Missoulas runways are designated 11-29, and 7-25. Why?
Runways are generally numbered according to the magnetic direction in which they point rounded to the nearest ten degrees and then divided by ten. Each digit is pronounced separately for clarity in radio communications. For example, Runway “two-nine” would be aligned in roughly a 290 degree heading, while runway “one-one” is about 110 degrees. Missoula’s other two runways are 7 and 25, which are aligned roughly 70 and 250 degrees respectively. So what would happen if Missoula International Airport were to build a new runway parallel to the existing main runway 11-29? The two parallel runways would be differentiated by a letter “L” for Left, and “R” for Right following the heading numbers. For example, the existing runway 11-29 would become 11L-29R, while the new runway would be designated 11R-29L.
