How are the runways numbered?
SAT has six runways arranged as a pair of parallels runways and a cross runway. All these runways are designed to face the most prevailing wind directions, since aircraft must both takeoff and land into the wind. The runway ends are named according to their magnetic compass heading with the last zero dropped off. For example the SAT parallel runways are 12L/30R and 12R/30L have magnetic headings of 120 degrees and 300 degrees respectively and runway 3/21 has magnetic headings of 30 and 210 degrees respectively.
