EXH1255050661

U.S. Army Corps of Engineers _,_ _ Regulatory Branch, Seattle District Office 0 Box 3755 _: C'_"_P.O. Seattle, WA 98124-3766 Dear Ms. Walker: This is a followup to our letter to you of May 31, 2001, in which we indicated we would provide you additional information on issues related to new technologies; the mechanically stabilized earth (MSE) wall; and Section ! 06 activities, as noted in your April 30, 2001, Memorandum for the Record. We offer the following clarifying informatiorL a. New Technologies The Port of Seattle (Port) proposes the development of the third runway to address the airport's existing poor weather arrival constraints. The existing parallel runways at Seattle-Tacoma International Airport (STIA) have a centerline-to-centerline separation of 800 feet. Due to separation standards imposed by Air Traffic regulations, only during visual flight rules 1 (VFR1) conditions (good weather) are two arrival streams possible. In "just below visibility minimums" (VFR2) and under instrument flight rules weather conditions, the airport operates in a single arrival stream. Even with the introduction of current and future technology, the existing runway separations will prevent poor-weather- dual-arrival streams. This is because the existing runway separation criterion requires 4,300 feet to operate dual independent precision instrument approaches, and separations are allowed down to 3,400 feet only with predmion runway monitors (PRM). The Federal Aviation Administration (FAA) has considered alternative technologies to address this poor weather arrival constraint, as documented in the 1996 Final Environmental Impact Statement O/IS) and the 1997 Final Supplemental EIS. As we discussed…

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PSCAA Advisory Council Meeting Agenda
Add to CalendarMWednesday Mar 11, 9:00am - 11:35am
1904 3rd Avenue, Suite 105, Seattle, WA 98101
Call to order – Roll Call – Quorum Established – Land Acknowledgement We would like to acknowledge that our Agency operates in four present-day counties, which are the traditional lands of the Coast Salish people, past and present. This acknowledgement does not take the place of authentic relationships with indigenous communities in our jurisdiction and [...]