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Here is a portion of Green Airway No. 1, in the state of Washington, in
NW US. Radio Range stations in Ephrata and Spokane defined this portion. See
also the main Radio Range Network Illustration.
East-west airways were Green or Red with a number, while north-south airways
were Amber or Blue with a number. At crossing or merging points, Green
had top priority, followed by Amber, Red, and Blue. GARBo was the memory aid
after the famous film star of the times, Greta Garbo. The chart also shows
the A and N sides for each of the four courses.