Like roads, which take us from our home to our destination, airports have taxiways which takes us to and from our runway
Along those roads (taxiways) exist a variety of markings and signs provide guidance to pilots operating on the airport surface during arrival and departure
These airport markings and signs, both in the United States and internationally, are standardized by the International Civil Aviation Organization (ICAO) to enhance safety and improve efficiency
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) are yellow
Runway Marking Elements
Runway Markings:
Runways Classification:
There are three types of runways, each with an associated level of markings: [Figure 1]
Visual Runways:
Visual runways are runways without an existing or planned instrument approach procedure
Visual runways are marked with the runway number and a dashed runway centerline [Figure 2]
Visual runways may also include threshold markings if intended for international operations
Aiming points may be included on runways 4,000' or longer used by jet aircraft
Non-Precision Runways:
Non-precision runways are runways with at least one end having a non-precision approach procedure
Non-precision runways do not incorporate an electric glide slope and the corresponding runway markings vary accordingly [Figure 3]
In many cases however, non-precision runways will look similar to visual runways
If your answer comes out to be greater than 360, or negative, then you added when you should have subtracted or vice versa
Parallel runways are designated with numbers but also as "L," "C," and/or "R" which stand for left, center, and/or right
Example: 21L, 21C, and/or 21R
When there are only 2 parallel runways, the "center" is omitted and only "left" and "right" is used
When multiple parallel runways at the same airport are separated by a large distance, such as by a central terminal or several terminals, the runways may be designated as non-parallel runways to avoid pilot confusion
Note wind directions are reported in degrees magnetic, to provide an applicable reference to the runway direction
Runway Markings
Runway Centerline Marking:
Runway Centerline Markings
Runway centerline markings identify the center of the runway for guidance on takeoff and landing [Figure 6]
Painted white in color
One centerline marking is 120' in length and the gap between markings is 80' giving 200' for a full set
Runway Centerline Markings
Runway Aim Point
Runway Aiming Point:
Aiming point markers serve as a visual target for landing aircraft [Figure 7]
Consists of two broad white stripes located on each side of the runway, about 1,000' from the landing threshold
Runway Aim Point
Runway Touchdown Zone Markings
Runway Touchdown Zone Markings:
Thin white stripes identifying the touchdown zone for landing operations and are spaced in 500' (150m) increments [Figure 8]
Three, two and then one thin striped symmetrical bars arranged in pairs on each side of runway centerline
For runways having touchdown zone markings on both ends, those pairs of markings which extend to within 900' (270m) of the midpoint between the thresholds are eliminated
Runway Touchdown Zone Markings
Runway Side Stripe Markings:
Runway Side Stripe Markings
White lines identifying the edges of the runway provide visual contrast between runway and the abutting terrain or shoulders [Figure 9]
Runway Side Stripe Markings
Runway Shoulder Markings:
Yellow lines may supplement runway side stripes to identify pavement areas adjacent to the runway sides that are not intended for use by aircraft
Runway Threshold Markings:
Runway Threshold Markings
Runway threshold markings identify the beginning of the runway that is available for landing and come in two configurations:
They either consist of eight longitudinal stripes of uniform dimensions disposed symmetrically about the runway centerline, or the number of stripes is related to the runway width [Figure 10]
When the stripes that correspond to the width of the runway:
4 stripes = 60' wide
6 stripes = 75' wide
8 stripes = 100' wide
12 stripes = 150' wide
16 stripes = 200' wide
In some instances the landing threshold may be relocated or displaced
Runway Threshold Markings
Displaced Threshold
Displaced Threshold:
A displaced threshold is a threshold located at a point on the runway other than the designated beginning of the runway [Figure 11]
Displacement of a threshold usually exists because of obstructions
Displacement of a threshold therefore reduces the length of runway available for landings
The portion of runway behind a displaced threshold is available for taxi, takeoff, and landing rollout however, it may not be used for runway touchdown
Exists usually because of obstructions
On runways with a displaced threshold, the beginning of the landing zone is marked by a 10' solid white line
White arrows are located along the centerline in the area between the beginning of the runway and displaced threshold
Demarcation bar separates the displaced threshold area from a blast pad, stop way, or taxiway that precedes the runway
Displaced Threshold
Relocated Runway Threshold
Relocated Runway Threshold:
Due to construction, maintenance, or other activities, a threshold may be closed/moved for a varied amount of time
When the threshold is relocated, the closed portion of the runway is not available for use by aircraft for takeoff or landing, but it is available for taxi
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
Closure will be noted via Notice to Air Missions (NOTAM) (for example, 10/28 W 900 CLSD), but the method of marking may vary
Methods of identifying the new threshold may vary with 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, or covered
Yellow arrow heads are placed across the width of the runway just prior to the threshold bar [Figure 12]
Demarcation Bar:
Delineates a runway with a displayed threshold from a blast pad, stop-way or taxiway that precedes the runway
The demarcation bar is 3' (1m) wide and yellow, since it is not located on the runway
Chevrons:
Used to show pavement areas aligned with the runway that are unusable for landing, takeoff, and taxiing
Chevrons are yellow
Runway Threshold Bar:
Delineates the beginning of the runway that is available for landing when the threshold has been displayed or relocated
A 10' (3M) wide bar extends across the width of the runway
Blast-pad/Stop-way:
Blast-pad/Stop-way
Referred to as an overrun and may be used as such [Figure 13]
Cannot be used for normal operation
Allows propeller or jet blasts to safely dissipate
Blast-pad/Stop-way
Runway Safety Area:
The runway safety area (RSA) is a defined surface surrounding the runway prepared, or suitable, for reducing the risk of damage to airplanes in the event of an undershoot, overshoot, or excursion from the runway
The dimensions of the RSA vary and can be determined by using the criteria contained within AC 150/5300-13, Airport Design, Chapter 3
Figure 3-1 in AC 150/5300-13 depicts the RSA
Additionally, it provides greater accessibility for firefighting and rescue equipment in emergency situations
The RSA is typically graded and mowed
The lateral boundaries are usually identified by the presence of the runway holding position signs and markings on the adjoining taxiway stubs
Aircraft should not enter the RSA without making sure of adequate separation from other aircraft during operations at uncontrolled airports
Taxiway Markings:
Centerline Markings:
Continuous Centerline
Enhanced Taxiway Centerline
Centerline markings provide a visual cue to permit taxiing along a designated path
Ideally, pilots should maintain centerline but be aware, this does not guarantee wingtip clearance of obstacles on either side
Two Types of Taxiway Centerline Markings:
Normal Taxiway Centerline:
Normal taxiway centerlines consist of a single continuous yellow line, 6 inches (15 cm) to 12 inches (30 cm) in width [Figure 14]
Enhanced Taxiway Centerline:
At some airports, mostly the larger commercial service airports, an enhanced taxiway centerline will be used
The enhanced taxiway centerline marking consists of a parallel line of yellow dashes on either side of the normal taxiway centerline
Taxiway centerlines are enhanced for a maximum of 150 feet prior to a runway holding position marking as a warning to pilots that he/she is approaching a runway holding position marking and should prepare to stop unless he/she has been cleared onto or across the runway by ATC [Figure 15]
Enhanced Taxiway Centerline
Note that taxiway markings are present on runways to guide pilots off the runway onto a taxiway
Taxiway markings are absent at runway intersections to avoid pilots accidentally taxing off one runway onto another
Taxiway Edge Markings:
Taxiway Edge Markings
Taxiway edge markings are used to define the edge of the taxiway; used primarily when the edge of the pavement and taxiway do not correspond
Two Types of Taxiway Edge Markings:
Continuous Markings:
Consist of a double yellow line, each 6 inches (15cm) in width, separated by 6 inches [Figure 16]
These continuous markings delineate areas where aircraft operation is not intended
Dashed 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
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' (4.5m) in length with 25' (7.5m) gaps [Figure 16]
Taxiway Edge Markings
Taxi Shoulder Markings:
Taxi Shoulder Markings
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
In these areas, taxiway shoulder markings are used to indicate the pavement is unusable
Examples: taxiways, holding bays, and aprons are sometimes provided with paved shoulders to prevent blast and water erosion which are not intended for use by aircraft
Used 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 [Figure 17]
Consists of yellow lines perpendicular to the taxiway edge markings
Surface Painted Taxiway Direction Signs:
Written with yellow background with black inscription
Provided when it is not possible to provide taxiway direction signs at intersections, or when necessary to supplement
Located adjacent to the centerline on the side the turn is to be executed to [Figure 18]
Turns to the left being on the left side of the taxiway centerline, right being on the right side
Surface Painted Location Signs:
Written with a black background and yellow inscription
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, on the right side of centerline [Figure 18]
Surface Painted Signs
Geographic Position Markings:
Located at points along low visibility taxi routes designated in the airport's Surface Movement Guidance Control System (SMGCS) plan [Figure 19]
Identifies the location of taxiing aircraft when Runway Visual Range (RVR) is below 1200' (360m)
Positioned to the left of the centerline in the direction of taxi
Comprise of a black circle contiguous to a white ring with a pink circle in the middle
The white and black ring are reversed when painted on blacktop to make it easy to read
Designated with a number or a number and letter to correspond to the consecutive position of the marking on the route
Geographic Position Markings
Hold Position Markings:
Runway Holding Position Markings:
Runway hold positions signs denote the designation of an intersecting runway
For runways, these markings indicate where aircraft MUST STOP when approaching a runway
Generally placed between 125-250' from the runway centerline
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
The solid lines are always on the side where the aircraft is to hold
There are three locations where runway holding position markings are encountered
Runway Holding Position Markings on Taxiways:
These markings identify the locations on a taxiway where aircraft MUST STOP when a clearance has not been issued to proceed onto the runway [Figure 20/21]
Holding Position Markings: ILS Critical AreaHolding Position Markings: ILS Critical Area
Generally, runway holding position markings also identify the boundary of the runway safety area (RSA) for aircraft exiting the runway
When instructed by ATC, "Hold short of [Runway]," the pilot MUST STOP so that no part of the aircraft extends beyond the runway holding position marking
ATC will state "Cleared to cross [Runway]" when approved to proceed beyond the hold line
When approaching runways at airports with an operating control tower, pilots must not cross the runway holding position marking without ATC clearance
Pilots approaching runways at airports without an operating control tower must ensure adequate separation from other aircraft, vehicles, and pedestrians prior to crossing the holding position markings
An aircraft exiting a runway is not clear of the runway until all parts of the aircraft have crossed the applicable holding position marking
Runway Holding Position Markings on Taxiway
Runway Holding Position Markings on Runways:
These markings identify the locations on runways where aircraft MUST STOP
These markings are located on runways used by ATC for Land And Hold Short Operations and Taxiing operations
For taxiing operations, the pilot MUST STOP prior to the holding position markings unless explicitly authorized to cross by ATC
A sign with a white inscription on a red background is located adjacent to these holding position markings [Figure 22]
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]" from ATC 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], hold short of [Runway]" from ATC must either exit [Runway] or stop at the holding position prior to the specific runway
Otherwise, pilots are authorized to use the entire landing length of the runway and disregard the holding position markings
Runway Holding Position Markings on Runway
Holding Position Markings on Taxiways 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 [Figure 23]
This marking is collocated with the runway approach area holding position sign
When specifically instructed by ATC "Hold short of [Runway Approach Area]" the pilot MUST STOP so that no part of the aircraft extends beyond the holding position marking
Taxiways Located in Runway Approach Area
Holding Position Markings for Instrument Landing System (ILS):
At airports equipped with an ILS, it is possible they will move the hold line back or create a ILS hold line for that type of operation
Holding position markings for ILS 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 [Figure 20]
A sign with an inscription in white on a red background is located adjacent to these hold position markings [Figure 34]
When instructed by ATC to hold short of the ILS critical area, pilots MUST STOP so that no part of the aircraft extends beyond the holding position marking
When approaching the holding position marking, pilots must not cross the marking without ATC clearance
The ILS critical area is not clear until all parts of the aircraft have crossed the applicable holding position marking
Holding Position Markings for Intersecting Taxiways:
Holding Position Markings: Taxiway/Taxiway Intersections
Holding position markings for taxiway/taxiway intersections consist of a single dashed line extending across the width of the taxiway [Figure 24]
They are located on taxiways where ATC holds aircraft short of a taxiway intersection
When instructed by ATC "hold short of [Taxiway]" the pilot MUST STOP so that no part of the aircraft extends beyond the holding position marking
When the marking is not present, the pilot MUST STOP the aircraft at a point which provides adequate clearance from an aircraft on the intersecting taxiway
Surface Painted Holding Position Signs:
Surface 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' (60m)
It is located to the left side of the taxiway centerline on the holding side and prior to the holding position marking [Figure 18]
Other Markings:
Vehicle Roadway Markings:
Vehicle Roadway Markings
Roadway Edge Stripes, White, Zipper Style
Used when necessary to define a pathway for vehicle operations on or crossing areas that are also intended for aircraft
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 [Figure 25]
Details of the zipper markings are shown in [Figure 26]
Vehicle Roadway Markings
Very-High Omni-Directional Range (VOR) Receiver Checkpoint Markings:
The VOR receiver checkpoint marking allows the pilot to check aircraft instruments with navigational aid signals
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 [Figure 27]
The associated sign contains the VOR station identification letter and course selected (published) for the check, the words "VOR check course," and Distance Measuring Equipment (DME) data (when applicable) using black numerals on a yellow background
The color of the letters and numerals are black on a yellow background
These locations on the airfield and information about them can be found in the Chart Supplement U.S.
These markings delineate the movement area, i.e., area under ATC
These markings are yellow and located on the boundary between the movement and non-movement area
The non-movement 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 non-movement area side while the dashed yellow line is located on the movement area side [Figure 28]
Non-movement Area Boundary Markings
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' intervals
Temporarily Closed Runways and Taxiways:
To provide a visual indication to pilots that a runway is temporarily closed, yellow "Xs" are placed on the runway only at each end of the runway [Figure 29]
A raised lighted yellow cross may be placed on each runway end in lieu of permanent markings to indicate the runway is closed
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 NOTAMs 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
Depending on the reason for the closure, duration of closure, airfield configuration, and the existence and the hours of operation of an ATC tower, a visual indication may not be present
You must always check NOTAMs and ATIS for runway and taxiway closure information
Air traffic control towers are not permitted to issue a taxi clearance for a closed runway
Closed Taxiway or Runway Marking, Day/Night
Special Purpose Areas:
Closed or overrun stop way areas are special purpose areas
Any surface or area which appears usable, but which, due to the nature of its structure, is unusable
See EMAS below
Short Takeoff and Landing:
Short takeoff and landing (STOL) runways will have STOL painted on the approach end
Helicopter Landing Areas:
Used to identify the landing and takeoff area at a public use heliport and hospital heliport [Figure 30]
The letter "H" in the markings is oriented to align with the intended direction of approach
Helicopter Landing Areas
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
Mandatory Instruction Signs:
Mandatory signs have a red background with a white inscription used to denote an entrance to a runway or critical area and areas where an aircraft is prohibited from entering
Note that holding position signs provides the pilot with a visual cue as to the location of the holding position marking
Runway Holding Position Sign:
Runway Holding Position Sign
Holding Position Sign at Beginning of Takeoff Runway
This sign is located at the holding position on taxiways that intersect a runway or on runways that intersect other runways and contains the designation of the intersecting runway [Figure 31]
Runway numbers are arranged to correspond to the respective runway threshold
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 [Figure 32]
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 [Figure 33]
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
Runway Approach Area Holding Position Sign:
Holding Position Sign for a Taxiway that Intersects the Intersection of Two Runways
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 [Figure 34]
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 will be located on the taxiway pavement
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 [Figure 35]
Holding Position Sign for ILS Critical Area
No Entry Sign:
Prohibits an aircraft from entering an area typically, 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 [Figure 36]
Sign Prohibiting Aircraft Entry into an Area
Location Signs:
Identify either the taxiway or runway where your aircraft is located
Other location signs provide a visual cue to pilots to assist them in determining when they are entering/exiting an area
Taxiway Location Sign:
Has a black background with a yellow inscription and yellow border [Figure 37]
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 [Figure 38/41]
Taxiway Location Sign
Taxiway Location Sign Collocated with Runway Holding Position Sign
Runway Location Sign:
Utilizes a black background with a yellow inscription and yellow border as shown in [Figure 38]
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
Runway Boundary Sign:
The sign has a yellow background with a black inscription with a graphic depicting the pavement holding position marking as shown in [Figure 39]
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"
Runway Boundary Sign
ILS Critical Area Boundary Sign:
The sign has a yellow background with a black inscription with a graphic depicting the ILS pavement holding position marking as shown in [Figure 40]
The 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 a visual cue ensure "clear of the ILS critical area"
ILS Critical Area Boundary Sign
Aircraft and vehicle access to the ILS critical area must be controlled (by ATC) to ensure the integrity of ILS course signals whenever the official weather observation is a ceiling of less than 800 feet or visibility less than 2 miles
It is advisable at non-towered locations to observe the same restriction
Direction Signs:
Direction Sign Array with Location Sign on Far Side of Intersection
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 turn
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 [Figure 41]
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 [Figure 43]
The taxiway designations and their associated arrows on the sign are arranged clockwise starting from the first taxiway on the pilot's left [Figure 45]
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
When the intersection is comprised of only one crossing taxiway, it is permissible to have two arrows associated with the crossing taxiway [Figure 42/46]
In this case, the location sign is located to the left of the direction sign
Direction Sign Array for Simple Intersection
Direction Sign for Runway Exit
Destination Signs:
Destination Sign for Military Area
Destination Sign for Common Taxiing Route to Two Runways
Destination Sign for Different Taxiing Routes to Two Runways
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 [Figure 44]
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 these destinations
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 is used as shown in [Figure 43]
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 [Figure 44]
Destination Sign for Military Area
Destination Sign for Common Taxiing Route to Two Runways
Destination Sign for Different Taxiing Routes to Two Runways
Information Signs:
Information signs have a yellow background with a black inscription
Advise pilots of information such as areas that cannot be seen from the control tower, applicable radio frequencies, and procedures
The airport operator determines the need, size, and location for these signs
Runway Distance Remaining Signs:
Distance Remaining Sign
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 [Figure 47]
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
Use of Runway Half-way Signs at Unimproved Airports:
Typical Runway Half-way Sign
When installed, runway half-way signs provide the pilot with a reference point to judge takeoff acceleration trends
Assuming that the runway length is appropriate for takeoff (considering runway condition and slope, elevation, aircraft weight, wind, and temperature), typical takeoff acceleration should allow the airplane to reach 70% of lift-off airspeed by the midpoint of the runway
The "rule of thumb" is that should airplane acceleration not allow the airspeed to reach this value by the midpoint, the takeoff should be aborted, as it may not be possible to liftoff in the remaining runway
"Rule of Thumb" Considerations:
Airspeed indicators in small airplanes are not required to be evaluated at speeds below stalling, and may not be usable at 70% of liftoff airspeed
Based on a uniform surface condition
Puddles, soft spots, areas of tall and/or wet grass, loose gravel, upslope, winds etc., may impede acceleration or even cause deceleration
Even if the airplane achieves 70% of liftoff airspeed by the midpoint, the condition of the remainder of the runway may not allow further acceleration
The entire length of the runway should be inspected prior to takeoff to ensure a usable surface
Applies only to runway required for actual liftoff
In the event that obstacles affect the takeoff climb path, appropriate distance must be available after liftoff to accelerate to best angle of climb speed and to clear the obstacles
This will, in effect, require the airplane to accelerate to a higher speed by midpoint, particularly if the obstacles are close to the end of the runway
In addition, this technique does not take into account the effects of upslope or tailwinds on takeoff performance
These factors will also require greater acceleration than normal and, under some circumstances, prevent takeoff entirely
Use of this "rule of thumb" does not alleviate the pilot's responsibility to comply with applicable Federal Aviation Regulations, the limitations and performance data provided in the FAA approved Airplane Flight Manual (AFM), or, in the absence of an FAA approved AFM, other data provided by the aircraft manufacturer
In addition to their use during takeoff, runway half-way signs offer the pilot increased awareness of his or her position along the runway during landing operations
Note that there is no standardized symbology for a runway halfway sign [Figure 48]
Airport Markings & Signs Quick Reference Guide
Arresting Systems:
Certain military aircraft that are properly equipped can be rapidly stopped on a runway
Done with cables supported by rubber donuts
Solid yellow circles (10' diameter) 30' on center show location of cables
Engineered materials arresting systems (EMAS) constructed of high energy absorbing materials
Crush under the weight of commercial aircraft to slow them
Security Identification Display Areas, or SIDAs, are limited access areas that require a badge issued in accordance with procedures in CFR 49 Part 1542
A SIDA can include the Air Operations Area (AOA), e.g., aircraft movement area or parking area, or a Secured Area, such as where commercial passengers enplane
The AOA may not be a SIDA, but a Secured Area is always a SIDA. Movement through or into a SIDA is prohibited without authorization and proper identification being displayed
If you are unsure of the location of a SIDA, contact the airport authority for additional information
Airports that have a SIDA will have a description and map detailing boundaries and pertinent features available
Pilots or passengers without proper identification that are observed entering a SIDA may be reported to the Transportation Security Administration (TSA) or airport security and may be subject to civil and criminal fines and prosecution
Pilots are advised to brief passengers accordingly
Report suspicious activity to the TSA by calling AOPA's Airport Watch Program, 866-427-3287
49 CFR 1540 requires each individual who holds an airman certificate, medical certificate, authorization, or license issued by the FAA to present it for inspection upon a request from TSA
Sample Secuirty Identification Display Area (SIDA) Warning Sign
Use of Runways/Declared Distances:
Declared Distances Diagram
Declared Distances Constraints
Airport proprietors are responsible for taking the lead in local aviation noise control
Accordingly, they may propose specific noise abatement plans to the FAA which
If approved, these planns are applied in the form of Formal or Informal Runway Use Programs for noise abatement purposes
ATC will assign the runway/s most nearly aligned with the wind when 5 knots or more, or the "calm wind" runway when less than 5 knots unless:
Use of another runway is operationally advantageous, or
A Runway Use Program is in effect
Note Tailwind and crosswind considerations take precedence over delay/capacity considerations, and noise abatement operations/procedures
If a pilot prefers to use a runway different from that specified, the pilot is expected to advise ATC. ATC may honor such requests as soon as is operationally practicable
ATC will advise pilots when the requested runway is noise sensitive
When use of a runway other than the one assigned is requested, pilot cooperation is encouraged to preclude disruption of traffic flows or the creation of conflicting patterns
Declared Distances Diagram
Declared Distances:
Declared distances for a runway represent the maximum distances available and suitable for meeting takeoff and landing distance performance requirements
These distances are determined in accordance with FAA runway design standards by adding to the physical length of paved runway any clearway or stopway and subtracting from that sum any lengths necessary to obtain the standard runway safety areas, runway object free areas, or runway protection zones
As a result of these additions and subtractions, the declared distances for a runway may be more or less than the physical length of the runway as depicted on aeronautical charts and related publications, or available in electronic navigation databases provided by either the U.S. Government or commercial companies
All 14 CFR Part 139 airports report declared distances for each runway. Other airports may also report declared distances for a runway if necessary to meet runway design standards or to indicate the presence of a clearway or stopway. Where reported, declared distances for each runway end are published in the Chart Supplement U.S. For runways without published declared distances, the declared distances may be assumed to be equal to the physical length of the runway unless there is a displaced landing threshold, in which case the Landing Distance Available (LDA) is shortened by the amount of the threshold displacement
A "D" symbol is shown on U.S. Government charts to indicate that runway declared distance information is available (See appropriate Chart Supplement U.S., Alaska, or Pacific)
The FAA uses the following definitions for runway declared distances:
Takeoff Run Available (TORA):
The runway length declared available and suitable for the ground run of an airplane taking off
The TORA is typically the physical length of the runway, but it may be shorter than the runway length if necessary to satisfy runway design standards
For example, the TORA may be shorter than the runway length if a portion of the runway must be used to satisfy runway protection zone requirements
Takeoff Distance Available (TODA):
The takeoff run available plus the length of any remaining runway or clearway beyond the far end of the takeoff run available
The TODA is the distance declared available for satisfying takeoff distance requirements for airplanes where the certification and operating rules and available performance data allow for the consideration of a clearway in takeoff performance computations
The length of any available clearway will be included in the TODA published in the entry for that runway end within the Chart Supplement U.S.
Accelerate-Stop Distance Available (ASDA):
The runway plus stopway length declared available and suitable for the acceleration and deceleration of an airplane aborting a takeoff
The ASDA may be longer than the physical length of the runway when a stopway has been designated available by the airport operator, or it may be shorter than the physical length of the runway if necessary to use a portion of the runway to satisfy runway design standards; for example, where the airport operator uses a portion of the runway to achieve the runway safety area requirement
ASDA is the distance used to satisfy the airplane accelerate-stop distance performance requirements where the certification and operating rules require accelerate-stop distance computations
NOTE-The length of any available stopway will be included in the ASDA published in the Chart Supplement U.S.'s entry for that runway end
Landing Distance Available (LDA):
The runway length declared available and suitable for a landing airplane
The LDA may be less than the physical length of the runway or the length of the runway remaining beyond a displaced threshold if necessary to satisfy runway design standards; for example, where the airport operator uses a portion of the runway to achieve the runway safety area requirement
Although some runway elements (such as stopway length and clearway length) may be available information, pilots must use the declared distances determined by the airport operator and not attempt to independently calculate declared distances by adding those elements to the reported physical length of the runway
The airplane operating rules and/or the airplane operating limitations establish minimum distance requirements for takeoff and landing and are based on performance data supplied in the Airplane Flight Manual or Pilot's Operating Handbook
The minimum distances required for takeoff and landing obtained either in planning prior to takeoff or in performance assessments conducted at the time of landing must fall within the applicable declared distances before the pilot can accept that runway for takeoff or landing
Runway design standards may impose restrictions on the amount of runway available for use in takeoff and landing that are not apparent from the reported physical length of the runway or from runway markings and lighting
The runway elements of Runway Safety Area (RSA), Runway Object Free Area (ROFA), and Runway Protection Zone (RPZ) may reduce a runway's declared distances to less than the physical length of the runway at geographically constrained airports
When considering the amount of runway available for use in takeoff or landing performance calculations, the declared distances published for a runway must always be used in lieu of the runway's physical length
While some runway elements associated with declared distances may be identifiable through runway markings or lighting (for example, a displaced threshold or a stopway), the individual declared distance limits are not marked or otherwise identified on the runway
An aircraft is not prohibited from operating beyond a declared distance limit during the takeoff, landing, or taxi operation provided the runway surface is appropriately marked as usable runway
EXAMPLE:
The declared LDA for runway 9 must be used when showing compliance with the landing distance requirements of the applicable airplane operating rules and/or airplane operating limitations or when making a before landing performance assessment. The LDA is less than the physical runway length, not only because of the displaced threshold, but also because of the subtractions necessary to meet the RSA beyond the far end of the runway. However, during the actual landing operation, it is permissible for the airplane to roll beyond the unmarked end of the LDA
The declared ASDA for runway 9 must be used when showing compliance with the accelerate-stop distance requirements of the applicable airplane operating rules and/or airplane operating limitations. The ASDA is less than the physical length of the runway due to subtractions necessary to achieve the full RSA requirement. However, in the event of an aborted takeoff, it is permissible for the airplane to roll beyond the unmarked end of the ASDA as it is brought to a full-stop on the remaining usable runway
Declared Distances Constraints
Conclusion:
It is important for you to know the meanings of the signs, markings, and lights that are used on airports as surface navigational aids
Ineffective, incorrect, or confusing markings should be reported in at least one of three ways:
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 (ILS) critical areas, and taxiway/taxiway intersection markings
Familiarize pilots with Chart Supplements, Airport Diagrams, NOTAMs, and other preflight resources
Use the FAA's From the Flight Deck videos! www.faa.gov/airports/runway_safety/videos/
Share techniques to verify correct runway alignment, like magnetic compass orientation, referencing underlying instrument approach courses, mnemonic devices, etc.
Discourage over-reliance on technology-Electronic Flight Bags and moving map displays are intended to increase pilot situational awareness and safety-Take appropriate action when technology is compensating for skill or is a distraction
Encourage runway safety checks on short final, including verification of the correct runway, and ensuring that no vehicles or aircraft are present
Strictly enforce a go-around policy when there is any doubt of making a safe landing on the correct surface
For more information or resources, check out SAFO 17010
