Navigation light

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Basic lighting configuration. 2, a vessel facing directly towards observer; 4, vessel facing away from the observer Propmec50.PNG
Basic lighting configuration. 2, a vessel facing directly towards observer; 4, vessel facing away from the observer
Red and green navigation lights on an F-22 Raptor Raptors refuel 140926-F-ML224-004.jpg
Red and green navigation lights on an F-22 Raptor
Red and green bottom navigation lights on SpaceX Dragon Dragon approaches the ISS (32238998824).jpg
Red and green bottom navigation lights on SpaceX Dragon

A navigation light, also known as a running or position light, is a source of illumination on a watercraft, aircraft or spacecraft, meant to give information on the craft's position, heading, or status. [1] Some navigation lights are colour-coded red and green to aid traffic control by identifying the craft's orientation. Their placement is mandated by international conventions or civil authorities such as the International Maritime Organization (IMO).


A common misconception is that marine or aircraft navigation lights indicate which of two approaching vessels has the "right of way" as in ground traffic; this is never true. However, the red and green colours are chosen to indicate which vessel has the duty to "give way" or "stand on" (obligation to hold course and speed). Consistent with the ground traffic convention, the rightmost of the two vehicles is usually given stand-on status and the leftmost must give way. Therefore a red light is used on the (left (port)) side to indicate "you must give way"; and a green light on the right (starboard) side indicates "I will give way; you must stand on". In case of two power-driven vessels approaching head-on, both are required to give way.

Marine navigation

In 1838 the United States passed an act requiring steamboats running between sunset and sunrise to carry one or more signal lights; colour, visibility and location were not specified. In 1846 the United Kingdom passed legislation enabling the Lord High Admiral to publish regulations requiring all sea-going steam vessels to carry lights. [2] The admiralty exercised these powers in 1848 and required steam vessels to display red and green sidelights as well as a white masthead light whilst under way and a single white light when at anchor. [3] In 1849 the U.S. Congress extended the light requirements to sailing vessels.

In 1889 the United States convened the first International Maritime Conference to consider regulations for preventing collisions. The resulting Washington Conference Rules were adopted by the U.S. in 1890 and became effective internationally in 1897. Within these rules was the requirement for steamships to carry a second mast head light. The international 1948 Safety of Life at Sea Conference recommended a mandatory second masthead light solely for power-driven vessels over 150 feet (46 m) in length and a fixed sternlight for almost all vessels. The regulations have changed little since then. [4]

The International Regulations for Preventing Collisions at Sea (COLREGs) established in 1972 stipulates the requirements for navigation lights required on a vessel.

Basic lighting

Watercraft navigation lights must permit other vessels to determine the type and relative angle of a vessel, and thus decide if there is a danger of collision. In general, sailing vessels are required to carry a green light that shines from dead ahead to 2 points (22+12°) abaft [note 1] the beam on the starboard side (the right side from the perspective of someone on board facing forward), a red light from dead ahead to two points abaft the beam on the port side (left side) and a white light that shines from astern to two points abaft the beam on both sides. Power driven vessels in addition to these lights, must carry either one or two (depending on length) white masthead lights that shine from ahead to two points abaft the beam on both sides. If two masthead lights are carried then the aft one must be higher than the forward one.

Small power-driven vessels (under 12 metres (39 ft)) may carry a single all-round white light in place of the two or three white lights carried by larger vessels, they must also carry red and green navigation lights. Vessels under 7 metres (23 ft) with a maximum speed of less than 7 knots (13 km/h; 8.1 mph) are not required to carry navigation lights, but must be capable of showing a white light. [5] Hovercraft at all times and some boats operating in crowded areas may also carry a yellow flashing beacon for added visibility during day or night.

Lights of special significance

In addition to red, white and green running lights, a combination of red, white and green mast lights placed on a mast higher than all the running lights, and viewable from all directions, may be used to indicate the type of craft or the service it is performing. See "User Guide" in external links.

Aviation navigation

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Navigation lights
Aft light
Anti-collision strobe lights
Logo light Jet-liner's lights 1 N.PNG
  1. Navigation lights
  2. Aft light
  3. Anti-collision strobe lights
  4. Logo light

Aircraft are fitted with external navigational lights similar in purpose to those required on watercraft. [6] These are used to signal actions such as entering an active runway or starting up an engine. Historically, incandescent bulbs have been used to provide light, however recently light-emitting diodes have been used.

Aircraft navigation lights follow the convention of marine vessels established a half-century earlier, with a red navigation light located on the left wingtip leading edge and a green light on the right wingtip leading edge. A white navigation light is as far aft as possible on the tail or each wing tip. [7] High-intensity strobe lights are located on the aircraft to aid in collision avoidance. [8] Anti-collision lights are flashing lights on the top and bottom of the fuselage, wingtips and tail tip. Their purpose is to alert others when something is happening that ground crew and other aircraft need to be aware of, such as running engines or entering active runways.

In civil aviation, pilots must keep navigation lights on from sunset to sunrise, even after engine shutdown when at the gate. High-intensity white strobe lights are part of the anti-collision light system, as well as the red flashing beacon.

All aircraft built after 11 March 1996 must have an anti-collision light system (strobe lights or rotating beacon) turned on for all flight activities in poor visibility. The anti-collision system is recommended in good visibility, where only strobes and beacon are required can use white (clear) lights to increase conspicuity during the daytime. For example, just before pushback, the pilot must keep the beacon lights on to notify ground crews that the engines are about to start. These beacon lights stay on for the duration of the flight. While taxiing, the taxi lights are on. When coming onto the runway, the taxi lights go off and the landing lights and strobes go on. When passing 10,000 feet, the landing lights are no longer required, and the pilot can elect to turn them off. The same cycle in reverse order applies when landing. Landing lights are bright white, forward and downward facing lights on the front of an aircraft. Their purpose is to allow the pilot to see the landing area, and to allow ground crew to see the approaching aircraft.

Civilian commercial airliners also have other non-navigational lights. These include logo lights, which illuminate the company logo on the tail fin. These lights are optional to turn on, though most pilots switch them on at night to increase visibility from other aircraft. Modern airliners also have a wing light. These are positioned on the outer side just in front of the engine cowlings on the fuselage. These are not required to be on, but in some cases pilots turn these lights on for engine checks and also while passengers board the aircraft for better visibility of the ground near the aircraft. While seldom seen, the International Code of Signals allows for the exclusive use of a flashing blue lights (60 to 100 flashes/minute) and visible from as many directions as possible, by medical aircraft to signal their identity. [9]

Spacecraft navigation

In 2011, ORBITEC developed the first light-emitting diode (LED) system for use as running lights on spacecraft. Currently, Cygnus spacecraft, which are uncrewed transport vessels designed for cargo transport to the International Space Station, utilize a navigational lighting system consisting of five flashing high power LED lights. [10] The Cygnus displays a flashing red light on the port side of the vessel, a flashing green on the starboard side of the vessel, two flashing white lights on the top and one flashing yellow on the bottom side of the fuselage.[ citation needed ]

The SpaceX Dragon and Dragon 2 spacecraft also feature a flashing strobe along with red and green lights.

See also


  1. abaft: to the rear/closer to stern/'aft'

Related Research Articles

A beacon is an intentionally conspicuous device designed to attract attention to a specific location. A common example is the lighthouse, which draws attention to a fixed point that can be used to navigate around obstacles or into port. More modern examples include a variety of radio beacons that can be read on radio direction finders in all weather, and radar transponders that appear on radar displays.

<span class="mw-page-title-main">Belisha beacon</span> Design of lamp

A Belisha beacon is an amber-coloured globe lamp atop a tall black and white striped pole, marking pedestrian crossings of roads in the United Kingdom, Ireland, and other countries historically influenced by Britain, such as Hong Kong, Malta, and Singapore. The beacons were named after Leslie Hore-Belisha (1893–1957), the Minister of Transport who, in 1934, added beacons to pedestrian crossings, marked by large metal studs in the road surface. These crossings were later painted in black and white stripes, and thus are known as zebra crossings. Legally, pedestrians have priority on such crossings.

<span class="mw-page-title-main">Landing</span> Transition from being in flight to being on a surface

Landing is the last part of a flight, where a flying animal, aircraft, or spacecraft returns to the ground. When the flying object returns to water, the process is called alighting, although it is commonly called "landing", "touchdown" or "splashdown" as well. A normal aircraft flight would include several parts of flight including taxi, takeoff, climb, cruise, descent and landing.

<span class="mw-page-title-main">Instrument landing system</span> Ground-based visual aid for landing

In aviation, the instrument landing system (ILS) is a precision radio navigation system that provides short-range guidance to aircraft to allow them to approach a runway at night or in bad weather. In its original form, it allows an aircraft to approach until it is 200 feet (61 m) over the ground, within a 12 mile (800 m) of the runway. At that point the runway should be visible to the pilot; if it is not, they perform a missed approach. Bringing the aircraft this close to the runway dramatically increases the range of weather conditions in which a safe landing can be made. Other versions of the system, or "categories", have further reduced the minimum altitudes, runway visual ranges (RVRs), and transmitter and monitoring configurations designed depending on the normal expected weather patterns and airport safety requirements.

<span class="mw-page-title-main">Strobe light</span> Device producing regular flashes of light

A strobe light or stroboscopic lamp, commonly called a strobe, is a device used to produce regular flashes of light. It is one of a number of devices that can be used as a stroboscope. The word originated from the Ancient Greek στρόβος (stróbos), meaning "act of whirling".

A distress signal, also known as a distress call, is an internationally recognized means for obtaining help. Distress signals are communicated by transmitting radio signals, displaying a visually observable item or illumination, or making a sound audible from a distance.

<span class="mw-page-title-main">Taxiway</span>

A taxiway is a path for aircraft at an airport connecting runways with aprons, hangars, terminals and other facilities. They mostly have a hard surface such as asphalt or concrete, although smaller general aviation airports sometimes use gravel or grass.

<span class="mw-page-title-main">Sector light</span> Man-made pilotage and position fixing aid

A sector light is a man-made pilotage and position fixing aid that consists of strictly delineated horizontal angle light beams to guide water-borne traffic through a safe channel at night in reasonable visibility. Sector lights are most often used for safe passage through shallow or dangerous waters. This may be when leaving or entering harbour. Nautical charts give all the required information.

<span class="mw-page-title-main">Wing tip</span> Part of an aircraft

A wing tip is the part of the wing that is most distant from the fuselage of a fixed-wing aircraft.

<span class="mw-page-title-main">Emergency vehicle lighting</span> Visual warning lights fitted to a vehicle

Emergency vehicle lighting, also known as simply emergency lighting or emergency lights, is a type of vehicle lighting used to visually announce a vehicle's presence to other road users. A sub-type of emergency vehicle equipment, emergency vehicle lighting is generally used by emergency vehicles and other authorized vehicles in a variety of colors.

<span class="mw-page-title-main">Emergency vehicle equipment</span> Equipment used by emergency vehicles

Emergency vehicle equipment is any equipment fitted to, or carried by, an emergency vehicle, other than the equipment that a standard non-emergency vehicle is fitted with.

<span class="mw-page-title-main">Aerodrome beacon</span> Beacon installed at an airport

An aerodrome beacon or rotating beacon or aeronautical beacon is a beacon installed at an airport or aerodrome to indicate its location to aircraft pilots at night.

<span class="mw-page-title-main">Approach lighting system</span> Runway lighting installed on the approach end which extends beyond the runway

An approach lighting system (ALS) is a lighting system installed on the approach end of an airport runway and consisting of a series of lightbars, strobe lights, or a combination of the two that extends outward from the runway end. ALS usually serves a runway that has an instrument approach procedure (IAP) associated with it and allows the pilot to visually identify the runway environment and align the aircraft with the runway upon arriving at a prescribed point on an approach.

<span class="mw-page-title-main">Navigational aid</span> Marker to assist in safe passage making

A navigational aid (NAVAID), also known as aid to navigation (ATON), is any sort of signal, markers or guidance equipment which aids the traveler in navigation, usually nautical or aviation travel. Common types of such aids include lighthouses, buoys, fog signals, and day beacons.

<span class="mw-page-title-main">Airway beacon</span> Rotating light assembly mounted atop a tower

An airway beacon (US) or aerial lighthouse was a rotating light assembly mounted atop a tower. These were once used extensively in the United States for visual navigation by airplane pilots along a specified airway corridor. In Europe, they were used to guide aircraft with lighted beacons at night.

Aviation obstruction lighting is used to enhance the visibility of structures or fixed obstacles which may conflict with the safe navigation of aircraft. Obstruction lighting is commonly installed on towers, buildings, and even fences located in areas where aircraft may be operating at low altitudes. In certain areas, some aviation regulators mandate the installation, operation, color, and/or status notification of obstruction lighting. For maximum visibility and collision-avoidance, these lighting systems commonly employ one or more high-intensity strobe or LED devices which can be seen by pilots from many miles away from the obstruction.

<span class="mw-page-title-main">Landing lights</span> Aircraft lights

Landing lights are lights, mounted on aircraft, that illuminate the terrain and runway ahead during takeoff and landing, as well as being used as a collision avoidance measure against other aircraft and bird strikes.

An annunciator panel, also known in some aircraft as the Centralized Warning Panel (CWP) or Caution Advisory Panel (CAP), is a group of lights used as a central indicator of status of equipment or systems in an aircraft, industrial process, building or other installation. Usually, the annunciator panel includes a main warning lamp or audible signal to draw the attention of operating personnel to the annunciator panel for abnormal events or condition.

Anti-collision lights, also known as Beacon lights or Strobe lights are a set of lights required on every aircraft to improve visibility to others, as well as collision avoidance measures by warning other pilots. Historically they have used incandescent bulbs, but recently Light-emitting diodes have been used.

BLITTS is a mnemonic used by some aircraft pilots to run an aircraft checklist during line-up or before lining up to takeoff.


  1. Wragg, David W. (1973). A Dictionary of Aviation (first ed.). Osprey. p. 200. ISBN   9780850451634.
  2. 9th and 10th Vic. c. 100: "An act for the regulation of steam navigation, and for requiring sea-going vessels to carry boats, pp. 623–624, retrieved 6 July 2019
  3. "Steamers' lights – to prevent collision". The London Gazette . No. 20876. 11 July 1848. p. 2606.
  4. Handbook of the Nautical Rules of the Road Llana and Wisneskey
  5. "Amalgamated International & U.S. Inland Navigation Rules: Part C - Lights and Shapes". United States Coast Guard Navigation Center. Retrieved July 18, 2022.{{cite web}}: CS1 maint: url-status (link)
  6. "AC 20-30B - Aircraft Position Light and Anticollision Light Installations – Document Information". Retrieved 6 April 2018.
  7. "14 CFR 25.1385, "Position light system installation"". Archived from the original on 2017-09-20. Retrieved 2012-12-09.
  8. "14 CFR 23.1401, "Anticollision light system"". Archived from the original on 2017-09-20. Retrieved 2012-12-09.
  9. page 146
  10. "ORBITEC Delivers First-Ever LED Lighting System for Orbital Science's Cygnus Module Spacecraft Navigation Lighting". Archived from the original on 2013-08-20. Retrieved 2013-04-13.