{{Short description|Beacon installed at an airport}} {{distinguish|Airway beacon}} {{about|identifying airports to overhead aircraft|sending information to travellers' phones|Bluetooth low energy beacon}}
[[File:Rotating beacon at the Alberta Aviation Museum.JPG|thumb|A portable rotating beacon on display at the Alberta Aviation Museum]] An '''aerodrome beacon''', '''airport beacon''', '''rotating beacon''' or '''aeronautical beacon''' is a beacon installed at an airport or aerodrome to indicate its location to aircraft pilots at night.
An aerodrome beacon is mounted on top of a towering structure, often a control tower, above other buildings of the airport. It produces flashes similar to that of a lighthouse.
Airport and heliport beacons are designed in such a way to make them most effective from one to ten degrees above the horizon; however, they can be seen well above and below this peak spread. The beacon may be an omnidirectional flashing xenon strobe, or it may be an aerobeacon rotating at a constant speed which produces the visual effect of flashes at regular intervals. Flashes may be of one, two, or three alternating colors.
==In the United States== [[File:KBTP Beacon.jpg|thumb|An active beacon at Pittsburgh-Butler Regional Airport, Pennsylvania.]] In the United States, the Federal Aviation Administration (FAA) has established the following rules for airport beacons:<ref name="aim 2-1">{{cite web |url=https://www.faa.gov/air_traffic/publications/atpubs/aim_html/chap2_section_1.html |title = Aeronautical Information Manual |date = 2019-08-15 |access-date = 2019-08-31 |publisher = Federal Aviation Administration |author = AJV-8, Air Traffic Procedures | pages = 2–1–10 |no-pp = y}}</ref>
'''Flashing rates''' # 24 to 30 per minute for beacons marking airports, landmarks, and points on Federal airways # 30 to 45 per minute for beacons marking heliports
'''Color combinations''' # White and Green — Lighted land airport # Green alone* — Lighted land airport # White and Yellow — Lighted water airport # Yellow alone* — Lighted water airport # Green, Yellow, and White — Lighted heliport # White, White, Green** — Military Airport # White, Green, Amber — Hospital and/or Emergency Services Heliport
:<nowiki>*</nowiki>Green alone or yellow alone is used only in connection with a white-and-green or white-and-yellow beacon display, respectively.
:<nowiki>**</nowiki>Military airport beacons flash alternately white and green, but are differentiated from civil beacons by two quick white flashes between the green flashes.
In Class B, C, D, and E surface areas, operation of the airport beacon between sunrise and sunset often indicates that the ground visibility is less than 3 miles and/or the ceiling is less than 1,000 feet. This is true particularly at locations where beacon controls are available to air traffic control personnel;<ref name=".65 3-4">{{cite web |url=https://www.faa.gov/air_traffic/publications/atpubs/atc_html/chap3_section_4.html |title = FAA JO 7110.65Y – Air Traffic Control |date = 2019-08-15 |access-date = 2019-08-31 |publisher = Federal Aviation Administration |author = AJV-8, Air Traffic Procedures | pages = 3–4–18 |no-pp = y}}</ref> however there is no regulation requiring daytime operation.<ref name="aim 2-1"/>
At some locations with operating control towers, ATC personnel turn the beacon on or off with controls in the tower. At many airports the airport beacon is turned on by a photoelectric cell or time clocks, and ATC personnel cannot control them.<ref name="aim 2-1"/>
==In Canada== In Canada, the regulations are different. Lighted aerodromes are equipped with white single flash beacons operating at a frequency of 20 to 30 flashes per minute. Heliports with beacons exhibit the morse letter H (4 short flashes) at a rate of 3 to 4 groups per minute.<ref>{{cite web|url=http://www.tc.gc.ca/CivilAviation/publications/tp14371/AGA/7-1.htm |author=Transport Canada |title=TC AGA |date=23 October 2008 |url-status=dead |archive-url=https://web.archive.org/web/20080617185432/http://www.tc.gc.ca/CivilAviation/publications/tp14371/AGA/7-1.htm |archive-date=17 June 2008 }}</ref>
==See also== {{commons category}} *Index of aviation articles *Instrument landing system, for the radio-frequency beacons used to locate aircraft.
==Notes== {{reflist}}
==External links== * [http://www.archive.org/details/buildingtechnologyheritagelibrary?tab=collection&query=airport+lighting Collection of airport lighting trade catalogs from the Building Technology Heritage Library]
Category:Air traffic control Category:Beacons