Comprehensive Guide to Airport Markings, Signs, and Lighting Systems for Air Traffic Control

Fundamental Definitions of Airport Areas

• Airport: An airport is defined as an area on land or water that is used or intended to be used for the landing and takeoff of aircraft. This definition includes any associated buildings and facilities.
• Heliport: A heliport is an area on land or water that is used or intended to be used for the landing and takeoff of helicopters. This includes all its buildings and facilities.
• Helipad: A helipad is a small, designated area, usually featuring a prepared surface, located on a heliport, airport, landing/takeoff area, apron/ramp, or movement area. It is specifically used for the takeoff, landing, or parking of helicopters.

Movement and Non-Movement Areas

• Movement Areas: These areas consist of the runways, taxiways, and other portions of an airport or heliport utilized for the taxiing, hover taxiing, air taxiing, takeoff, and landing of aircraft. They specifically exclude loading ramps and parking areas.
  • At airports or heliports with an air traffic control tower, specific approval from Air Traffic Control (ATC) must be obtained before entering a movement area.
• Non-Movement Areas: These include the taxiways and apron (ramp) areas that are not under the control of air traffic.
  • Responsibility for the movement of aircraft or vehicles within non-movement areas lies solely with the pilot, the aircraft operator, or the airport management.

Pavement Markings and Color Systems

• Pavement markings are applied to runway and taxiway surfaces to identify specific runways, runway thresholds, centerlines, and hold lines.
• The color of the pavement marking identifies the specific airport area:
  • White: Used for runways and landing areas, including heliport landing symbols.
  • Yellow: Used for taxiways, closed areas, hazardous areas, and holding positions.

Runway Designators and Identification

• Designator Composition: Runways are identified by a number or a number followed by a letter. These are determined by the direction (magnetic heading) of the approach.
• Dual Designators: Each runway has two designators, one at each end.
• Magnetic Heading Calculation: The designator is determined by the runway centerline’s magnetic direction, expressed in $3$ digits and rounded to the nearest $10$ degrees.
  • Values ending in $4$ and lower are rounded down.
  • Values ending in $6$ and higher are rounded up.
  • Values ending in $5$ can be rounded either up or down.
• Two-Digit Identification: Only the first two numbers of the magnetic direction are used for the actual designator.
  • If the first number of the result is zero, the zero is deleted. For example, a heading of $094^\text{o}$ is rounded to $090^\text{o}$, and the designator becomes Runway $9$.
  • Magnetic headings of $360^\text{o}$ and $000^\text{o}$ are technically the same; however, in Air Traffic Control, $000^\text{o}$ is never used. Therefore, North-aligned runways use $36$.
• Parallel Runways: If an airport has parallel runways, a supplemental letter is added according to the order from left to right as seen from the approach:
  • Two parallel runways: $L$ (Left), $R$ (Right).
  • Three parallel runways: $L$ (Left), $C$ (Center), $R$ (Right).
  • Four or more runways: If an airport has more than three parallel runways, they will not all share the same number, even if they share the same magnetic heading. For example, four parallel runways would be designated as a pair of $L/R$ and another pair of $L/R$ using the adjacent heading number.

Primary Runway Surface Markings

• Runway Centerline Markings: These identify the physical center of the runway and provide alignment guidance for takeoff and landing. They consist of a line of uniformly spaced white stripes and gaps.
• Runway Threshold Markings: These identify the actual beginning point of the runway threshold used for landings. They consist of a pattern of longitudinal white stripes of uniform dimension ($150\,\text{feet}$ in length) spaced symmetrically about the centerline. The number of stripes indicates the runway width:
  • $4$ stripes: $60\,\text{feet}$
  • $6$ stripes: $75\,\text{feet}$
  • $8$ stripes: $100\,\text{feet}$
  • $12$ stripes: $150\,\text{feet}$
  • $16$ stripes: $200\,\text{feet}$
• Runway Aiming Point Markings: These provide a visual aiming point for landing operations. They are white and start approximately $1,000\,\text{feet}$ from the landing threshold.
• Runway Touchdown Zone Markings: These identify the touchdown zone along a precision runway in $500\text{-foot}$ increments. They consist of symmetrically arranged pairs of white rectangular bars in groups of one, two, and three. The aiming point is included within the touchdown zone markings.
• Runway Side Stripe Markings: These delineate the edges of the runway, providing contrast with the surrounding terrain or shoulders. They consist of continuous white stripes extending the full length of the runway.
• Runway Shoulder Markings: These are used as needed to delineate paved shoulders that might be mistaken for usable runway. These markings are yellow and consist of stripes starting at the runway midpoint, slanted at a $45^\text{o}$ angle to the centerline.

Area-Specific Markings and Safety Areas

• Displaced Threshold: This is a threshold located at a point other than the designated beginning of the runway. It reduces the length of the runway available for landings.
  • Non-landing portion: The area between the beginning of the runway pavement and the displaced threshold. It is available for takeoffs in either direction and for landing rollouts from the opposite direction.
  • Markings: A $10\text{-foot}$ wide white threshold bar is positioned perpendicular to the centerline at the point of displacement. Four white arrowheads pointing toward the landing portion are located adjacent to the bar. White arrows are also located along the centerline in the non-landing portion. Yellow taxiway centerline markings may sometimes extend into this area.
• Demarcation Bar: A yellow bar that delineates a runway with a displaced threshold from a blast pad, stop-way, or an aligned taxiway preceding the runway.
• Chevrons: Large yellow chevron markings identify paved blast pads, stop-ways, and Engineered Materials Arresting Systems (EMASs) in relation to the runway end. They point in the direction of the threshold.
• Blast Pad: A surface adjacent to runway ends designed to reduce the erosive effects of jet blast and propeller wash.
• Stop-way: An area beyond the takeoff runway capable of supporting an airplane during an aborted takeoff.
• EMAS: Constructed of high energy-absorbing materials, these are located in the safety area beyond the runway end to stop an aircraft.

Closed Runways and Taxiways

• A closed runway or taxiway is unusable and potentially hazardous, even if it looks usable.
• Permanently Closed:
  • Lighting circuits are disconnected.
  • Yellow crosses ($X$) are painted at each end of the runway and at $1,000\text{-foot}$ intervals.
  • Threshold, designation, and touchdown zone markings are obliterated.
• Temporarily Closed:
  • Operators may use a raised-lighted yellow "X" on each end or place a yellow "X" over the runway designation markings.
  • Temporarily closed taxiways are treated as hazardous areas where no aircraft may enter; they are marked with a yellow "X" or physically blocked with barricades.

Taxiway Markings and Boundaries

• Taxiway Centerline Marking: A continuous yellow line providing guidance for taxiing. All taxiways have this marking regardless of width.
• Taxiway Edge Markings: Used to delineate usable pavement from unusable areas.
  • Continuous Edge Markings: Used to separate the taxiway from a shoulder or other non-usable area.
  • Dashed Edge Markings: Indicate an area where pilots are permitted to cross the surface marking.
• Non-Movement Area Boundary Marking: Delineates the movement area from the non-movement area.
  • It consists of one dashed yellow line and one solid yellow line.
  • The solid line is always on the side of the non-movement area.
• Taxiway Shoulder Markings: Optional yellow markings indicating that the pavement is not intended for aircraft use and may not support aircraft weight.

Airport Signs and Guidance Systems

• Mandatory Instruction Signs: Feature a red background with white inscriptions. They denote runway entrances, critical areas, or prohibited entry zones without ATC clearance.
  • Surface Painted Holding Position Sign: A red background with white text, such as "$9-27$", indicating the aircraft must hold short of that runway intersection.
  • No Entry Sign: Typically located on taxiways intended for one-way traffic.
• Location Signs: Feature a black background with yellow inscriptions and a yellow border.
  • Runway Location Signs: Identify the runway the aircraft is currently on.
  • Taxiway Location Signs: Identify the current taxiway.
• Direction Signs: Feature a yellow background with black inscriptions and always include an arrow indicating the direction to turn to reach a specific taxiway.
• Runway Distance Remaining Signs: Feature a black background with white inscriptions. The number indicates the distance remaining in thousands of feet. For example, a sign with "$3$" means $3,000\,\text{feet}$ of landing runway remain.
• Runway Holding Position Markings: Consist of four yellow lines (two solid and two dashed) extending across the width of the taxiway or runway. The solid lines are on the side where the aircraft is required to hold.
• Surface Painted Taxiway Signs: These supplement or replace physical signs when impractical. Location signs are usually on the right side of the centerline; direction signs are on the side of the turn (left for left, right for right).

helicopter Landing Area Symbols

• The orientation of the letter "H" in landing area markings is aligned with the intended direction of approach.
• Civil Heliport: Features a white "H".
• Hospital Heliport: Features a red "H" inside a large red-outlined cross.
• Closed Heliport: Features a yellow "X" through the "H".

Airport Beacons

• Rotating beacons identify the type of airport and are typically turned on at night or during restricted weather (visibility < $3\,\text{statute miles}$ or ceiling < $1,000\,\text{feet}$).
• Lighted Land Airport: Flashing white and green.
• Lighted Water Airport: Flashing white and yellow.
• Lighted Heliport: Flashing white, yellow, and green.
• Military Airport: Two quick white flashes followed by a green flash.

Comprehensive Runway Lighting Systems

• Runway End Identifier Lights (REILs): A pair of synchronized white flashing strobe lights located laterally on each side of the runway threshold, facing incoming traffic.
• Runway Edge Light System: Outlines the edges of runways and is classified by intensity.
  • Lights are generally white except on instrument runways, where yellow replaces white on the last $2,000\,\text{feet}$ or half of the runway length, whichever is less.
• Runway End/Threshold Lights:
  • Emit red light toward the runway to indicate the runway end.
  • Emit green light outward from the runway to indicate the landing threshold (known as "Threshold Lights").
• In-Runway Lighting:
  • Touchdown Zone Lighting (TDZL): Two rows of lights on each side of the centerline. Starts $100\,\text{feet}$ from the threshold and extends to $3,000\,\text{feet}$ or the runway midpoint.
  • Runway Centerline Lighting System (RCLS): Spaced at $50\text{-foot}$ intervals. They are white until the last $3,000\,\text{feet}$; then alternating white and red for the next $2,000\,\text{feet}$; and all red for the final $1,000\,\text{feet}$.

Visual Descent and Approach Lighting

• Visual Glideslope Indicators: Systems like the Visual Approach Slope Indicator (VASI) or Precision Approach Path Indicator (PAPI) provide descent guidance. Visible from $3-5\,\text{miles}$ during the day and $20\,\text{miles}$ or more at night.
• Approach Light Systems (ALS): Help transition from instrument to visual flight. They extend into the approach area from the landing threshold:
  • $2,400-3,000\,\text{feet}$ for precision instrument runways.
  • $1,400-1,500\,\text{feet}$ for non-precision instrument runways.
  • Sequenced Flashing Lights (SFLs): May be included, appearing as a ball of light traveling toward the runway twice per second.

Taxiway and Runway status Lighting

• Taxiway Edge Lights: Emit a blue light to outline taxiway edges.
• Taxiway Centerline Lights: Emit a steady green light for use in low visibility.
• Runway Guard Lights: Installed at holding positions to attract attention in low visibility. Consist of in-pavement yellow light rows or elevated flashing yellow lights.
• Stop Bar Lights: Red, unidirectional, in-pavement lights across the entire taxiway at the runway holding position, plus elevated steady red lights on the sides. They confirm ATC clearance to enter the runway.
• Lead-on Lights: Row of alternating yellow and green unidirectional in-pavement lights extending from the stop bar to the runway.
• Runway Status Lights (RWSL): Automated systems that turn red to warn pilots when it is unsafe to enter, cross, or take off.
  • Runway Entrance Lights (RELs): Indicate traffic is on the runway and it is unsafe to enter. Pilots must stay at the hold line.
  • Takeoff Hold Lights (THLs): Lit red when an aircraft is in the takeoff hold area while another aircraft is on the runway. They extinguish when the runway is clear.

Questions & Discussion

Knowledge Check A

• Question 1: At an airport with a tower, when is movement permitted in a designated movement area?
  • Answer: Only after obtaining approval from ATC.
• Question 2: How would you designate a runway with a magnetic heading of $094$ degrees?
  • Answer: RWY $9$.
• Question 3: How would you designate a runway with a magnetic heading of $005$ degrees?
  • Answer: RWY $36$ or $1$.

Knowledge Check B

• Question 1: A runway with a non-precision approach does NOT have which of the following runway markings?
  • Answer: Touchdown zone.
• Question 2: Where are displaced threshold markings located on a runway?
  • Answer: At a point on the runway other than the designated beginning of the runway; at the end of the non-landing portion of the runway.
• Question 3: Which surface on a runway is marked with large yellow chevrons?
  • Answer: Blast pad.

Knowledge Check C

• Question 1: Which markings indicate that the pavement is NOT intended for use by aircraft?
  • Answer: Taxiway shoulder markings.
• Question 2: The centerline of a taxiway is marked with what type of line?
  • Answer: Continuous yellow.
• Question 3: What is indicated by a taxiway direction sign?
  • Answer: Which direction the aircraft must turn to get to the desired taxiway.
• Question 4: What does the orientation of the letter "H" indicate on a helicopter landing area?
  • Answer: Aligns with the intended direction of approach.

Knowledge Check D

• Question 1: Match the airport type with its beacon color:
  • Lighted land airport: Flashing white and green.
  • Lighted heliport: Flashing white, yellow, and green.
  • Military airport: Two quick white flashes and green.
  • Lighted water airport: Flashing white and yellow.
• Question 2: Which lights consist of two white flashing strobe lights located on each side of the runway threshold?
  • Answer: Runway end identifier lights.
• Question 3: Which lights mark the beginning of the runway for an approaching aircraft?
  • Answer: Threshold lights.
• Question 4: Which type of lighting consists of two rows of lights on each side of runway centerline lights?
  • Answer: Touchdown zone lighting.

Knowledge Check E

• Question 1: Which light system provides visual descent guidance during runway approaches?
  • Answer: Visual glideslope indicators.
• Question 2: Which lights are used to confirm ATC clearance to enter the active runway?
  • Answer: Stop bar lights.
• Question 3: Match the taxiway light with its designated color:
  • Runway guard lights: Yellow.
  • Stop bar lights: Red.
  • Lead-on lights: Yellow and green.
  • Taxiway edge lights: Blue.
  • Taxiway centerline lights: Green.
• Question 4: Which type of lights tell pilots and vehicle operators to stop when runways are not safe?
  • Answer: Runway status lights.