Bogan

Implementation of an LDA/DME Approach to Runway 16R in Lieu of a Third Runway at Sea-Tac I. INTRODUCTION The April 1995 Seattle-Tacoma International Airport Master Plan Update Draft Environmental Impact Statement, (DEIS, Chapter 11 ), identifies seven alternatives to "Improve the Poor Weather Airfield Capability In A Manner That Accommodates Aircraft Activity With An Acceptable Level of Aircraft Delay." The alternatives are: a. Use of other modes of Transportation b. Use of other Airports or Construction of a New Airport c. Activity Demand Management d. Runway Development at Sea-Tac e. Use of Technology f. Blended Alternative (Combination of other modes, use of existing airports, and activity demand management). g. Do-Nothing/No-Build The DEIS concludes that the preferable alternative to improve "poor weather" airfield capability is to construct an 8500 foot runway 2500 feet West of Runway 16L/34R. The DEIS infers that an LDA Approach to Sea-Tac is not viable due to the frequency of "poor weather". The Port attributes this conclusion based on the poor weather conditions they claim exist 44% of the year. LDA has and will be referred to many times in this report therefore; following is a definition of the term LDA. The Localizer Directional Aid (LDA) is an electronic beam used to guide aircraft to a specific point in space. It works similar to the localizer beam of an Instrument Landing System (ILS). Unlike an ILS the LDA is not aligned with a runway. The beam is used as guidance through the clouds. After descending clear of…
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