Runway Incursions

Reference: AC 91-73

A runway incursion is any occurrence at an aerodrome involving the incorrect presence of an aircraft, vehicle, or person on the protected area of a surface designated for the landing and takeoff of aircraft.

A surface incident is similar to a runway incursion but occurs on a designated movement area (not a runway) and affects or could affect the safety of flight.

Taxi Instructions

References: AIM 4-3-18, AIM 5-2-5, AC 91-73

When transmitting taxi instructions, ATC specifies:

1. The departure runway.
2. The taxi route.
3. Any hold short instructions or runway crossing clearances if the taxi route crosses a runway.

Note: To prevent misunderstandings, ATC never uses the word “cleared” in conjunction with taxi instructions.

Movement Versus Nonmovement Areas

A movement area is the runways, taxiways, and other areas of an airport that are used for taxiing, takeoff, and landing. Nonmovement areas include ramps and parking areas and are not controlled by ATC.

At a towered airport, the movement area is controlled by ATC. Pilots must receive clearance before taxiing in a movement area.

Required Readbacks

Pilots must always read back:

• The runway assignment.
• Any clearance to taxi onto or cross a specific runway.
• Any instruction to hold short of a runway or line up and wait.

The readback for a hold short instruction should include the words “hold short,” the runway or taxiway designator, and the aircraft’s call sign.

Progressive Taxi

If the pilot is unfamiliar with the airport or unsure of a taxi route, a “progressive taxi” should be requested. Progressive taxi requires ATC to provide step-by-step taxi instructions.

Hold Short Instructions

When ATC issues “hold short” instructions, the pilot is expected to taxi up to but not cross any part of the runway holding marking.

Example Instructions: "Runway 36L, taxi via Alpha, hold short of Runway 27."

ATC issues further instructions if pilots are expected to hold short of a runway approach/departure hold area (e.g., 22-APPCH/22-DEP) or ILS holding position.

Explicit Runway Crossings

ATC must issue specific instructions to “cross” or “hold short” of each runway, even if the runway is closed. Instructions to cross a runway are typically issued one at a time, and an aircraft must have crossed the previous runway before another runway crossing is issued. Exceptions are made for closely spaced runways.

Pilots may not enter a runway unless they have been:

• Instructed to cross or taxi onto that runway;
• Cleared to take off from that runway; or
• Instructed to line up and wait on that runway.

Line Up and Wait

ATC uses the “line up and wait” (LUAW) instruction when a takeoff clearance cannot be issued immediately. ATC should state the reason for any delay in issuing the takeoff clearance.

Example Instructions: "Runway 27, line up and wait."

The pilot should contact ATC if a takeoff clearance is not received within 90 seconds of getting a line-up-and-wait instruction.

Example: "[call sign] holding in position Runway 27."

Best Practices for Line-Up-and-Wait Operations

• Turn on the traffic information displays, if equipped, to increase awareness of landing traffic.
• Make the aircraft more conspicuous to aircraft on final and ATC by turning on all lights except for landing lights that highlight the aircraft’s silhouette.
• At night, consider lining up slightly (approximately 3′) to the left or right of the centerline to enable a landing aircraft to visually differentiate your aircraft from the runway lights.
• Do not wait on the runway at nontowered airports.

Use of Written Taxi Instructions

When the taxi instructions are complex, written instructions are desirable. Written instructions can be used to read back the instructions to ATC and recall any forgotten information later. To help copy the instructions, pilots should develop a set of symbols and shorthand notations.

Suggested shorthand symbols:

• Hold Short: A slash (/) before the hold point
• Cross: (×) before the runway number
• Turn: Left (←) or Right (→)

Example Instructions: "Runway 36L, taxi via Bravo, Echo, hold short of Runway 27 at Echo."
Example Shorthand: "36L B E /27 E"

Holding Position Markings

References: AIM 2-3-5, AC 150/5340-1

Runway holding position markings indicate where an aircraft is supposed to stop when approaching a runway. These markings consist of four yellow lines, two solid and two dashed, extending across the taxiway or runway width. The solid lines are always on the side where the aircraft is to hold.

Runway holding position markings may be encountered:

• On taxiways where an aircraft is supposed to stop when it does not have clearance to proceed onto the runway.
• On runways that ATC uses for land and hold short operations (LAHSO) or taxiing operations.
• On taxiways located in runway approach areas are used at some airports where a taxiway is located in an approach or departure area. ATC notifies pilots when to hold short of a runway approach or departure area (e.g., “22-APCH” sign).

Example Instructions: "Hold short of Runway 32 approach area."

Holding position markings for instrument landing system (ILS) critical areas consist of two solid yellow lines (horizontal) connected by pairs of solid lines (vertical) extending across the width of the taxiway. ATC notifies pilots when to hold short of an ILS critical area.

Holding position markings for taxiway/taxiway intersections consist of a single, yellow dashed line extending across the taxiway’s width.

Taxiway Markings

References: AIM 2-3-4, AC 150/5340-1

Enhanced taxiway centerline markings are used at larger airports to warn pilots that they are approaching a runway holding position marking. These markings consist of two parallel, yellow-dashed lines located on either side of the normal taxiway centerline beginning approximately 150′ before a runway holding position marking.

Normal taxiway centerline markings are a single continuous yellow line. Ideally, the aircraft should be kept centered over this line during taxi. However, being centered on the taxiway centerline does not guarantee wingtip clearance with other aircraft or objects.

Surface-painted location signs are located on the right side of the centerline to assist the pilot in confirming the taxiway on which the aircraft is located. These markings have a black background with a yellow inscription.

Geographic position markings are located at points along low-visibility taxi routes to identify a taxiing aircraft’s location during low-visibility operations. These markings consist of an outer white or black ring with a pink circle in the middle. Either a number or a number and letter are positioned in the center of the pink circle.

Surface-painted taxiway direction signs are provided when it is not possible to provide taxiway direction signs at intersections or when necessary to supplement such signs. These markings have a yellow background with a black inscription.

Edge markings help define the taxiway’s edge, primarily when the taxiway edge does not correspond with the edge of the pavement. These markings typically consist of continuous double yellow lines. Dashed lines are used when the adjoining pavement is intended to be used by aircraft (e.g., ramps and run-up areas).

Shoulder markings are yellow stripes that are used where conditions exist, such as taxiway curves that may cause confusion as to which side of the edge stripe is for use by aircraft. A taxiway shoulder is not intended for use by aircraft.

Taxiway Lighting

References: AIM 2-1-10, AC 150/5340-30

Taxiway edge lights outline the edges of taxiways during periods of darkness or restricted visibility conditions. They are steadily burning and emit blue light.

Taxiway centerline lights are located along the taxiway centerline to facilitate ground traffic under low visibility conditions. They are steadily burning and emit green light.

Clearance bar lights consist of three yellow in-pavement lights. They are installed at some taxiway holding positions to increase the conspicuity of the holding position in low visibility conditions and periods of darkness.

Runway guard lights are installed at taxiways that provide access to an active runway and may be used in all weather conditions. They consist of elevated or in-pavement, alternately flashing yellow lights that identify the location of a runway holding position marking.

Elevated runway guard lights are called “wig-wag” lights because they blink on and off in an alternating fashion.

Stop bar lights confirm the ATC clearance to enter or cross the active runway in low visibility conditions. They consist of a row of red, unidirectional, elevated, and in-pavement lights placed at the runway holding position (runway entrance or ILS critical area). These lights may be operated automatically or controlled by ATC. Following an ATC clearance to proceed, the stop bar is turned off, and the taxiway centerline lead-on lights are turned on.

Caution: Never cross a red illuminated stop bar, even if an ATC clearance has been received.

Airport Signs

References: AIM 2-3-7, AC 150/5340-18

Mandatory instruction signs have a red background with a white inscription. They are used to denote an entrance to a runway or critical area, and areas where an aircraft is prohibited from entering.

Typical mandatory signs and applications are:

• Runway holding position signs
• Runway approach area holding position signs
• ILS critical area holding position signs
• No entry signs

Location signs typically have a black background with a yellow inscription and yellow border. They are used to identify where the aircraft is located.

Typical location sign applications are:

• Taxiway location signs
• Runway location signs
• Runway boundary signs (yellow background with a black graphic depicting the runway holding position marking)
• ILS critical area boundary signs (yellow background with a black graphic depicting the ILS holding position marking)

Direction signs have a yellow background with a black inscription. Each designation is accompanied by an arrow indicating the direction of the turn.

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 to a destination. Destinations commonly shown are runways, terminals, cargo areas, and FBOs.

Information signs have a yellow background with a black inscription. These signs provide the pilot with information such as radio frequencies and noise abatement procedures.

Runway distance remaining signs have a black background with a white numeral inscription and may be installed along one or both sides of the runway. The number on the signs indicates the distance, in thousands of feet, of runway remaining.

Hot Spots

References: Aeronautical Chart User’s Guide, Chart Supplements

A hot spot is a location in an airport movement area with a history or potential risk of collision or runway incursion, where pilots’ and drivers’ heightened attention is necessary. They are typically located at confusing taxiway and runway intersections.

Chart Depiction of Hot Spots

Hot spots are depicted on airport diagrams as an open circle or ellipse for ground movement hot spots and a cylinder (rectangle) for wrong surface hot spots. They are designated by “HS” and a number (e.g., HS 1 or HS 2).

Hot spots are also described in Chart Supplements publications under the “Hots Spots” heading. They remain charted until the increased risk has been reduced or eliminated.

Hazards Unique to Taxiing

The airport environment has unique hazards that must be managed, including:

• Movement in confined areas.
• People or vehicles on the ramp.
• High workloads (e.g., stress and “heads-down” time).
• NOTAMs for closed taxiways and construction areas.
• Controlled ramps and taxiways (e.g., complexity, responsibilities, and missed clearances).
• Uncontrolled ramps and taxiways (e.g., no-radio aircraft, obstructions, unimproved surfaces).
• Aircraft moving nearby (e.g., collisions, runway incursions, and propeller/jet blast).
• Tie-down ropes and loose debris that can be picked up by a propeller.
• Aircraft design characteristics (e.g., tailwheel, castering nosewheel, wing length).
• Hot spots (areas designed to alert pilots to potential conflicts).
• Crosswinds or tailwinds that can cause a wing to rise.
• Taxiing on a snow-covered or icy taxiway.
• Low visibility operations (LVO). [IFR]

Towered Airport Considerations for Taxiing

• Know the location of hot spots.
• Clear both left and right before crossing a runway.
• Never assume a runway is clear just because clearance is received to taxi onto it.
• When cleared to take off or cross a runway, or when exiting a runway, do so promptly.
• Never stop on a runway unless instructed by ATC to do so.
• Be cautious of expectation bias when copying clearances (hearing what is expected instead of what is said).
• Be aware that hold short lines may be located as far as 400′ from the runway edge.
• Exercise increased awareness when taxing in between active parallel runways.

Nontowered Airport Considerations for Taxiing

References: AC 90-66, AC 91-73

• Continuously monitor and communicate on the appropriate frequency. Remember that some aircraft may not be equipped with a radio.
• Scan the full length of the runway, including the final approach paths, before entering or crossing a runway.
• Remember that there is no “active” runway. Flight operations may occur on more than one runway.
• Aircraft may be flying an instrument approach to runways other than the runway in use for takeoff and landing.

Airport Knowledge and Planning

Reference: AC 91-73

Pilots should give as much attention to planning the airport surface movement as other phases of flight. This planning should be completed in two phases: review items and briefing items.

Review Items

• Current airport NOTAMs.
• If available, the ATIS for runway and taxiway closures, construction activity, and other airport-specific risks.
• The current airport diagram.
• Standard taxi routes, if published.
• The location of hot spots and other potential areas for a runway incursion.
• The suitability of intersections that may be used at takeoff.

Briefing Items

• The expected taxi route, to include the locations of hold short lines and runways to cross.
• Critical locations on the taxi route (e.g., hot spots, complex intersections, and crossing runways).
• The display of the airport diagram and the plan to track progress on the chart.
• The timing and execution of aircraft checklists and communications at times that will not interfere with taxiing activity.
• The importance of maintaining a sterile cockpit, but encourage occupants to speak up if a potential conflict is spotted.
• Unusual procedures or techniques that are not typically used.
• Remind all cockpit occupants the use of cell phones and other electrical devices is discouraged.

Procedures for Maintaining Orientation

Reference: AC 91-73

An essential requirement for conducting safe taxi operations is maintaining situational awareness. Pilots should always know where people, equipment, and other aircraft are.

Pilots should use a “continuous loop” process to monitor and update their progress and location during taxi. All visual cues, including airport signs, markings, and lighting, should be used together with the airport diagram to maintain the planned taxi route.

When uncertain about their location, pilots should ensure they are clear of a runway, stop the aircraft, and advise ATC. Progressive taxi instructions can be requested if necessary.

Best Practices for Maintaining Orientation

• Keep track of the aircraft’s progress on the airport diagram.
• Maintain a sterile cockpit and keep pilot workload to a minimum while the aircraft is moving.
• Have a working knowledge of airport markings and signs.
• Request progressive taxi instructions at unfamiliar airports.
• Use all available resources, including the heading indicator and airport signs, markings, and lighting.

Best Practices for Avoiding Surface Deviations

The best way to avoid a runway incursion is to make sure you understand (1) where you are at, (2) what you have been cleared to do, and (3) where you are going.

Standard Operating Procedures (SOPs): GA pilots should develop and adhere to SOPs based on regulations and industry best practices. A sterile cockpit and proper use of aircraft lights should be defined in every pilot’s set procedures.

Situational Awareness (SA): Pilots can establish SA by reviewing the expected taxi route and hot spot locations. Pilots can maintain SA by avoiding heads-down time when taxiing.

Proficiency: Recurrent training and continuing education lead to proficiency. A flight to a towered airport with an experienced instructor is a good way to learn and practice.

Point and Acknowledge: Pointing at and calling out location signs and markings can help a pilot maintain focus and attention.

Recommended Usage of Exterior Lighting

References: 14 CFR 91.209, AIM 4-3-23, AC 91-73, SAFO 11004

• Engines Running: Beacon ON
• Sunset to Sunrise: Position lights ON
• Taxi (While Moving): Taxi light ON
• Taxi (When Stopped or Yielding): Taxi light OFF
• Crossing a Runway: All exterior lights ON
• Line Up and Wait: Landing light OFF; All other exterior lights ON
• Takeoff and Landing: All exterior lights ON
• Climb and Descent: All exterior lights ON

Note: Pilots should consider the effects of illuminating strobe and forward-facing lights on the vision of other pilots or ground personnel. These lights should not be illuminated during taxi if they adversely affect safety.

Best Practices for Avoiding Runway Incursions During Takeoff

At All Airports:

• Scan the final approach path and runway environment before entering the runway.
• Verify the correct runway by observing the runway designation marking or sign.
• Verify the heading indicator matches the runway direction.

At Nontowered Airports:

• Do not “line up and wait.”
• Make a 360° turn to scan for traffic.
• Communicate and listen on the appropriate frequency.
• Be aware that traffic may use more than one runway, especially if the winds are light or variable.

At Towered Airports:

• Before entering the runway, ensure you are cleared to do so and that it is safe (“trust but verify”).

Exiting the Runway After Landing

References: AIM 4-3-20, AC 91-73

Unless otherwise instructed by ATC, pilots must:

• Exit the runway without delay at the first available taxiway or on a taxiway.
• Taxi beyond the runway holding position markings associated with the landing runway, even if that requires the aircraft to protrude into or cross another taxiway or ramp area.
• Hold until ATC issues further instructions.

Unless otherwise instructed by ATC, pilots cannot:

• Cross a subsequent taxiway or runway after clearing the runway.
• Exit the landing runway onto another runway.
• Stop or reverse course on the runway.

Best Practices for Avoiding Runway Incursions After Landing

References: AIM 4-3-20, AC 91-73

• Before landing, review and brief the expected taxi route using the airport diagram.
• During the approach briefing, establish a plan to avoid entering nearby runways when exiting the runway.
• Do not exit onto another runway without ATC authorization.
• Never stop on an active runway to ask for directions; clear the runway first.
• Guard against the pitfall of following expectations instead of the instructions received from ATC.

Night Considerations for Taxiing

• Taxi slowly, particularly in congested areas.
• Use extra caution when entering or crossing a runway.
• Avoid using the strobe lights and bright, forward-facing lights around other aircraft.
• When stopped, use extra vigilance to ensure the airplane does not creep forward.
• Adjust the interior lights to a minimum brightness that allows reading the instruments and switches. Dimming the lights reduces reflections on the windows.

Low Visibility Taxi Operations [IFR]

References: AIM 4-3-19, AC 91-73

Low visibility conditions increase the risk of a runway incursion. Pilots should be aware that their aircraft may not be visible to the tower controller. This may prevent visual confirmation of the aircraft’s adherence to taxi instructions.

Best Practices for Low Visibility Operations

• If published, review and brief the low visibility taxi chart, and be alert if ATC states to hold short of the ILS critical area.
• Perform all heads-down tasks while the aircraft is stopped.
• Checklists and nonessential communication should be withheld until the airplane is stopped and the brakes are set.
• Notify ATC when difficulties are encountered or at the first indication of becoming disoriented.

Risk Examples for Technical Subjects

Distractions, Task Prioritization, Loss of Situational Awareness, or Disorientation

• Distractions, task prioritization, loss of situational awareness, and disorientation increase the likelihood of errors, delayed or missed actions, and the inability to process information accurately and timely; minimize non-essential activities, follow the “Aviate, Navigate, Communicate” prioritization, and stay focused.

Confirmation or Expectation Bias as Related to Taxi Instructions

• Confirmation bias causes selectively hearing taxi instructions that align with previous beliefs, leading to incorrect taxi routes; question assumptions and verify instructions with ATC.
• Expectation bias results in acting on anticipated clearances based on past experience, missing changes in current instructions; stay vigilant for changes and review instructions carefully.

Entering or Crossing Runways

• Miscommunication with ATC increases the likelihood of entering or crossing a runway without clearance; verify instructions with ATC, repeat back clearances, and ask for clarification if uncertain.
• Not visually confirming the runway is clear can result in collisions with landing or departing aircraft; visually check for traffic before entering or crossing a runway, even if cleared by ATC.
• Distraction while taxiing increases the likelihood of runway incursions; avoid non-essential tasks and focus attention outside the aircraft.

Runway Incursions During Night Operations

• Difficulty in seeing taxiway markings and signs can lead to misidentifying taxiways or runways and increase the likelihood of runway incursions; maintain heightened situational awareness and reduce taxi speed.
• Improper use of exterior lights increases the risk of not being seen; check the operation of all exterior lighting during preflight inspection and use external lighting when appropriate.

Low Visibility Taxi Operations

• Poor visibility increases the likelihood of making a wrong turn or inadvertently entering a runway; use an airport diagram and taxi at reduced speeds.
• Difficulty in following taxi instructions due to reduced visibility can lead to disorientation; seek ATC assistance when necessary.

Runway Incursion After Landing

• Not clearing the runway quickly increases the likelihood of runway incursions; exit the runway promptly on the first available taxiway.
• Airports with close parallel runways increase the likelihood of runway incursions due to proximity; maintain situational awareness and follow ATC instructions closely.

Operating on Taxiways Between Parallel Runways

• Incorrect taxiway identification can lead to runway incursions or conflicts with aircraft on the taxiway; review airport diagrams.
• Miscommunication with ATC can result in runway incursions or conflicts with aircraft on the taxiway; maintain clear, concise communication with ATC.