Signs installed on airfields to indicate locations, directions, destinations, and the remaining runway distance. The signs also give information and indicate certain mandatory instructions. The various signals are as follows:
i. Mandatory instructions signs. These have a red background with white inscription and are used to denote areas where an aircraft is prohibited from entering and an entrance to a runway critical area. The signs in this category are for indicating runway holding position, runway approach area holding position, ILS (instrument landing system) critical area holding position, and no-entry signs.
ii. Location signs. These signs identify either a taxiway or a runway on which aircraft is located. The signs in this category indicate taxiway locations, runway locations, runway boundaries, and ILS critical boundaries. These signs have yellow inscription with a black background.
iii. Direction signs. These signs have a yellow background with 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 has an arrow indicating the direction of the turn. These signs are arranged clock-wise, starting from the first taxiway on the pilot's left.
iv. Designation signs. These have a yellow background with black inscription, indicating a destination on the airport. Destinations commonly shown are runways, aprons, terminal areas, international areas, and fixed base operations.
v. Information signs. These have a yellow background with black inscription. They provide information such as applicable radio frequencies, areas not visible from ATC (air traffic control), and noise abatement procedures. Information signs include direction signs, location signs, destination signs, runway exit signs, and runway-vacated signs.
vi. Runway distance remaining signs. These have a black background with white inscription indicating the distance of the remainding landing run in thousands of feet. They may be installed on either one or both sides of the runway.
vii. Runway holding position signs. These signs are located at the holding position on taxiways that intersect a runway or on runways that intersect other runways. On taxiways that intersect the beginning of the takeoff runway, only the designation of the takeoff runway appears on the sign, while all other signs designate both runway directions. If the sign is located on a taxiway that intersects the intersection of two runways, both runways are designated. In addition to showing the approximate runway alignment, the arrow indicates the direction to the runway threshold of the designated runway.
viii. Runway approach area holding position signs. These signs are put up if the aircraft are required to hold on a taxiway located in the approach or departure areas. These signs located at the holding position on the taxiway have the designation of the approach end of the runway followed by a dash (-) and the letters APCH.
ix. ILS critical area holding position signs. These signs are used when it is necessary to hold an aircraft on a taxiway at a location other than the normal holding position when the ILS (instrument landing system) is being used.
λ. Aircraft arresting signs. These signs are on those airfields where arrester barriers, or arresting cables, are installed. While there are no signs for the former, the locations of the cables are indicated by a 10-ft (3 m) solid circle painted in identification yellow, 30 ft (9 m) on center, perpendicular to the runway centerline across the entire runway width.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved