Action Items

Late Night Noise Limitation Program

Description

Voluntary measure to reduce late night
(12:00 AM to 5:00 AM) noise by
incentivizing air carriers to fly at less
noise sensitive hours or transition to
quieter aircraft
• Ongoing outreach with air carriers
about possible late night schedule
and aircraft fleet changes including
meetings with carriers with the most
noise exceedances
• Established noise thresholds that
identify aircraft exceeding noise
thresholds during the late
night hours
• Late night noise threshold
observance tracked and reported
out on a quarterly basis and
publicized as part of the Fly Quiet
Program
Reduction of aircraft noise during the
late night hours

Components

Change

Key
Responsible
Parties
Status
Update

Port of Seattle, airlines and air cargo
carriers
COMPLETE - Program commenced in
July 2019 with regular reporting each
quarter to external audiences. In 2021,
the program achieved its first significant
success when EVA Air made the switch
to a quieter aircraft during the late night
hours. Since the program’ inception,
Port staff have met with the following
air carriers to discuss their late night
noise exceedances: EVA Air,
ATI/Amazon, China Airlines Cargo,
FedEx Express and Korean Air Cargo.

SEA Stakeholder Advisory Round Table (StART)
Aviation Noise Working Group
Aviation Near-term Noise Action Agenda Summary (as of 2/23)
Runway Use Program
Glide Slope Adjustment
Ground Noise Study

Item No. 11a. attach 1
Meeting Date: March 28, 2023
Discouraging Reverse
Thrust
When conditions are right,
discourage overuse of
reverse thrust to
deaccelerate aircraft

Encouraging Rolling
Takeoffs
When conditions are
right, promote rolling
takeoffs

Noise Comment
Reporting
Provide up-to-date,
accessible information on
noise complaints and
comments submitted by
the public
Confirm there is a
Monthly statistic and
measurable noise
heat map reports posted
difference of instituting a on Port website detailing
rolling takeoff versus a
totals and trends by city,
traditional takeoff.
zip code and subject
Traditional takeoffs were matter. Regular updates
identified as a source of
regarding noise complaint
noise in the Ground Noise data provided at StART
Study.
meetings.

Revise the current informal
Runway Use Program to
minimize use of the Third
Runway during the late night
(12:00 AM to 5:00 AM)
Updated language for:
• Third Runway
daytime/evening runway
usage
• Third Runway late night
runway usage

Raise Runway 34R’s
glideslope to lessen aircraft
approach noise

Analyze airfield ground
noise sources and
identify potential
mitigation measures

Considered various
strategies and timelines for
raising Runway 34R’s 2.75
degrees glideslope and
settled on plan to
permanently relocate 34R’s
navigational aids and
pursue a 3.0 degrees
glideslope with the FAA

Major ground noise
sources identified in the
study:
• Stop and go aircraft
sequencing/queuing
• Traditional takeoffs
• Reverse thrust
• Auxiliary Power Unit
(APU) use
• Engine maintenance
run-ups
• Dual engine taxiing

Reverse thrust was
identified as a source of
noise in the Ground Noise
Study

Reduction of aircraft noise
for Third Runway adjacent
communities and
communities underneath
the Third Runway’s
flightpath
Port of Seattle and FAA

Potential reduction of
aircraft noise for
communities south of SEA

Reduction of aviation
noise for close-in
communities
surrounding SEA

Reduction of aircraft noise
for close-in airport
communities

Potential reduction of
aircraft noise for
communities close to the
runway ends

Transparent and
convenient information
on noise complaints and
comments submitted by
public

Port of Seattle and FAA

Port of Seattle, FAA, airlines
and air cargo carriers

IN PROCESS - The 34R glide
slope adjustment is
incorporated into a SEA
taxiway reconfiguration
project. Preliminary design
is complete.
Implementation is
contingent on the
Sustainable Airport Master
Plan’s (SAMP) finalization
and FAA approval.

Port of Seattle, FAA,
airlines and air cargo
carriers
IN PROCESS – Noise
monitoring conducted by
Port staff to evaluate
rolling takeoffs didn’t
produce usable data.
However, based upon
past results at a
comparable airport,
implementation was
recommended.
Voluntary SEA language
encouraging rolling
takeoffs in development.

Port of Seattle

COMPLETE - Implemented in
September 2019. Late night
operations on the Third
Runway dropped
dramatically from an
average of 12 nightly
landings pre-implementation
to an average of four nightly
landings in 2022. Usage
continues to be monitored
and details communicated at
StART meetings.

Port of Seattle, FAA,
airlines and air cargo
carriers
COMPLETE – After
regular check-ins with
StART’s Aviation Noise
Working Group, the
consultants completed
the study in May 2022.
The study identified
several potential
mitigation measures that
the working group is
investigating.

COMPLETE – Updated SEA
voluntary language
discouraging use of reverse
thrust at all times and
beyond what is necessary,
implemented in January
2023. Air carrier awareness
campaign to commence by
mid-2023.

COMPLETE – Monthly
reports began with June
2020.