen
flight procedures within our local airspace. 
BACKGROUND 
Flight track and noise abatement procedures have been in place at Sea-Tac Airport since 1990
when the Federal Aviation Administration (FAA) implemented the 4 post plan to safely and
efficiently funnel aircraft into and out of Sea-Tac Airport through 4 different quadrants of the
airspace.  Sea-Tac's jet aircraft noise abatement procedures mimic most of the 4 post plan
procedures with a goal of keeping aircraft over water and industrial areas whenever feasible.
Where there is no water or industrial options, corridors keep jet aircraft on a narrow path until
reaching defined distances and altitudes before turning.  Due to their relatively lower speed,
propeller aircraft do not follow noise abatement procedures and are turned after takeoff to
ensure safe separation from jets. 
Noise abatement procedures in place at Sea-Tac are designed to minimize the impact of aircraft
noise on the airport's surrounding communities. Other  noise-related programs the Port has
implemented include sound insulation of single-family homes and condominiums, as well as 
acquisition of residential property impacted by aircraft noise.   These programs must be 
approved by the FAA through their Part 150 regulation process that outlines steps airports must

Template revised September 22, 2016.

COMMISSION AGENDA  Briefing Item No. 3c                                  Page 2 of 2 
Meeting Date: April 25, 2017 
take to gain federal funding eligibility. Sea-Tac completed its last noise study in 2014 and is in
the implementation phase of the mitigation programs starting with the completion of the
earlier single-family residential sound insulation.  The Port also will continue its commitments
to the Highline School District to provide funding for sound mitigation to schools outlined in a
2002 Memorandum of Agreement between the School District, the FAA and the Port.  Each
school sound insulation project will be submitted for funding approval from the FAA. 
In 2008, Sea-Tac teamed up with Alaska Airlines and The Boeing Company to discuss ways of
reducing noise and emissions within the Puget Sound Region. As a result of those discussions
and preliminary work, the FAA developed the Greener Skies program, which consists of GPS
flight procedures known as Required Navigation Performance (RNP).  RNP relies upon GPS
satellite technology, rather than ground-based radar, to guide aircraft in a more precise flight
path, and it is one element of the FAA's comprehensive NextGen program. The goal of the
Greener Skies program is to increase the efficiency of flight tracks by bringing aircraft in from
west side approaches, over water as much as possible, using Optimized Profile Descent (OPD). 
A quieter, more fuel efficient approach, OPD allows the aircraft to utilize an idle engine setting
from high altitudes all the way to the runway. The RNP tracks were developed to shorten track
miles and minimize community overflights where possible. Although the FAA began using the
Greener Skies RNP in 2014, it has yet to be fully implemented due to flight procedure conflicts 
with aircraft that use the legacy Instrument Landing System (ILS).  Out of approximately 500
total arriving flights per day at Sea-Tac, roughly 200 flights use the RNP procedures to some
degree. On final approach, all aircraft, including those using RNP, ILS and Visual approaches use 
approximately a 3 degree descent, which is standard at U.S. airports. 
ATTACHMENTS TO THIS BRIEFING 
(1)   Port of Seattle presentation slides 
(2)   FAA presentation slides 
PREVIOUS COMMISSION ACTIONS OR BRIEFINGS 
February 21, 2012  Commission Briefing on Greener Skies Over Seattle 






Template revised September 22, 2016.