The Essential Guide to Runway Signs

Quickly reading and understanding airport signs is critical to becoming a safe pilot.

Missing a freeway exit sign on the road isn’t a big deal. At an airport, overlooking a sign could delay traffic at best and be dangerous at worst.

Luckily, we’re here to help.

In this article, you’ll learn what airport signs mean, how to read them, and where you’ll find them.

After reading this guide, complete your knowledge with our Essential Guide to Runway Markings.

Key Takeaways

• Airports use six main types of signs, each with a specific color and purpose.
• Mandatory instruction signs mark areas you can’t enter without clearance.
• Location, direction, and destination signs guide ground movement.
• Runway distance remaining signs show how much runway is left in 1,000-ft intervals.

Types of Airport Signs

The FAA classifies airport signs into six main types:

1. Mandatory Instruction Signs: indicate areas where entry is prohibited without clearance, such as runways or critical areas.
2. Location Signs: identify the current position on a taxiway or runway.
3. Direction Signs: point toward other taxiways or runways from an intersection.
4. Destination Signs: indicate the direction to destinations like terminals or FBOs.
5. Information Signs: provide helpful data, like radio frequencies or noise abatement procedures.
6. Runway Distance Remaining Signs: show the length of runway left in 1,000-foot increments.

Let’s take a look at each in detail.

1. Mandatory Instruction Signs

Mandatory instruction signs mark critical areas (such as runways) where aircraft are not allowed to enter without clearance. They also mark areas where aircraft are not allowed to enter at all.

Mandatory instruction signs have the following characteristics:

• Color: They feature white text on a red background.
• Shape: These signs are usually rectangular or square, with the text and symbols properly centered.
• Location: You can find them at taxiway and runway intersections, holding positions, and other critical points on the airport surface.

There are four types of mandatory instruction signs:

• Runway Holding Position Signs
• Runway Approach Area Holding Position Signs
• ILS Critical Area Holding Position Signs
• No Entry Signs

Runway Holding Position Signs

A Runway Holding Position sign indicates where to stop and hold before entering or crossing a runway.

You’ll find runway-holding position signs where taxiways intersect with runways.

Accompanying them are painted markings on the taxiway surface, consisting of two solid yellow lines followed by two dashed yellow lines.

Runway holding position signs display the runway designation, such as “27” or “9,” indicating the runway you’re about to enter or cross. The inscription might include a letter (e.g., “L” or “R”) to identify parallel runways (e.g., “27L” or “27R”).

Runway Approach Area Holding Position Signs

A Runway Approach Area Holding Position sign indicates where pilots must stop and hold before entering an area that could interfere with aircraft on the final approach.

You’ll find the runway approach area holding position signs on taxiways near approach areas where aircraft are descending for landing. 

These signs indicate that you are approaching a point where your aircraft may interfere with the safety of the aircraft on the final approach, even if you are not directly entering or crossing the runway.

The sign displays the runway designation for the approach end followed by a dash and “APCH” (e.g., “27 – APCH”). If it also protects a departure area, it will include the departure end runway designation and “DEP” (e.g., “15 APCH – 33 DEP”).

ILS Critical Area Holding Position Sign

An ILS (Instrument Landing System) Critical Area Holding Position sign denotes the ILS critical area. The ILS critical area helps maintain the accuracy and reliability of ILS signals during instrument approaches in low visibility conditions by limiting how close aircraft on the ground get to the ILS equipment (and signals).

You’ll find ILS Critical Area Holding Position signs on taxiways near the critical areas of ILS, typically close to the runway threshold or glide slope transmitter.

The sign displays the letters “ILS” indicating you’re approaching the ILS critical area.
You should be aware of ILS critical areas and follow ATC instructions regarding holding short. Entering an ILS critical area without clearance can affect ILS signal integrity. (Retain the safety message but remove unverified terminology).

Remember that entering the ILS critical area without proper clearance may cause signal interference, potentially affecting the safety of aircraft conducting instrument approaches. 

Stay aware of ILS critical area holding position signs and their purpose.

No Entry Sign

You’ll find No Entry signs at the entrance of restricted areas, such as one-way taxiways, closed taxiways, or other areas where aircraft are not allowed to enter.

Ignoring a no-entry sign can lead to unsafe situations or violations of airport regulations, which may result in penalties or suspension of your pilot’s license. Do not enter areas beyond a no-entry sign unless you have specific permission.

2. Location Signs

Airport Location Signs are essential for helping pilots navigate the complex network of taxiways, ramps, and other areas while on the ground. These airport location signs help you to identify your current position through a network of taxiways and runways. 

Specific types of location signs, like the Runway Boundary Signs and ILS Critical Area Boundary Signs, also indicate the edges of defined operational areas.

Location signs have the following characteristics:

• Colors: Taxiway Location Signs and Runway Location Signs have yellow inscriptions on a black background with a yellow border. Runway Boundary Signs and ILS Critical Area Boundary Signs have black inscriptions on a yellow background.
• Location: You’ll find location signs along taxiways, ramps, and aprons. They are often placed next to directions or mandatory instruction signs to help pilots identify their position on the airport surface.
• Content: The sign displays an alphanumeric code, such as “A,” “B,” or “1,” which corresponds to the designation of the taxiway or area you’re on. The sign displays a letter or a combination of letters and numbers (e.g., “A” or “B1”), which corresponds to the designation of the taxiway you’re on.

There are four types of location signs:

• Taxiway Location Signs
• Runway Location Signs
• Runway Boundary Signs
• ILS Critical Area Boundary Signs

Taxiway Location Signs

Taxiway Location Signs are used to identify the current taxiway that the aircraft is on.

You’ll find taxiway location signs along taxiways, often near intersections or at points where taxiways meet ramps or aprons. You’ll sometimes find them next to directions or mandatory instruction signs to provide context for your current location.

The sign displays a letter or a combination of letters and numbers (e.g., “A” or “B1”), which corresponds to the designation of the taxiway you’re on. The sign displays a letter or a combination of letters and numbers (e.g., “A” or “B1”), which corresponds to the designation of the taxiway you’re on.

Runway Location Sign

You’ll find Runway Location signs near runway holding positions or intersections where taxiways meet runways. They are often placed with mandatory instruction signs, such as Runway Holding Position Signs, to provide context for your current location.

A runway location sign displays the designation of the runway on which the aircraft is located (e.g., “15” or “36L”), which corresponds to the runway you are currently on.

The runway numbers represent the magnetic heading of the runway rounded to the nearest 10 degrees, while the letters “L” and “R” indicate left or right for parallel runways.

Runway Boundary Sign

A Runway Boundary Sign has a yellow background with a black inscription and a graphic depicting the runway holding position marking.

This sign faces the runway and is visible to the pilot exiting the runway. It is located adjacent to the holding position marking on the pavement. 

The sign is intended to provide pilots with another visual cue they can use as a guide in deciding when they are “clear of the runway.”

Runway holding position signs denote the intersection between the taxiway and the runway where aircraft must stop if they do not have clearance to enter the runway. It is effectively where the runway begins, and the taxiway ends.

ILS Critical Area Boundary Sign

An ILS Critical Area Boundary Sign has a yellow background with a black inscription and a graphic depicting the ILS pavement holding position marking.

This sign is found adjacent to the ILS holding position marking on the pavement and can be seen by pilots leaving the critical area. 

Basically, this sign is intended to provide you with another visual cue that you can use as a guide in deciding when you are “clear of the ILS critical area.”

ILS critical area markings on the taxiway.

3. Direction Signs

Direction Signs have the following characteristics:

• Colors: Direction signs have black inscriptions on a yellow background.
• Location: You’ll find direction signs along taxiways, ramps, and aprons, typically at intersections or junctions where pilots may need guidance to follow the correct path.
• Content: The sign displays an alphanumeric code, such as “A,” “B,” or “1,” which corresponds to the designation of the taxiway, runway, or area, followed by an arrow pointing in the direction of the turn. This code corresponds to the designation of the taxiway, runway, or area, in the direction of the arrow. Multiple arrows and designations may sometimes be displayed on the same sign.

4. Destination Signs

Destination Signs are similar to direction signs and share the same colors and shapes.

There is one critical difference, though.

Destination signs mark the direction that an aircraft needs to go to arrive at the destination depicted on the sign (such as the FBO in the example). Directional signs mark the direction of a particular runway or taxiway at an intersection.

5. Information Signs

Information Signs feature black inscriptions on a yellow background. These inscriptions are usually pieces of text containing important information.

These signs can be found anywhere at the airport.

6. Runway Distance Remaining Signs

Runway Distance Remaining signs are essential for providing pilots with information about the remaining usable distance of a runway for takeoff or landing. These signs help pilots assess if they have enough runway available to complete their takeoff or landing safely.

Here’s an overview of runway distance remaining signs:

• Colors: Runway distance remaining signs have white inscriptions on a black background.
• Content: The sign displays a number, usually representing the remaining distance in thousands of feet (e.g., “5” for 5,000 feet).
• Location: You’ll find these signs alongside runways, typically installed at regular intervals, such as every 1,000 feet.

Conclusion

Airport signs play a critical role in maintaining the safety and efficiency of airport operations. As a pilot, understanding and quickly interpreting these signs is essential.

Always stay vigilant and use all available resources, including airport diagrams and ATC instructions.

Don’t forget to check out our Essential Guide to Airport Markings to further enhance your knowledge and skills in navigating the airport.

Safe flying!