RUNWAY NUMBERS AND THEIR MEANINGS

I just wanted to simply start explaining the meaning of these big numbers painted at the end of runways.

These are symbolizing the numbers range between 0°-360°. As you can see, there is not any

number painted on the runway like 183, 191 or 280 or 152 etc. These are the

decadegrees numbers ranging 0-36 and symbolizing the 0°-360°. So if runway number is 05

then the runway position is 50° or approximately 50° or runway 18 then the runway is 180° or

approximately 180° and also runway 36 points the north (360° rather than 0°). If the runway points

358° then the runway is 36 or the runway points to 253 ° then the runway is 25 etc. Also one runway

has two number from opposite sides differ by 18. It means 180 ° from other side such as runway

5R/23L or 5L/23R or runway 18/36 etc. Most airport drop the leading zero number from runway. For

example instead of runway zero five (05), it is runway five (5). In the first picture it is runway 18,

the second picture runway 19R, the third picture is 28L. The appendings 'R' and 'L' mean 'Right' and

'Left'. Because there are some airports consists of more than one runways paralel to each other.

Sometimes there are more than one or two runways parallel to each other. In this case, runways are

named 19R and 19L or 17R,17C,17L etc... The 'C' appending mean 'Center'. Because there are

sometimes more than two or three runways parallel to each other. At Dallas/Forth Worth

International Airport there are five parallel runways named 17L, 17C, 17R, 18L and 18R.

These identifiers are shifted by 10 degree to avoid ambiguity and all are oriented at a heading of

175.4 degree.


These numbers are oriented according to Magnetic North Pole differs from North Pole. This is

the North Pole also called Georgraphic North Pole.

 Magnetic Pole is not in the same location true north and moves 10 to 40 km per year.

The picture above shows us the Magnetic North Pole changes according to the Polar Shift at the core of Earth.

It is a simple picture that shows us the compass and how it works according to Magnetic North.

All these runway numbers are designated in regard to Magnetic North Pole which is shifting every year even now. With Polar Shift, runway number might change. For example if runway 23 degree is 229 and with the polar shift, if it becomes 227 by 2 degree downward then runway number remains same but if it jumps to 232 degree by 5 degree upwards then runway number will change and it will be runway 23. This is not common and not welcoming situation for airports. With the change of runway numbers, documentations for aviation will be changed and the runways have to be repainted.

For instance, Cork Airport Runways change over 50 years as a result of Earth's magnetic poles.

http://www.irishexaminer.com/ireland/designation-numbers-of-cork-airport-runway-to-change-for-first-time-50-years-377269.html

 It does not mean that after Magnetic Pole change, all runways will be affected by this situation, It might vary from countries to countries, cities to cities.