Page 138 - Planning and Design of Airports

Air Traf fic Management 107

FIGURE 3-6 MOAs and restricted areas south of Kay Larkin Airport, Palatka,
Florida.

Colored Airways
The earliest airways, created in the 1920s were initially given a color
designation on aeronautical charts and described by their color. The
trunk lines east and west were green, trunk lines north and south
were amber, secondary lines east and west were red, and secondaries
north and south were blue. Each of these colored airways was then
given a number, such as green 3, red 4, etc. The numbering for the
airways began at the Canadian border and the Pacific Coast, then
progressed to the south and east. These airways were then assigned
an altitude level, which for green and red was at odd-thousand feet
eastbound and at even-thousand feet westbound. On the amber and
blue airways northbound, odd-thousand-foot levels were assigned,
and southbound even-thousand-foot levels were assigned. These air-
ways were delineated on the ground by low-frequency medium-
frequency (LF/MF) four course radio ranges. The colored airways
were phased out as aircraft became equipped to use the victor airways
in the late 1940s.