# File lib/wx/groups.rb, line 193
      def initialize(raw)
        raise ArgumentError unless raw =~ /^R(\d+[LCR]?)\/([PM]?)(\d+)(V([P]?)(\d+))?FT$/
        @runway = $1
        @range = ($3+' feet').unit
        @range.minus = true if $2 == 'M'
        @range.plus = true if $2 == 'P'
        if $4
          r1 = @range
          r2 = "#{$6} feet".unit
          r2.plus = true if $5 == 'P'
          @range = [r1,r2]
        end
      end