Wherever you go, navigation aids play a crucial role in ascertaining one’s position and in providing a sense of direction that could have otherwise been marred with confusion. Pilots, specifically, have to be well acquainted with airport signs, marking, and lighting in order to have seamless maneuvers while inbound and outbound airports.
Even though these signs, markings or lighting may be more confusing at the beginning for less experienced pilots, over time, as nature puts it, “practice makes perfect.” Not only will they be interpreting them naturally, but also will be taking off and landing aircraft of different shapes and sizes with ease.
Therefore, we will be looking at the different airport markings, the six types of airport signs, and a snapshot of airport lighting. But first, let’s demystify some useful background information that will make our lives much easier when we get into complex subjects.
It will be important for us to understand the basic layout of airport runways, the location of airport signs, and how runways and taxiways are named before divulging into the finer details of the subject.
Having been to an airport before, I am sure you have come across some signs labeled “23, 17, A, B, or B1.” Well, there are different meanings attached to each of these but generally, numerical and alphabetic designations are linked to runways and taxiways respectively.
For example, from our abstract signs identified earlier, the signs “23 and 17” would be alluding to runways and so will “A, B, or B1” refer to taxiways. However, you’ll notice that the sign “B1” takes a slightly different trajectory from the naming convention just explained.
Imagine large airports that have so many different taxiways that if all named, wouldn’t fit within the A to Z alphabet. Therefore, alphanumeric identifiers such as “A2, R6, and P8” are adopted to make up for the many taxiways.
Equally, double alphabet letters of the same kind such as “CC, FF, KK, and ZZ” are employed as complementary options to the alphanumeric identifiers of taxiways. However, just as you won’t see vehicle number plates with the letters “O and I,” the same letters together with the letter “X” are excluded from the nomenclature of taxiways.
Why? Your guess is as good as mine – to avoid confusion with runway nomenclature that employs numeric and at the same time, prevent the interpretation of the runway or taxiway as closed.
On the other hand, the numbering system of runways employs their magnetic compass heading. However, only the first two digits within a compass reading of 0 to 360 degrees are taken into account in the nomenclature. For example, a runway with a compass heading of 084 will be named runway 8, and so will that of heading 260 be runway 26, and so on.
Whenever a pilot is approaching a runway let’s say runway 9 on the opposite end of the runway, East vs West, the other runway would be named runway 27. As such, from the basic arithmetic principle of angles in a straight line add up to 180 degrees, the two runways will be 18 apart.
Additionally, in the case of parallel runways, which we will define later, the suffixes “L, C, and R,” meaning left, center, and right, are added to the runways’ names whenever they have the same compass heading. For example, runways “9L and 9R” would refer to two parallel runways, and in the case of a third, it would be named runway “9C.”
Now, one may ask, what if such runways are more than three? Well, the standard rule is to have the airport increase or decrease the numerical designation of the runway by one. For instance, as in the case of runways “9L, 9C, and 9R” above, the other parallel runways would be either of the two sets – “10L, 10C, 10R” or “8L, 8C, 8R.”
Airport signs are more often located on the left side of the runway. It, therefore, means that if there is only one type of airport sign it would more likely be on the left of the runway. However, this can change depending on the preferences of the airport operator at the design stage of the airport.
Regardless of where the sign is located, some characteristics of a good airport sign include high visibility to the pilots and ease of interpretation. As such, the pilot, from the cockpit, should easily see an airport sign from a significant distance and be able to tell the nature of directions or information contained in the sign with ease.
An airport runway could have the following layout:
The positioning of these runways is to allow the utilization of prevailing winds by aircraft.
Parallel runways are useful in allowing two aircraft to take off and land on the first and second runways respectively. As such, they come in handy when the wind is consistently blowing from one direction.
These runways are utilized when winds change direction more often throughout the year. They are characterized by land and hold short operations (LAHSO), which helps to increase airport capacity by allowing more users of the airport facilities. Equally, there could be many intersecting points of the runways.
Unlike an intersecting runway, an open-v runway diverges from different directions. Consequently, they do not intersect but instead form a “V” shape. This allows for simultaneous usage of the runways especially when there are little to no strong winds. Otherwise, only one runway can be used at a time.
Runway markings are normally white whereas those of taxiways and holding areas are yellow.
These markings provide alignment guidance to the airplane during landing and takeoff. They also indicate the center of the runway. The lines are 120 and 80 feet in stripes and gaps respectively.
They reveal the beginning of a runway when the threshold has been relocated or displaced. Normally, the width of the bar is 10 feet and extends across the runway’s width.
They depict the beginning of a runway that is available for landing. They can be of two arrangements, either with eight stripes of symmetric dimensions about the centerline or the number of stripes as a function of the runway width.
Normally located at any other point apart from the beginning of the runway. White arrowheads are located across the width of the runway before the threshold bar and white arrows are situated along the centerline in the region separating the beginning of the runway and the displaced threshold.
They help in landing an aircraft by serving as visual aiming points. They are two rectangular markings with a broad white stripe situated on either side of the runway centerline and about 1000 feet from the landing threshold. Depending on the length of the runway, the length of the markings is 100-150 feet or so.
They are composed of 1, 2, or 3 groups of rectangular bars which are symmetrically located in pairs about the centerline. They help in identifying the touchdown area for airplanes.
These markings outline the edges of the runway.
They are continuous yellow stripes that identify the pavement areas surrounding the runway and hence are not meant for aircraft use.
Used for taxing or “land and hold short” operations which are usually used by the air traffic controller. These markings are often placed on runways just before intersecting with another runway.
These are yellow bars that depict displaced runway thresholds from unusable pavement such as blast pads, taxiways, or stopways that precede the threshold.
These are yellow markings aligned with the runway that reveal the pavement areas that are not usable for taxiing, landing, and takeoff.
During taxiing, these markings on the airport tarmac help aircraft to remain centered. The markings take the form of a single continuous yellow line. As a precaution, pilots should observe wing tip clearances of their aircraft because being centered in the taxiway doesn’t necessarily mean good clearance of the wing from obstacles.
They indicate that the pavement is not usable. For instance, the paced shoulders on taxiways or aprons may be used to prevent water erosion and in no way intended for use by the aircraft.
Enhanced taxiway centerline marking is specifically used in larger airports to send a precaution to aircrew that they are approaching a runway holding position marking. They are characterized by a dashed yellow line on each side of the normal taxiway centerline and begin at about 150 feet before the runway holding position.
These signs act as taxiway confirmatory marks for the aircraft. They are situated on the right side of the centerline.
They assist in defining the edge of the taxiway when there is no alignment of the edge of the taxiway edge with the pavement’s edge.
They are useful when supplementing taxiway direction signs at intersections or when it is hardly possible to provide taxiway direction signs.
They are situated at points along low visibility taxi routes to help in taxiing aircraft’s location during low visibility situations. Consists of an outer white or black ring with a pink circle in the middle.
As already mentioned, a runway holding position sign points towards the presence of intersecting runways. As such, the airplane must stop after reaching these points until further clearance is given by the ATC. They consist of four yellow lines, two solid and two dashed, spaced 6 to 12 inches apart, and extending across the width of the taxiway or runway.
These markings can be found in the following areas:
When instructed by the ATC to hold short of the taxiway, the pilot must stop the aircraft such that none of its parts extends beyond the holding position marking or at least provides enough clearance from another aircraft in the intersecting taxiway. Consists of a single yellow dashed line extending across the width of the taxiway.
When instructed by the ATC, the pilot must hold short of ILS critical area until clearance is granted by the ATC. Consists of two yellow solid lines, horizontal, connected by a pair of solid lines, vertical, extending across the taxiway’s width.
These signs supplement those of the holding position. They consist of a red background with a white inscription.
They indicate the route that vehicle operations can be carried out which could be in the same areas that are also used for aircraft operations.
Using navigation aid (NAVAIDS) signals, these marking enables the pilot to check aircraft instruments. It consists of a painted circle with an arrow in the middle, with the arrow aligned in the direction of the checkpoint azimuth.
These runways and taxiways will have the lighting circuit disconnected. As such, there is the destruction of the runway threshold, runway designation, and touchdown markings. Also, yellow crosses are painted on both ends of the runway at intervals of 1000 feet.
A yellow cross may be used to denote these runways or taxiways but they are not permanent markings.
Is denoted by one solid and one dashed yellow line denoting areas not in the control and within the control of ATC respectively. As such, the markings define the movement area under the control of ATC.
Having looked at airport markings, you are probably wondering how different they are from airport signs. Whereas markings, such as runway markings, are painted on a runway’s surface, signs are generally vertically positioned and sometimes painted on runway surfaces.
Signs are almost everywhere around the airport because of the need to inform and remind cabin crew, airport personnel, and even the public about airport operations.
Take a case of how busy the CBD of a notable city like Munich or Dubai is and how the road traffic would have to be managed! Even more, how do new drivers maneuver their way through such cities?
It is at this point that you’ll almost certainly appreciate the important role that road signs and markings play. This analogy is true for airports.
There are six types of airport signs. Therefore, it means that all the airfield signs fall within the six categories namely mandatory instruction, information, direction, destination, location, and runway distance remaining signs.
These signs have a yellow background with a black inscription showing a destination at the airport. The inscription consists of arrows and text, with the arrows pointing toward the destination and the text describing the destination. Such locations can include terminals, civil aviation areas, and cargo loading and offloading points amongst others.
One way of remembering this category of airport signs is by recalling that if you are to describe a destination to someone, you’ll always provide a sense of direction together with the name of the location and hence the purpose of the arrow and text.
Because you’ll normally move either toward or away from a given location, destination signs are of two types namely, inbound and outbound. When in fact outbound destination signs point towards takeoff runways, inbound destination signs point towards main locations at the airport and away from taxiways.
Some of the commonly used inbound signs and abbreviations at the airport include:
However, because of different airport construction and naming requirements, which can vary from one airport to another or across different nations, we recommend that pilots get to familiarize themselves with each airport destination sign because some abbreviations might be interchangeable from one airfield to another. Therefore, it is best if you just understood the naming concept rather than memorize the destination signs described above.
Almost like destination signs, direction signs equally have a yellow background with a black inscription. They help in identifying the designations of intersecting runways. Also, arrows that indicate the direction of the turn normally accompany the designations.
The signs are normally located to the left before an intersection. However, when they are used to indicate an exit on a runway, they will be located on the same side of the runway as the exit.
Therefore, there are two types of direction signs namely runways exit signs and taxiway direction signs. What is unique about runway exit signs is that they are always standalone in that they are not combined with other signs such as location signs.
Consequently, there will be just one directional arrow plus a single taxiway designation for each runway exit sign.
These signs have a red background with a white inscription. They are used to show that one is entering a runway or a critical area. Similarly, they are used to denote that an aircraft is entering a prohibited area at the airport. Undoubtedly, this is typical of the symbolism of the color red denoting aggression and danger, which requires that people should follow the critical instructions contained in them.
There are four main types of mandatory instruction signs, including:
As the name suggests, they tell the pilot not to enter a certain area.
They are used together with pavement markings to advise the pilot that he or she is not supposed to cross until after attaining ATC clearance. As such, they establish a threshold with the pavement markings.
In the absence of a towered airport, the pilot, through good airmanship, must establish that the runway is clear and that there is no aircraft on final approach to that specific runway before crossing it. Therefore, runway holding position signs serve the same purpose as a STOP sign for road traffic, which helps in improving air and road safety respectively.
Food for thought! While driving a car, would you proceed past a road junction under full vehicle throttle? Alternatively, would you disregard traffic lights just because there is no traffic police manning the road?
They pair with the pavement markings to establish a threshold that the pilot isn’t supposed to enter a given runway until after attaining ATC clearance. Technically, they aid in protecting the departure and approach areas of the airport.
ILS stands for instrument landing system. Whenever ILS is used, conflict may arise with the use of the usual holding position location. The writing “ILS” is thus used with the holding position sign and placed adjacent to the taxiway’s holding position marking.
These signs have a yellow background with black writing. They are used to furnish the pilot with information about items that are not visible from the control tower, radio frequencies that are in force, and noise abatement procedures. Even road transport has similar signs and those are known as informatory signs.
These can include bump ahead, minimum, and maximum speed limit signs. As such, even in the absence of traffic police, motorists can tell what information is applicable using road informatory signs.
Depending on the preferences of the airport operator, these signs usually have varying sizes, are situated in different locations, and serve different purposes from one airport to the next.
Actually, in comparison with the other five categories of airport signs, this is the least regulated by the FAA. However, the colors of the information signs are standardized.
Location signs have a black background with yellow lettering, and a yellow border, and don’t have any arrows. They are used to show where the aircraft is located on either the runway or taxiway. There are four types of location signs namely:
They tell the exact taxiway in which the aircraft is currently located.
As the name suggests, they tell the exact runway in which the aircraft is currently located or the runway your taxiway is intersecting with.
The role of a runway boundary sign is to simply demarcate the exit of the runway.
They indicate and designate the beginning of the ILS critical area. This helps the pilot to stay clear of the ILS critical area.
Runway distance remaining signs have a black background with a white numerical inscription. The number on the sign indicates the remaining distance, normally in thousands of feet, of the landing runway remaining.
Therefore, during approach and landing, the numbers on the signs will decrease proportionately as the aircraft nears the end of the runway or comes to a stop.
Equally, shorter runways may have fractions such as ½ instead of whole numbers, 1 and 2, etc.
As you’ve noticed, some airport signs may contain at least two pieces of information, which link to at least two categories of airport signs in one sign. These are known as combination signs. Let’s have a look at some of the common ones.
Lighting is important in aiding visibility. With most commercial aircraft capable of flying under instrument flight rules, IFR, they can fly in extreme darkness especially at night, even over long distances.
Equally, even for helicopters that normally fly under visual flight rules, VFR, harsh weather conditions such as dust storms, heavy rain, and fog may hinder the pilot’s visibility and hence compromise safe landings.
These reasons make it prudent to have adequate airport lighting, particularly on the runways and taxiways to enable safe and accurate landing and taxiing of aircraft.
Even though the airport is furnished with many different kinds of lighting systems including approach lighting systems, visual glideslope indicators, and airport beacons, we will focus on just two types, runway, and taxiway lighting.
They identify the end of the runway and consist of two synchronized flashing lights.
They are extensively white lights that define the edge of the runway. They can sometimes be yellow lights on instrument runways. Based on the intensity of the lights they are emitting, they can be high-intensity, medium-intensity, and low-intensity runway lights, abbreviated as HIRL, MIRL, and LIRL.
They define both ends of the runway such that they emit red and green toward and away from the runway to show the end of the runway for a departing aircraft and the threshold for landing aircraft respectively.
They are steadily burning white lights that are normally installed on precision approach runways to show a touchdown zone under low visibility.
They are extensively white lights at the beginning of the runway, with alternating red lights in between, and finally red lights toward the end of the runway. They are spaced 5o feet apart and aid in landing.
They are alternating green and yellow lights from the runway centerline to the ILS critical area or the holding position. They help pilots in exiting the runway.
They are alternating green and yellow lights that help pilots when entering the runway.
During the land and hold short operations, LAHSO, the row of pulsing white lights come on.
They depict the edge of taxiways and are normally used during low visibility. They burn steadily and emit blue light.
They aid in facilitating ground traffic and are located along the centerline of the taxiway. They burn steadily and emit green light.
They are located on taxiways to provide access to an active runway. They are alternatively flashing yellow lights and help to identify the location of a runway holding position marking.
Used to increase the visibility of the holding position. They are three and emit yellow lights and are installed on pavements.
They are located at the runway holding position and one must get an ATC clearance before crossing. They are unidirectional red lights existing in a row.
They blink alternatively and are also referred to as “wig-wag” lights.
As evidenced by the discussion, so many unsung heroes work behind the scenes to ensure that there is adequate airport infrastructure in place to facilitate the safer maneuverability of aircraft by pilots.
Such an infrastructure ranges from airport signs to markings and lighting amongst others. Even though the details of each could be overwhelming to a beginner pilot or cabin crew in general, with experience, recalling most, if not all, of this information, can be done with ease.
Further, although our analysis has been extensive, it hasn’t been exhaustive. We always recommend that for airport-specific information you consult the relevant airport manuals amongst other navigation aids for a more elaborate and accurate assessment of this subject.
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