Weekly Specials


Runway Numbers

Runways are numbered according the magnetic compass direction they are oriented to.  They consist of two numbers, one at each end of the runway, each being the reciprocal of the other on the magnetic compass (180° opposite from each other).

One number is formed by rounding the compass bearing of one end of the runway up or down to the nearest 10° and dropping the last digit; if this results in a single digit, add a zero to the left of it. The other number is the reciprocal of the first number (see the table of Reciprocal Runway Numbers below). For example, if a runway is aligned north-south, then it is 18/36, not 00/18. The lower number is always listed first.

Runways have two ends.  Each end is considered a different runway, even though it is the same actual runway surface.

If the compass heading of a runway is 122° you would round it down to 120 and drop the last digit, leaving you with 12. Thus it is called Runway 12/30.

If the compass heading of a runway is 37°, you would round it up to 40 and drop the last digit, leaving you with 4. Since this is a single digit, you add a zero to the beginning, giving you 04. Thus it is called Runway 04/22.  Both Ellington and Hobby airports have a 04/22 runway.

Runways are numbered between 01 and 36. The number indicates the runway’s heading. On a compass North is 360°, East is 90° South is 180° and West is 270°. You cannot have a runway zero. The two digit number is essentially 1/10th of the magnetic heading of the runway ±5° i.e. one digit per ten degrees. A runway pointing to the north with a heading from 355° to 004° will be generally given the number 36 (1/10th of 360° ±5°), similarly runway 09 points east (85°~94°), runway 18 is south (175°~184°), and runway 27 points west (265°~274°).

Since a runway can be normally used in two directions (there are always exceptions), it will have a second number which will always differ by 18 (180° or half way across the compass). In India most airports have an east-west runway 09-27



Reciprocal Runway Numbers


North/East end 


 South/West end

01   19
02   20
03   21
04   22
05   23
06   24
07   25
08   26
09   27
10   28
11   29
12   30
13   31
14   32
15   33
16   34
17   35
18   36

For example, in the runway diagram below, this is considered runway 9/27.  If you are looking to the east, you are on runway 9, if you are looking to the west, you are on runway 27.

On an airport diagram, you will see the exact magnetic heading of that runway printed along side the runway:


For more information , visit: http://virtualskies.arc.nasa.gov/communication/3.html

Runway markings

There are runway markings and signs on most large runways. Larger runways have a distance remaining sign (black box with white numbers). This sign uses a single number to indicate the thousands of feet remaining, so 7 will indicate 7,000 ft (2,134 m) remaining. The runway threshold is marked by a line of green lights.



Learn more at https://en.wikipedia.org/wiki/Runway