The direction of runways states 07R/25L or 07L/25R. What do these numbers mean?

Question

The direction of runways states 07R/25L or 07L/25R. What do these numbers mean?

Answer 1

And, let us consider that a runway has the number (painted on the ground) "17". So, the magnetic compass shows 170°, right?

Not so right!

There'a a slight tolerance; if it shows 166 degress till 175 degrees, it is the runway 17; if it shows 165° it is the runway 16; or, 176 degrees, it is the runway 18!

Easy, isn't it?

Answer 2

Runways are identified by a two-digit number that corresponds to its magnetic heading. Think of a circle, like a clock for instance (not a digital clock, obviously!)... divide that circle into 360 pieces, which interestingly enough is the number of degrees IN a circle. The direction that your runways are pointing within that circle, dictates which two-digit number it will be assigned. Another interesting fact is: whatever number is determined to the top of the runway, the bottom of the runway will *always* be 180 degrees less. For example, if your runway at the north or top points to 320 degrees, the bottom of the runway would then be... (320 -180= 140!) 140. Now that you know which way your runway runs, you have to convert the direction into a two-digit number. Drop the zeros in both sums. 320 becomes... 32 and 140 becomes... 14. When there is a letter identifier associated with a runway, there is either 2 or 3 runways that could be used. These are indicated by (L) - left, (C) - center, or (R) - right. Which runway you will be taking off from or landing on depends on the time of day and winds/weather, or if the runway is even operational. You should check with the airfield you'll be operating into/out of for more information.

Answer 3

Magnetic direction rounded and divided by 10.  

Usually, but not always, within 5º.

Left and right.

Answer 4

The numbers are the direction of the runway.  When flying the directions on a compass are represented by the numbers that they represent on a circle.  Each runway has a 2 digit number representing the first two numbers of the degree the runway faces.  Think of a circle and compare it to a compass.  East would be 090 degrees, South 180 degrees, West 270 degrees, and north 360 degrees.  In the example you gave the runway 7R is the right runway and it is facing East North East or 70 degrees.  Runway 25L is the Left runway and is facing West South West or 250 degrees.  Runway 7R/25L is the same strip of pavement but depending on which direction you are flying determines which runway it is.  Runway 7L/25R is the runway on the Left side if flying at 70 degrees or the Right runway when flying 250 degrees.  I hope this helps!

Answer 5

The runway number corresponds with the direction off of magnetic north within a tolerance of 5 degrees to either side. The L/R after the runway number designates the side (left or right side) that the runway is on if there is more than one runway facing the same direction, as in Seattle's airport. Runway numbers can change overtime because the location of magnetic north (The North Pole) can change over time.

Answer 6

Sorry Alice, we pilots really like to make it all sound so complicated, don't we. It's because we want the world to think we're special. We're not, of course, anybody could learn to do what we do but we want the world to think we are.