Item No.:              7a Supp 
Meeting Date:         November 24,2015 
Flight Corridor Safety
Obstruction Management 
Commission Briefing 
11/24/15

Why Obstruction Removal? 
FAA regulations and WA State law require
airports to identify and remove obstructions to
navigable airspace on and around the airport. 
Removal of obstructions helps to ensure safe
operation of aircraft takeoffs and landings.
This is not unusual - airports around the
country manage similar programs to protect
the safety of the flying public.
Ensuring safe, secure airport operations is our highest priority.

What are Obstructions? 
Obstructions on and around Sea-Tac Airport
consist mostly of trees (and other
vegetation). 
Preliminary analysis indicates the presence
of trees needing removal from properties in
Burien, SeaTac, Des Moines, Highline Public
Schools, WSDOT and Seattle Public Utilities
rights of way. 
An obstruction is any object affecting the safe and efficient use of navigable airspace.

Obstruction Example 



Trees penetrating approach surfaces are considered obstructions.

North Obstructions

South Obstructions

General Program Phases 
Based on a phased delivery approach which
will generally occur in the following
sequence: 
Phase One (2016):Port-owned property (on and
off of airport) 
Phase Two (2017):Publicly-owned and
commercial properties 
Phase Three (2018): Residential properties 
A phased approach provides time to plan and engage stakeholders.

Community Engagement 
Working with local jurisdictions to identify
obstruction locations and determine
removal/replacement requirements. 
Ongoing outreach and communication with
impacted cities and residents. 

Engaging stakeholders supports transparency and provides opportunities to provide input.

Next Steps 
Complete process to verify obstructions and
determine local jurisdiction removal and/or
replacement requirements. 
Comply with state, federal and local
environmental requirements. 
Obtain Commission authorization to advertise
and execute construction contract. 
Proceed with Phase One (2016) 
Proceed with Phase Two (2017) 
Proceed with Phase Three (2018) 
Multiple process steps are necessary prior to commencing.