3. Airport Marking Aids and Signs
Airport pavement markings and signs provide information
that is useful to a pilot during takeoff, landing, and taxiing.
Uniformity in airport markings and signs from one
airport to another enhances safety and improves efficiency. Pilots are
encouraged to work with the operators of the airports they use to
achieve the marking and sign standards described in this section.
Pilots who encounter ineffective, incorrect, or
confusing markings or signs on an airport should make the operator of
the airport aware of the problem. These situations may also be
reported under the Aviation Safety Reporting Program as described in
paragraph 7-6-1, Aviation Safety Reporting Program. Pilots may also
report these situations to the FAA regional airports division.
The markings and signs described in this section of the
AIM reflect the current FAA recommended standards.
AC 150/5340-1, Standards for Airport Markings.
AC 150/5340-18, Standards for Airport Sign Systems.
2-3-2. Airport Pavement Markings
For the purpose of this presentation the
Airport Pavement Markings have been grouped into four areas:
Colors. Markings for runways are white.
Markings defining the landing area on a heliport are also white except
for hospital heliports which use a red "H" on a white cross. Markings
for taxiways, areas not intended for use by aircraft (closed and
hazardous areas), and holding positions (even if they are on a runway)
2-3-3. Runway Markings
There are three types of markings for
runways: visual, nonprecision instrument, and precision instrument.
TBL 2-3-1 identifies the marking elements for each type of runway and
TBL 2-3-2 identifies runway threshold markings.
Runway Marking Elements
runways used, or intended to be used, by international commercial
2 On runways 4,000 feet (1200 m) or longer used by jet
Instrument Runway Markings
Designators. Runway numbers and letters are
determined from the approach direction. The runway number is the whole
number nearest one-tenth the magnetic azimuth of the centerline of the
runway, measured clockwise from the magnetic north. The letters,
differentiate between left (L), right (R), or center (C), parallel
runways, as applicable:
For two parallel runways "L" "R."
For three parallel runways "L" "C" "R."
Centerline Marking. The runway centerline
identifies the center of the runway and provides alignment guidance
during takeoff and landings. The centerline consists of a line of
uniformly spaced stripes and gaps.
Aiming Point Marking. The aiming point
marking serves as a visual aiming point for a landing aircraft. These
two rectangular markings consist of a broad white stripe located on
each side of the runway centerline and approximately 1,000 feet from
the landing threshold, as shown in FIG 2-3-1, Precision Instrument
Touchdown Zone Markers. The touchdown zone
markings identify the touchdown zone for landing operations and are
coded to provide distance information in 500 feet (150m) increments.
These markings consist of groups of one, two, and three rectangular
bars symmetrically arranged in pairs about the runway centerline, as
shown in FIG 2-3-1, Precision Instrument Runway Markings. For runways
having touchdown zone markings on both ends, those pairs of markings
which extend to within 900 feet (270m) of the midpoint between the
thresholds are eliminated.
Instrument Runway and
Visual Runway Markings
f. Runway Side
Stripe Marking. Runway side stripes
delineate the edges of the runway. They provide a visual contrast
between runway and the abutting terrain or shoulders. Side stripes
consist of continuous white stripes located, on each side of the
runway as shown in FIG 2-3-4.
Shoulder Markings. Runway shoulder stripes
may be used to supplement runway side stripes to identify pavement
areas contiguous to the runway sides that are not intended for use by
aircraft. Runway Shoulder stripes are Yellow.
(See FIG 2-3-5.)
Threshold Markings. Runway threshold
markings come in two configurations. They either consist of eight
longitudinal stripes of uniform dimensions disposed symmetrically
about the runway centerline, as shown in FIG 2-3-1, or the number of
stripes is related to the runway width as indicated in TBL 2-3-2. A
threshold marking helps identify the beginning of the runway that is
available for landing. In some instances the landing threshold may be
relocated or displaced.
of a Threshold. Sometimes
construction, maintenance, or other activities require the threshold
to be relocated towards the rollout end of the runway. (See FIG
2-3-3.) When a threshold is relocated, it closes not only a set
portion of the approach end of a runway, but also shortens the
length of the opposite direction runway. In these cases, a NOTAM
should be issued by the airport operator identifying the portion of
the runway that is closed, e.g., 10/28 W 900 CLSD. Because the
duration of the relocation can vary from a few hours to several
months, methods identifying the new threshold may vary. One common
practice is to use a ten feet wide white threshold bar across the
width of the runway. Although the runway lights in the area between
the old threshold and new threshold will not be illuminated, the
runway markings in this area may or may not be obliterated, removed,
Threshold. A displaced threshold is a
threshold located at a point on the runway other than the designated
beginning of the runway. Displacement of a threshold reduces the
length of runway available for landings. The portion of runway
behind a displaced threshold is available for takeoffs in either
direction and landings from the opposite direction. A ten feet wide
white threshold bar is located across the width of the runway at the
displaced threshold. White arrows are located along the centerline
in the area between the beginning of the runway and displaced
threshold. White arrow heads are located across the width of the
runway just prior to the threshold bar, as shown in FIG 2-3-4.
Airport operator. When reporting the relocation or displacement of a
threshold, the airport operator should avoid language which confuses
Number of Runway Threshold
60 feet (18 m)
75 feet (23 m)
100 feet (30 m)
150 feet (45 m)
200 feet (60 m)
Relocation of a
Threshold with Markings for
Taxiway Aligned with Runway
Bar. A demarcation bar delineates a runway
with a displaced threshold from a blast pad, stopway or taxiway that
precedes the runway. A demarcation bar is 3 feet (1m) wide and yellow,
since it is not located on the runway as shown in FIG 2-3-6.
These markings are used to show pavement
areas aligned with the runway that are unusable for landing,
takeoff, and taxiing. Chevrons are yellow. (See FIG 2-3-7.)
Threshold Bar. A threshold bar delineates
the beginning of the runway that is available for landing when the
threshold has been relocated or displaced. A threshold bar is 10 feet
(3m) in width and extends across the width of the runway, as shown in
2-3-4. Taxiway Markings
All taxiways should have centerline markings
and runway holding position markings whenever they intersect a runway.
Taxiway edge markings are present whenever there is a need to separate
the taxiway from a pavement that is not intended for aircraft use or
to delineate the edge of the taxiway. Taxiways may also have shoulder
markings and holding position markings for Instrument Landing
System/Microwave Landing System (ILS/MLS) critical areas, and
taxiway/taxiway intersection markings.
AIM, Holding Position Markings, Paragraph 2-3-5.
Centerline. The taxiway centerline is a
single continuous yellow line, 6 inches (15 cm) to 12 inches (30 cm)
in width. This provides a visual cue to permit taxiing along a
designated path. Ideally the aircraft should be kept centered over
this line during taxi to ensure wing-tip clearance.
(See FIG 2-3-8.)
c. Taxiway Edge
Markings. Taxiway edge markings are used to
define the edge of the taxiway. They are primarily used when the
taxiway edge does not correspond with the edge of the pavement. There
are two types of markings depending upon whether the aircraft is
suppose to cross the taxiway edge:
Markings. These consist of a
continuous double yellow line, with each line being at least 6
inches (15 cm) in width spaced 6 inches (15 cm) apart. They are used
to define the taxiway edge from the shoulder or some other abutting
paved surface not intended for use by aircraft.
Markings. These markings are used when
there is an operational need to define the edge of a taxiway or
taxilane on a paved surface where the adjoining pavement to the
taxiway edge is intended for use by aircraft. e.g., an apron. Dashed
taxiway edge markings consist of a broken double yellow line, with
each line being at least 6 inches (15 cm) in width, spaced 6 inches
(15 cm) apart (edge to edge). These lines are 15 feet (4.5 m) in
length with 25 foot (7.5 m) gaps. (See FIG 2-3-9.)
Shoulder Markings. Taxiways, holding bays,
and aprons are sometimes provided with paved shoulders to prevent
blast and water erosion. Although shoulders may have the appearance of
full strength pavement they are not intended for use by aircraft, and
may be unable to support an aircraft. Usually the taxiway edge marking
will define this area. Where conditions exist such as islands or
taxiway curves that may cause confusion as to which side of the edge
stripe is for use by aircraft, taxiway shoulder markings may be used
to indicate the pavement is unusable. Taxiway shoulder markings are
yellow. (See FIG 2-3-10.)
Blast Pad or Stopway or Taxiway
Preceding a Displaced Threshold
Blast Pads and Stopways
e. Surface Painted Taxiway Direction Signs. Surface painted
taxiway direction signs have a yellow background with a black
inscription, and are provided when it is not possible to provide
taxiway direction signs at intersections, or when necessary to
supplement such signs. These markings are located adjacent to the
centerline with signs indicating turns to the left being on the left
side of the taxiway centerline and signs indicating turns to the right
being on the right side of the centerline. (See FIG 2-3-11.)
Painted Location Signs. Surface painted
location signs have a black background with a yellow inscription. When
necessary, these markings are used to supplement location signs
located along side the taxiway and assist the pilot in confirming the
designation of the taxiway on which the aircraft is located. These
markings are located on the right side of the centerline. (See FIG
Position Markings. These markings are
located at points along low visibility taxi routes designated in the
airport's Surface Movement Guidance Control System (SMGCS) plan. They
are used to identify the location of taxiing aircraft during low
visibility operations. Low visibility operations are those that occur
when the runway visible range (RVR) is below 1200 feet(360m). They are
positioned to the left of the taxiway centerline in the direction of
taxiing. (See FIG 2-3-12.) The geographic position marking is a circle
comprised of an outer black ring contiguous to a white ring with a
pink circle in the middle. When installed on asphalt or other
dark-colored pavements, the white ring and the black ring are
reversed, i.e., the white ring becomes the outer ring and the black
ring becomes the inner ring. It is designated with either a number or
a number and letter. The number corresponds to the consecutive
position of the marking on the route.
2-3-5. Holding Position Markings
Holding Position Markings. For runways these
markings indicate where an aircraft is supposed to stop. They consist
of four yellow lines two solid, and two dashed, spaced six or twelve
inches apart and extending across the width of the taxiway or runway.
The solid lines are always on the side where the aircraft is to hold.
There are three locations where runway holding position markings are
Holding Position Markings on Taxiways.
These markings identify the locations on a taxiway where an aircraft
is supposed to stop when it does not have clearance to proceed onto
the runway. The runway holding position markings are shown in FIG
2-3-13 and FIG 2-3-16. When instructed by
ATC "Hold short of (runway "xx")" the pilot should stop so no part
of the aircraft extends beyond the holding position marking. When
approaching the holding position marking, a pilot should not cross
the marking without ATC clearance at a controlled airport or without
making sure of adequate separation from other aircraft at
uncontrolled airports. An aircraft exiting a runway is not clear of
the runway until all parts of the aircraft have crossed the
applicable holding position marking.
Holding Position Markings on Runways.
These markings are installed on runways only if the
runway is normally used by air traffic control for "land, hold
short" operations or taxiing operations and have operational
significance only for those two types of operations. A sign with a
white inscription on a red background is installed adjacent to these
holding position markings. (See FIG 2-3-14.) The holding position
markings are placed on runways prior to the intersection with
another runway, or some designated point. Pilots receiving
instructions "cleared to land, runway "xx"" from air traffic control
are authorized to use the entire landing length of the runway and
should disregard any holding position markings located on the
runway. Pilots receiving and accepting instructions "cleared to land
runway "xx," hold short of runway "yy"" from air traffic control
must either exit runway "xx," or stop at the holding position prior
to runway "yy."
Located in Runway Approach Areas.
These markings are used at some airports where it is necessary to
hold an aircraft on a taxiway located in the approach or departure
area of a runway so that the aircraft does not interfere with the
operations on that runway. This marking is collocated with the
runway approach area holding position sign. (See subparagraph
2-3-8b2, Runway Approach Area Holding Position Sign, and FIG
Position Markings for Instrument Landing System (ILS).
Holding position markings for ILS/MLS critical areas
consist of two yellow solid lines spaced two feet apart connected by
pairs of solid lines spaced ten feet apart extending across the width
of the taxiway as shown. (See FIG 2-3-16.) A sign with an inscription
in white on a red background is installed adjacent to these hold
position markings. When the ILS critical area is being protected, the
pilot should stop so no part of the aircraft extends beyond the
holding position marking. When approaching the holding position
marking, a pilot should not cross the marking without ATC clearance.
ILS critical area is not clear until all parts of the aircraft have
crossed the applicable holding position marking.
AIM, Instrument Landing System (ILS), Paragraph 1-1-9.
Position Markings for Taxiway/ Taxiway Intersections.
Holding position markings for taxiway/taxiway intersections consist of
a single dashed line extending across the width of the taxiway as
shown. (See FIG 2-3-17.) They are installed on taxiways where air
traffic control normally holds aircraft short of a taxiway
intersection. When instructed by ATC "hold short of (taxiway)" the
pilot should stop so no part of the aircraft extends beyond the
holding position marking. When the marking is not present the pilot
should stop the aircraft at a point which provides adequate clearance
from an aircraft on the intersecting taxiway.
Painted Holding Position Signs.
painted holding position signs have a red background with a white
inscription and supplement the signs located at the holding position.
This type of marking is normally used where the width of the holding
position on the taxiway is greater than 200 feet(60m). It is located
to the left side of the taxiway centerline on the holding side and
prior to the holding position marking. (See FIG 2-3-11.)
Position Markings on Taxiway
Position Markings on Runways
Located in Runway Approach Area
click to enlarge
Position Markings: ILS Critical Area
2-3-6. Other Markings
Roadway Markings. The vehicle roadway
markings are used when necessary to define a pathway for vehicle
operations on or crossing areas that are also intended for aircraft.
These markings consist of a white solid line to delineate each edge of
the roadway and a dashed line to separate lanes within the edges of
the roadway. In lieu of the solid lines, zipper markings may be used
to delineate the edges of the vehicle roadway. (See FIG 2-3-18.)
Details of the zipper markings are shown in FIG 2-3-19.
b. VOR Receiver
Checkpoint Markings. The VOR receiver
checkpoint marking allows the pilot to check aircraft instruments with
navigational aid signals. It consists of a painted circle with an
arrow in the middle; the arrow is aligned in the direction of the
checkpoint azimuth. This marking, and an associated sign, is located
on the airport apron or taxiway at a point selected for easy access by
aircraft but where other airport traffic is not to be unduly
obstructed. (See FIG 2-3-20.)
The associated sign contains the VOR station identification letter and
course selected (published) for the check, the words "VOR check
course," and DME data (when applicable). The color of the letters and
numerals are black on a yellow background.
VOR check course
Stripes, White, Zipper Style
Area Boundary Markings. These markings
delineate the movement area, i.e., area under air traffic control.
These markings are yellow and located on the boundary between the
movement and nonmovement area. The nonmovement area boundary markings
consist of two yellow lines (one solid and one dashed) 6 inches (15cm)
in width. The solid line is located on the nonmovement area side while
the dashed yellow line is located on the movement area side. The
nonmovement boundary marking area is shown in FIG 2-3-21.
Area Boundary Markings
Closed or Temporarily
and Taxiway Markings
d. Marking and Lighting of Permanently Closed Runways and Taxiways.
For runways and taxiways which are permanently closed, the lighting
circuits will be disconnected. The runway threshold, runway
designation, and touchdown markings are obliterated and yellow crosses
are placed at each end of the runway and at 1,000 foot intervals. (See
Temporarily Closed Runways and Taxiways.
To provide a visual indication to pilots that a runway is
temporarily closed, crosses are placed on the runway only at each end
of the runway. The crosses are yellow in color. (See FIG 2-3-22.)
A raised lighted yellow cross may be placed on
each runway end in lieu of the markings described in subparagraph
e,Temporarily Closed Runways and Taxiways, to indicate the runway is
A visual indication may not be present depending
on the reason for the closure, duration of the closure, airfield
configuration and the existence and the hours of operation of an
airport traffic control tower. Pilots should check NOTAM's and the
Automated Terminal Information System (ATIS) for local runway and
taxiway closure information.
Temporarily closed taxiways are usually treated
as hazardous areas, in which no part of an aircraft may enter, and
are blocked with barricades. However, as an alternative a yellow
cross may be installed at each entrance to the taxiway.
Landing Areas. The markings
illustrated in FIG 2-3-23 are used to identify the landing and takeoff
area at a public use heliport and hospital heliport. The letter "H" in
the markings is oriented to align with the intended direction of
approach. FIG 2-3-23 also depicts the markings for a closed airport.
2-3-7. Airport Signs
There are six types of
signs installed on airfields: mandatory instruction signs, location
signs, direction signs, destination signs, information signs, and runway
distance remaining signs. The characteristics and use of these signs are
discussed in paragraph 2-3-8, Mandatory Instruction Signs, through
paragraph 2-3-13, Runway Distance Remaining Signs.
AC150/5340-18, Standards for Airport Sign Systems for Detailed
Information on Airport Signs.
Position Sign at Beginning of Takeoff Runway
2-3-8. Mandatory Instruction
These signs have a red background with a white
inscription and are used to denote:
An entrance to a runway or critical area and;
Areas where an aircraft is prohibited from
Typical mandatory signs and applications are:
Holding Position Sign. This sign is
located at the holding position on taxiways that intersect a runway
or on runways that intersect other runways. The inscription on the
sign contains the designation of the intersecting runway as shown in
FIG 2-3-24. The runway numbers on the sign are arranged to
correspond to the respective runway threshold. For example, "15-33"
indicates that the threshold for Runway 15 is to the left and the
threshold for Runway 33 is to the right.
On taxiways that intersect the beginning of the
takeoff runway, only the designation of the takeoff runway may
appear on the sign as shown in FIG 2-3-25, while all other signs
will have the designation of both runway directions.
Position Sign for a Taxiway that Intersects
the Intersection of Two Runways
Position Sign for a Runway Approach Area
(b) If the sign is located on a taxiway
that intersects the intersection of two runways, the designations
for both runways will be shown on the sign along with arrows
showing the approximate alignment of each runway as shown in FIG
2-3-26. In addition to showing the approximate runway alignment,
the arrow indicates the direction to the threshold of the runway
whose designation is immediately next to the arrow.
A runway holding position sign on a taxiway
will be installed adjacent to holding position markings on the
taxiway pavement. On runways, holding position markings will be
located only on the runway pavement adjacent to the sign, if the
runway is normally used by air traffic control for "Land, Hold
Short" operations or as a taxiway. The holding position markings
are described in paragraph 2-3-5, Holding Position Markings.
Runway Approach Area Holding Position Sign.
At some airports, it is necessary to hold an aircraft
on a taxiway located in the approach or departure area for a runway
so that the aircraft does not interfere with operations on that
runway. In these situations, a sign with the designation of the
approach end of the runway followed by a "dash" (-) and letters
"APCH" will be located at the holding position on the taxiway.
Holding position markings in accordance with paragraph 2-3-5,
Holding Position Markings, will be located on the taxiway pavement.
An example of this sign is shown in FIG 2-3-27. In this example, the
sign may protect the approach to Runway 15 and/or the departure for
Position Sign for ILS Critical Area
Prohibiting Aircraft Entry into an Area
3. ILS Critical Area Holding Position Sign.
At some airports, when the instrument landing system
is being used, it is necessary to hold an aircraft on a taxiway at a
location other than the holding position described in paragraph
2-3-5, Holding Position Markings. In these situations the holding
position sign for these operations will have the inscription "ILS"
and be located adjacent to the holding position marking on the
taxiway described in paragraph 2-3-5. An example of this sign is
shown in FIG 2-3-28.
4. No Entry
Sign. This sign, shown in FIG
2-3-29, prohibits an aircraft from entering an area. Typically, this
sign would be located on a taxiway intended to be used in only one
direction or at the intersection of vehicle roadways with runways,
taxiways or aprons where the roadway may be mistaken as a taxiway or
other aircraft movement surface.
The holding position sign provides the pilot with a visual cue as to
the location of the holding position marking. The operational
significance of holding position markings are described in the notes
for paragraph 2-3-5, Holding Position Markings.
Location Sign Collocated with
Runway Holding Position Sign
2-3-9. Location Signs
Location signs are used to identify either a taxiway or
runway on which the aircraft is located. Other location signs provide
a visual cue to pilots to assist them in determining when they have
exited an area. The various location signs are described below.
Location Sign. This sign has a
black background with a yellow inscription and yellow border as
shown in FIG 2-3-30. The inscription is the designation of the
taxiway on which the aircraft is located. These signs are installed
along taxiways either by themselves or in conjunction with direction
signs or runway holding position signs.
(See FIG 2-3-35 and FIG 2-3-31.)
Location Sign. This sign has a
black background with a yellow inscription and yellow border as
shown in FIG 2-3-32. The inscription is the designation of the
runway on which the aircraft is located. These signs are intended to
complement the information available to pilots through their
magnetic compass and typically are installed where the proximity of
two or more runways to one another could cause pilots to be confused
as to which runway they are on.
Boundary Sign. This sign has a
yellow background with a black inscription with a graphic depicting
the pavement holding position marking as shown in FIG 2-3-33. This
sign, which faces the runway and is visible to the pilot exiting the
runway, is located adjacent to the holding position marking on the
pavement. The sign is intended to provide pilots with another visual
cue which they can use as a guide in deciding when they are "clear
of the runway."
Area Boundary Sign
Critical Area Boundary Sign.
This sign has
a yellow background with a black inscription with a graphic
depicting the ILS pavement holding position marking as shown in FIG
2-3-34. This sign is located adjacent to the ILS holding position
marking on the pavement and can be seen by pilots leaving the
critical area. The sign is intended to provide pilots with another
visual cue which they can use as a guide in deciding when they are
"clear of the ILS critical area."
2-3-10. Direction Signs
Direction signs have a yellow background with a black
inscription. The inscription identifies the designation(s) of the
intersecting taxiway(s) leading out of the intersection that a pilot
would normally be expected to turn onto or hold short of. Each
designation is accompanied by an arrow indicating the direction of the
Except as noted in subparagraph e, each taxiway
designation shown on the sign is accompanied by only one arrow. When
more than one taxiway designation is shown on the sign each
designation and its associated arrow is separated from the other
taxiway designations by either a vertical message divider or a taxiway
location sign as shown in FIG 2-3-35.
Direction signs are normally located on the left prior
to the intersection. When used on a runway to indicate an exit, the
sign is located on the same side of the runway as the exit. FIG 2-3-36
shows a direction sign used to indicate a runway exit.
The taxiway designations and their associated arrows on
the sign are arranged clockwise starting from the first taxiway on the
(See FIG 2-3-35.)
If a location sign is located with the
direction signs, it is placed so that the designations for all turns
to the left will be to the left of the location sign; the designations
for continuing straight ahead or for all turns to the right would be
located to the right of the location sign. (See FIG 2-3-35.)
When the intersection is comprised of only one crossing
taxiway, it is permissible to have two arrows associated with the
crossing taxiway as shown in FIG 2-3-37. In this case, the location
sign is located to the left of the direction sign.
Array with Location Sign
on Far Side of Intersection
for Runway Exit
Array for Simple Intersection
Sign for Military Area
Sign for Common Taxiing Route
to Two Runways
2-3-11. Destination Signs
Destination signs also have a yellow background with a
black inscription indicating a destination on the airport. These signs
always have an arrow showing the direction of the taxiing route to
that destination. FIG 2-3-38 is an example of a typical destination
sign. When the arrow on the destination sign indicates a turn, the
sign is located prior to the intersection.
Destinations commonly shown on these types of signs
include runways, aprons, terminals, military areas, civil aviation
areas, cargo areas, international areas, and fixed base operators. An
abbreviation may be used as the inscription on the sign for some of
When the inscription for two or more destinations
having a common taxiing route are placed on a sign, the destinations
are separated by a "dot" (·) and one arrow would be used as shown in
FIG 2-3-39. When the inscription on a sign contains two or more
destinations having different taxiing routes, each destination will be
accompanied by an arrow and will be separated from the other
destinations on the sign with a vertical black message divider as
shown in FIG 2-3-40.
Sign for Different Taxiing Routes
to Two Runways
2-3-12. Information Signs
Information signs have a
yellow background with a black inscription. They are used to provide the
pilot with information on such things as areas that cannot be seen from
the control tower, applicable radio frequencies, and noise abatement
procedures. The airport operator determines the need, size, and location
for these signs.
Runway Distance Remaining Signs
Runway distance remaining
signs have a black background with a white numeral inscription and may
be installed along one or both side(s) of the runway. The number on the
signs indicates the distance (in thousands of feet) of landing runway
remaining. The last sign, i.e., the sign with the numeral "1," will be
located at least 950 feet from the runway end. FIG 2-3-41 shows an
example of a runway distance remaining sign.
Remaining Sign Indicating
3,000 feet of Runway Remaining
2-3-14. Aircraft Arresting Devices
Certain airports are equipped with a means of rapidly
stopping military aircraft on a runway. This equipment, normally
referred to as EMERGENCY ARRESTING GEAR, generally consists of pendant
cables supported over the runway surface by rubber "donuts." Although
most devices are located in the overrun areas, a few of these
arresting systems have cables stretched over the operational areas
near the ends of a runway.
Arresting cables which cross over a runway require
special markings on the runway to identify the cable location. These
markings consist of 10 feet diameter solid circles painted
"identification yellow," 30 feet on center, perpendicular to the
runway centerline across the entire runway width. Additional details
are contained in AC 150/5220-9, Aircraft Arresting Systems for Joint
Aircraft operations on the runway are not restricted by the
installation of aircraft arresting devices.