Runways numbers and letters.

As most of  us visit the airport to travel(by airplane). 

There if you notice the runways are marked with white strips, numbers and letters.

These numbers,letters have unique meaning if you deep examine.That is at the time of take- off and landing the pilot has to see the magnetic needle(azimuth) direction,based on the direction of compass and with the guidance of ATC(air traffic controller) the pilot does the work.
so in this post i will explain the meaning of that numbers and letters.


So how are runways numbered? Sequentially, based on the number of runways at the airport? No.
 All runways are numbered based on the magnetic azimuth (compass bearing) in which a runway is oriented. There are 360 degrees on a compass. Runway numbers are determined by rounding the compass bearing of one runway end to the nearest 10 degrees and deleting

→↔↓→→→↓

the last digit, meaning runways are numbered from 1 to 36—as per the diagram above.

You might be thinking that the numbers on this diagram are backwards. On a handheld compass, south is 180 degrees (so 18 in runway terms) and west is 270 (27). But the “W” is numbered 9 because the runway number is connected to the direction the plane is traveling. So if you’re on runway 9, then you’re heading east (90 degrees on a compass). Runway 36 means you’re moving north, and so on.

The opposite end of the runway always differs by 180 degrees, so it’s numbered 18 higher or lower.  For example, Runway 9-27 is oriented east-west.

Many large airports have parallel runways, which requires further designation of each runway. One is Runway 4L-22R and the other 4R-22L. The ”L” and ”R” designate the relative position (left or right) of each runway respectively when approaching/facing its direction. A small number of airports have three parallel runways—the runway in the middle gets a “C” for center.

During airport operations, runway number designations are pronounced individually.  For example, Runway 4L-22R would be pronounced by air traffic control as “Flight 123, you are cleared to land on Runway Four Left” or alternatively “…Two Two Right,” if cleared to land the opposite direction. This kind of annoucement ensures clear communication and enhances safety. 

So the next time you travel by air plane and the pilot announces that you’ll be taking off on runway 27, you'll know that you’re traveling due west.

HAVE A NICE JOURNEY.
ENJOY YOUR FLIGHT.

Edit,suggestion,correction and appreciation are  most welcome.

Yours Chandra shekar.