The Phoenix Sky Harbor airport has over two parallel runways .
Runway Zero Three Left ( 03L ) becomes Runway Two One Right ( 21R ) when used in the opposite direction ( derived from adding 18 to the original number for the 180 degrees when approaching from the opposite direction ) .At large airports with more than three parallel runways ( for example , at Los Angeles , Detroit Metropolitan Wayne County , Hartsfield-Jackson Atlanta , Denver , Dallas-Fort Worth , John F. Kennedy , Orlando , and Phoenix Sky Harbor ) some runway identifiers are shifted by 10 degrees to avoid the ambiguity that would result with more than three parallel runways .
Runway