Airports have their very own language when it comes to runway markings. And although millions of people fly all over the world every day, with Heathrow transporting 206,800 people on average every day last year, it is very likely that most people completely overlook the markings that are critical in ensuring their safety.
Effective Line Marking for Every Airport Application
There are so many different forms and reasons for different markings within an airport setting, from designated zones for aircraft, taxiways and regulations even for walkways. You can view some of these in Meon’s Case Study for Dublin Airport. Airports around the world follow the same guiding principles when it comes to their runway markings, with the aim that by using the same symbols and specific line patterns pilots will be able to safely take off and land the plane at any airport around the world.
1. The Blast Pad
At the very beginning of most runways, you will find a ‘blast pad’. This is a patch of what looks like the runway, although it is normally not strong enough to hold the weight of a plane, meaning landing on it would cause a ‘catastrophic error’, and cause a lot of damage to both the surface and the plane. The blast pad is usually painted with yellow chevrons and is designed to prevent the ‘blast’ of departing jets from doing any damage to the surface found just before the runway.
2. The Threshold
A short while after the blast pad is where you will find the threshold. As the name indicates, this marks the start of the ‘real’ runway. The threshold is marked by a number of long and thin white runway markings, which the Pilot uses to indicate the width of the runway with.
|Runway Width||Number of Stripes|
3. Numbers and Letters
If you look at the image below, you will see the letter ‘L’ followed by the number ’26’. Unlike the numbers, the letter you find on the runway (if there is one) is there for a very simple reason; If there are 2 or 3 runways parallel to each other, the letters simply define whether it is the right, left, or centre runway (‘R’,’C’,’L’).
4. What do the numbers on the airport mean?
The number is slightly more mathematical to work out. It is determined by the ‘nearest one-tenth the magnetic azimuth of the centreline of the runway’. Or in a simpler form, the compass bearings of said runway. For example, a runway that is 214° from the magnetic north would first be rounded to the nearest ten: 210°. Then the last digit (the zero) is dropped, leaving us with 21. Now if the runway is being used for both directions, the number facing the opposite way would be 21-18 (210°-180°) = 3. As the Pilot will be looking out for these markings when approaching the airport from the sky to land, they need to be specifically designed so that it is almost impossible to confuse one with the other.
They also need to be the right width and height to be visible. Because of this, runway markings actually has its very own font. Each character must be perfectly marked out in accordance with the designed font, and be exactly 60 feet high, except 6 and 9—which can be 3 feet higher because of the tails. Everything down to the slant at the top of the number 1 has been engineered to give Pilots the clearest view of the runway’s identity.
Further on from the numbers and letters marked out, are the runway markings that the plane actually lands on. These are simply six short white lines parallel to each other. A little bit further up from these, you will find two large white rectangles. This is actually what the pilot aims for when landing, which is why these need to be very visible. Runway markings achieve high visibility through the use of high solids paints, which is referred to here in our knowledge article.