ICAO shares Standards and Recommended Practices(SARPs) for airport signs, runway and taxiway markings, mandatory instruction signs, information signs, mandatory instruction markings, runway holding position markings, etc. via Annex 14, Aerodromes.
MANDATORY INSTRUCTION SIGNS
A mandatory instruction sign indicates a location beyond which an airplane may not proceed unless authorized by air traffic control. At uncontrolled airports, take appropriate precautions before proceeding. Mandatory instructions signs may include runway designation signs, category I, II, or III holding position signs, and NO ENTRY signs. A NO ENTRY Sign is posted when entering into an area has been prohibited.
- Mandatory instruction signs have white text/inscription on a red background
- Mandatory instruction signs for a category I, II, or III or joint II / III holding position will be the runway designator followed by CATI, CATII, or CATIII as appropriate
- On a runway holding position sign, the inscription will be the taxiway designation and the corresponding runway number
Although they give specific information the color usage in information signs is more generic in nature. Information here includes location, destination, runway exit, direction, runway vacated signs, etc. These signs are located on at least one side of the taxiway.
Note: A runway vacated sign is provided where the exit taxiway has no centerline lights and there is a need to indicate leaving the runway, the ILS/MLS critical/sensitive area.
Information sign has black text/inscription on a yellow background
MANDATORY INSTRUCTION MARKINGS
Where it is impractical to install a mandatory instruction sign, a mandatory instruction marking is placed on the surface of the pavement. When operationally required, such for example on taxiways exceeding 60 meters in width, a mandatory sign may be supplemented by mandatory instruction marking.
- Mandatory instruction marking is located on the left-hand side of the taxiway centerline marking
- Mandatory instruction marking consists of text/inscription in white on red background
RUNWAY-HOLDING POSITION MARKINGS
As the nomenclature suggests runway-holding position markings are located at runway holding positions. Please refer images below for two types of marking patterns:
The intersection of taxiway and non-precision, non-instrument or take-off runway or where only a single runway-holding position is provided at the intersection of a taxiway and a precision approach CAT 1, 2, or 3 runway. Only pattern A markings are present in such case.
The intersection of taxiway and precision approach runway where there is more than one holding position considering ILS critical/sensitive area. Both pattern A and B markings are present in such case.
STOP BAR LIGHTS
When it is intended that the runways will be used in RVR conditions less than 550m, a stop bar is provided at each runway holding position. A stop bar will be provided at an intermediate holding position to supplement markings with lights or where normal stop bar lights might be obscured. Stop bar lights are located across the taxiway at a distance of 0.3 m before the holding point line. Aircraft is expected to stop as long as lights are ON. Stop bar consists of a series of lights spaced at equal intervals embedded in the pavement and are unidirectional showing steady red.
RUNWAY GUARD LIGHTS
Runway guard lights are a system of two unidirectional yellow flashing lights intended to warn pilots or vehicle drivers that they are about to enter an active runway. The act has the first line of defense against runway incursion. They help in raising situation awareness but be mindful they are not mandatorily available.
They’re located at each end of a taxiway at a holding point where the taxiway meets a runway. Both aircraft and vehicles must wait there until given clearance by air traffic control (ATC) to proceed. They must be in use when RVR is less than 1,200 meters. They are usually elevated, but this is no longer a requirement.
Threshold markings are provided at the threshold of a paved instrument and non-instrument runway. Runway threshold markings are stripes of uniform width and length disposed symmetrically about a runway’s centerline.
When the runway designation is placed within a threshold marking, there will be at least three stripes on either side of the runway center line. Stripes in threshold markings are at least 30m long.
|Runway Width||Number of Stripes|
RUNWAY DESIGNATION MARKINGS
Runway designation markings consists of two digit number located at the threshold. It is the closest whole number to one tenth of the north magnetic pole when viewed from the direction in which an airplane approaches the airport.
Following are some examples of runway designator-
|Magnetic Course||Runway Designator|
For parallel runway nomenclature includes letter L (left), R (right) and C (center).
- two parallel runways: “L” “R”;
- three parallel runways: “L” “C” “R”;
- four parallel runways: “L” “R” “L” “R”;
- five parallel runways: “L” “C” “R” “L” “R” or “L” “R” “L” “C” “R”
RUNWAY CENTERLINE MARKINGS
Runway centerline marking provides alignment guidance during takeoff and landing. Since their primary purpose is to guide the aircraft at high speed, the centerline consists of uniformly spaced stripes and gaps. This gap ensures a better visual perspective at high speed. These stripes are normally 30m long with gaps 20m long.
HIGH-SPEED TAXIWAY TURN-OFF INDICATOR LIGHTS (HSTIL)
RETIL – Rapid Exit Taxiway Indicator Lights, is the term used by ICAO. RETIL should be provided on a runway with heavy traffic density and/or RVR conditions less than 350m. They are fixed unidirectional yellow lights in configurations three, two, and one, spaced 100m apart on the same side of runway centerline as associated rapid exit taxiway.
RUNWAY TOUCHDOWN ZONE MARKINGS
The touchdown zone markings indicate where the touchdown zone begins and ends. They’re coded to provide distance information at 150 m intervals.
Runway Pattern 1: These markings consist of pair of rectangular bars symmetrically arranged about the runway centerline.
Runway Pattern 2: These markings consist of groups of one, two and three rectangular bars symmetrically arranged about runway centerline.
Number of pairs of markings defining the touchdown zone depends on landing distance available (LDA).
|LDA or Distance between thresholds||Pair(s) of Markings|
|Less than 900m||1|
|Less than 1200m but not less than 900m||2|
|Less than 1500m but not less than 1200m||3|
|Less than 2400m but not less than 1500m||4|
|2400m or more||6|
RUNWAY AIMING POINT MARKINGS
Aiming point marking consists of two large solid stripes with dimensions as per undermentioned table. Aiming point markings are provided at each approach end of paved instrument or non-instrument runway.
Location and dimensions of aiming point marking:
|Location and Dimension||Landing Distance Available|
|Less than 800m||800m up to but not including 1200m||1200m up to but not including 2400m||2400m and above|
|Distance from threshold to beginning of marking||150m||250m||300m||400m|
|Length of stripe||30-45m||30-45m||45-60m||45-60m|
|Width of stripe||4m||6m||6-10m||6-10m|
|Lateral spacing between inner sides of stripes||6m||9m||18-22.5m||18-22.5m|
RUNWAY SIDE STRIPE MARKING
Runway side stripe markings consist of two stripes, one placed on each edge of the runway. These markings are no more than 30m from the runway centerline regardless of runway width.
DISPLACED THRESHOLD MARKINGS
Displaced threshold markings can be for temporarily displaced threshold as well as permanent displaced threshold.
Usage of area behind temporarily displaced threshold
In fig. 1 and 2, area behind displaced threshold can be used for taxi, take-off, and completion of landing roll. It can not you used for landing.
In fig. 3, area behind displaced threshold can not be used for any purpose
In fig. 4, area behind displaced threshold can be used as stop way only
CLOSED RUNWAYS, TAXIWAYS OR PARTS THEREOF
Runway Closure Marking (full or in part)
Close marking shaped like a cross in “white” is displayed at each end of the runway or applicable portion. This indicated that the area is declared permanently closed to use by all aircraft. The maximum difference between markings must not be more than 300m. If required, more crosses can be used.
Taxiway Closure Marking (full or in part)
Close marking shaped like a cross in “yellow” is displayed at each end of the taxiway or applicable portion. This indicated that the area is declared permanently closed to use by all aircraft. The maximum difference between markings must not be more than 300m. If required, more crosses can be used.
Pre-threshold Area Marking (Chevron Marking)
When the paved surface before the threshold exceeds 60 meters in length and is not fit for use by aircraft, its entire length will be marked by a chevron marking pointing in the direction of the runway threshold.
Stop way vs Pre-threshold Area
Pre-threshold areas may or may not be designated as stop ways. The difference is not in how it looks, but how strong it is, if it is maintained, graded, or whatever else. The reason the markings on the runway are the same is that neither a stop way nor a pre-threshold area is suitable for landing; therefore, they direct the approaching aircraft to an appropriate spot. Many times runway-grade certified surface is also marked off as a pre-threshold area because of takeoff and approach slope restrictions.
To know whether a stopway is available, regardless of its appearance, you must consult the runway data, which declares distances.