Curious about the meaning of certain markings on the runway? These visual indicators are vital for pilots, helping them perform safe, efficient takeoffs and landings. Let’s take a look at the key points of airfield markings from CAP 637 – Visual Aids Handbook.
Introduction
Surface markings at aerodromes are implemented to help pilots identify specific locations and provide guidance for ground movement during daylight hours, they are often complimented by signage and are normally produced by the application of skid resistant paints or thermo-plastic materials directly onto the pavement.
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Types of Markings
Runway Markings are WHITE.
Taxiway Markings are YELLOW.
More information can be found on our Guide to Taxiway Markings.

Detailed Explanations
Letters correspond to Figure 2.1 above from CAP 637.

a. Runway Designation Markings.
All paved runways are identified by a Runway Designation Marking which consists of a two digit number indicating the magnetic heading of the runway to the nearest 10 degrees.
For example, a runway aligned at 183 degrees would be rounded to 180, making it Runway 18. When communicating over the radio, it’s referred to as Runway One-Eight rather than Runway Eighteen. In the U.S., the leading zero for runways numbered 1 through 9 is omitted, so we say Runway Two instead of Runway Zero-Two, which is common in other countries.
For parallel runways, an additional designator is used, with “L” for left, “C” for centre, and “R” for right.
If you come across a Runway marked with an “X,” it indicates the runway is closed, not the Roman numeral for 10.
Since runway numbers are based on magnetic headings, and the Earth’s magnetic field gradually shifts, runway numbers can change over time.

b. Threshold, Edge & Centreline.
All paved runways have Centreline and Threshold Markings. The Threshold Markings differ according to the classification of the runway.
B) Non Precision Approach Runways
Runway Edge Marking is normally provided on all ILS equipped runways and those other runways where there is insufficient contrast between the runway and its shoulders or where the declared runway width is less than the paved width. Non-precision approach visual runways markings, usually in the form of white stripes across the runway, highlight the beginning of the runway available for landing.
C) Precision Approach Runways
Precision approach runways are equipped with sophisticated instrument landing systems (ILS) or other precision-based guidance systems. These runways offer precise vertical and lateral guidance to pilots during approaches and landings, even in adverse weather conditions with reduced visibility.
c. Displaced Threshold Markings.
While Threshold Markings are normally located at the beginning of the paved runway surface, they may be displaced along the runway where, for example, there are obstructions on the approach or where the first portion of the pavement is unfit for the movement of aircraft.
Where displacement is of a temporary nature, e.g. to accommodate runway maintenance, the normal threshold markings will be obscured and the appropriate Displaced Threshold Marking and threshold marker boards, illustrated at Figure 2.1 (e), put in place in order to mark the new threshold.
Whenever a threshold is displaced, the pre-threshold area will be marked according to its usability at Figure 2.1 (d) and (e).
d. TDZ and Aiming Point Markings
All ILS equipped runways and those other runways where the touchdown zone is insufficiently conspicuous are provided with TDZ and Aiming Point Markings as shown at Figure 2.1 (c).
These markings are intended to give added visual cues to the runway surface, particularly in conditions of poor visibility; they also indicate the optimum touchdown zone on the runway.
The apparent distance between the Aiming Point Marking and the Runway Threshold Marking, as seen from the approach, is intended to aid pilots in judging their angle of approach.
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Helipad Markings

The various heliport markers and markings have different functions. Here are some of them:
“H” Marking
This marking is essential because it indicates that the area is a heliport. It also assists the pilot in the preferred approach of departure and landing.
TLOF and FATO Perimeter Marking
These markings define the parameters or the surface area for the pilot to prepare for TLOF and FATO.
Maximum Allowable Mass Marking
This marking indicates the maximum helicopter weight that can land on the heliport. This marking is especially useful for heliports on top of a building, ship, or helideck.
Frequently Asked Questions
Runway Markings
If you would like to know more, we suggest taking a look at CAP 637 – Visual Aids Handbook

Runway markings serve to guide pilots during takeoff and landing, helping them maintain proper alignment, speed, and distance from other aircraft and runway features. They also indicate areas where aircraft should not taxi or park.
What are the three classifications of runways ?
The three classifications of runways are Visual Runway (VR), Non-Precision Approach (NPA), and Precision Approaches (PA). Visual runways have no instrument approach procedures and rely on the pilot’s visual judgement. NPA runways have basic approaches with a few navigational aids, such as localizers and VORs. PA runways have more complex approaches with multiple navigational aids, such as ILS or GPS-based systems.
Who many feet wide are international Airfield Runways?
150 feet wide. And 6,000 – 15,000 feet long.
Why are lines colored white and yellow?
White markings are used for runway centerlines, runway edges, and holding positions. Yellow markings indicate caution areas, such as areas that require increased attention by pilots or where aircraft should not taxi or park.
Who is responsible for Airport markings?
Airport authorities are responsible for maintaining runway markings, including regular inspections, cleaning, and repainting.
How often are markings repainted?
The frequency of repainting depends on several factors, including the volume of traffic, weather conditions, and the type of paint used. Typically, runway markings are repainted every one to two years.
What happens if markings are not maintained?
Failure to maintain runway markings can lead to safety hazards, including runway incursions, incorrect takeoff or landing procedures. No to mention collisions with other aircraft or ground vehicles.
What are some common challenges in maintaining markings?
Weather conditions, heavy use, and budget constraints are some common challenges faced by airport authorities in maintaining runway markings.