Airport Runway

The blue skies above hide small specks of grey and shiny silver bellies that seem to move extremely slowly across the sky but are in reality traveling faster than anything on the ground. You squint up into the clouds, trying to find the highest flight, and just when you think you spotted something so very distant, the strain on your eyes causes you to blink and lose the last hope of eyeing that elusive target. At large airports with more than three parallel runways (for example, at Los Angeles and John F. Kennedy International Airport) some runway identifiers are shifted by 10 degrees to avoid the ambiguity that would result with more than three parallel runways. Runways are named by a number between 01 and 36, which is generally one tenth of the magnetic azimuth of the runway's heading: a runway numbered 09 points east (90°), runway 18 is south (180°), runway 27 points west (270°) and runway 36 points to the north (360° rather than 0°). Runway designations change over time because the magnetic poles slowly drift on the Earth's surface and the magnetic bearing will change. As runways are designated with headings rounded to the nearest 10 degrees, this will affect some runways more than others. For example, if the magnetic heading of a runway is 233 degrees, it would be designated Runway 23. If the magnetic heading changed downwards by 5 degrees to 228, the Runway would still be Runway 23. For clarity in radio communications, each digit in the runway name is pronounced individually: runway three six, runway one four, etc.