AIM Text
There are six types of signs installed on airfields: mandatory instruction signs, location signs, direction signs, destination signs, information signs, and runway distance remaining signs. The characteristics and use of these signs are discussed in paragraph 2-3-8, Mandatory Instruction Signs, through paragraph 2-3-13, Runway Distance Remaining Signs.
FIG 2-3-24
Runway Holding Position Sign
FIG 2-3-25
Holding Position Sign at Beginning of Takeoff Runway
Source: FAA Aeronautical Information Manual · current edition · paragraph 2-3-7.
The short answer
AIM 2-3-7 is FAA advisory guidance listing the six types of airport signs — mandatory instruction, location, direction, destination, information, and runway distance remaining — and (with 2-3-8) details mandatory instruction signs: red background, white inscription, denoting runway entrances, critical areas, and no-entry areas. It supports compliance with taxi and runway-holding requirements under 14 CFR 91.129.
Research Notes
Common Questions
How many types of airport signs are there and what are they?
AIM 2-3-7 states 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. Their characteristics and use are discussed in paragraphs 2-3-8 through 2-3-13.
What does a red sign with white letters mean on a taxiway?
Per AIM 2-3-8, mandatory instruction signs have a red background with a white inscription and denote an entrance to a runway or critical area, or areas where an aircraft is prohibited from entering. Examples include the runway holding position sign, ILS critical area holding position sign, and the No Entry sign.
What does a runway holding position sign such as “15-33” tell the pilot?
AIM 2-3-8 explains the runway holding position sign contains the designation of the intersecting runway, with numbers arranged to correspond to the respective runway threshold. For example, “15-33” indicates the threshold for Runway 15 is to the left and the threshold for Runway 33 is to the right.