PORT OF SEATTLE 
MEMORANDUM 

COMMISSION AGENDA               Item No.      7a 
STAFF BRIEFING 
Date of Meeting    November 24, 2015 
DATE:    October 30, 2015 
TO:     Ted Fick, Chief Executive Officer 
FROM:    Michael Ehl, Director, Airport Operations 
SUBJECT:  Flight Corridor Safety Obstruction Management Briefing 
SYNOPSIS 
Federal Aviation Administration (FAA) requires airport operators to protect flight
operations into and out of the airport and assure that objects obstructing approach and
departure areas are removed. Approximately 1,600 obstructions have been identified at
and around Seattle-Tacoma International Airport (airport), consisting of trees and other
vegetation, which must be removed to maintain compliance with regulatory requirements. 
To support effective communication and transparency with communities affected by the
Flight Corridor Safety Obstruction Management Program, a comprehensive outreach and
communication strategy has been developed.
BACKGROUND 
Obstructions are any objects penetrating FAA designated approach and departure paths at
or around an airport. Obstruction studies and the related publication of obstruction charts
were completed every ten years by the FAA until approximately 1994. In preparing for
the activation of the Third Runway, the FAA produced obstruction analyses in 2005
which led to the removal of trees in 2006-2008. An aerial obstruction analysis was
conducted by the Port in 2015 identifying approximately 1,600 obstructions, consisting of
trees and other vegetation. These trees have grown to the point where they are
considered obstructions by FAA. As trees surrounding the airport continue to mature, it is
likely that additional trees will penetrate the approach and departure surfaces and become 
obstructions. The number of trees designated as obstructions and therefore requiring
removal must be verified as part of an ongoing program for obstruction identification and
removal. 
Similar obstructions in approach and departure areas near the airport have been removed
in the past; however, these efforts have been relatively minor in nature. Work is

Template revised May 30, 2013.

COMMISSION AGENDA 
Ted Fick, Chief Executive Officer 
October 30, 2015 
Page 2 of 3 
underway to develop a comprehensive Flight Corridor Safety Obstruction Management 
Plan, which will occur in several phases, spanning multiple years. Implementation will
be based on a phased delivery approach which will generally occur in the following
sequence: 
1.  Port-Owned Property (on and off of airport) 
2.  Publicly-Owned Properties (Burien, Des Moines, SeaTac, Washington State
Department of Transportation (WSDOT), Seattle Public Utilities and Highline
Public Schools) and Commercial Properties 
3.  Residential Properties 
The Port will conduct an environmental review process for the removal of obstructions to
aircraft operations, which includes the opportunity for community input. This
environmental review in accordance with federal, state, and local requirements will
ensure that the Port evaluates alternatives and potential environmental impacts of the
program. A revegetation plan will be developed to minimize future obstructions, identify
planting requirements, and consider various approaches to replanting. Environmental
review and permitting associated with adjacent jurisdictions will be included in the
program.
To support effective communication and transparency with communities affected by the
Flight Corridor Safety Obstruction Management Program, a comprehensive outreach and
communication strategy has been developed. The cities of SeaTac, Burien and Des
Moines, Highline Public Schools, Seattle Public Utilities and WSDOT will be involved in
the communication strategy, engagement process, and finalization of the Flight Corridor
Safety Obstruction Management Plan.
Justification for this program falls under the following categories: 
1.  Federal Requirements for Airport Operators to Control Obstructions 
a.  Federal Aviation Regulation (FAR) Part 139, Certification of Airports 
b.  Advisory Circular (AC) AC 150/5300.13A change 1, Maintenance of obstacle
clearance surfaces 
c.  Grant Assurance 20 "Hazard Removal and Mitigation" 
d.  Grant Assurance 21 "Compatible Land Use" 
2.  State Requirement for Airport Operators to Control Obstructions
a.  RCW 14.12.020 "Airport hazards contrary to public interest" 
3.   Airport's Strategic Goals and Objectives 
a.  Strategic Goal No. 1, Operate a world-class international airport by: Ensuring
safe and secure operations 
ATTACHMENTS TO THIS BRIEFING 
PowerPoint presentation

COMMISSION AGENDA 
Ted Fick, Chief Executive Officer 
October 30, 2015 
Page 3 of 3 
PREVIOUS COMMISSION ACTIONS OR BRIEFINGS 
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