Editing Navigation light (section)

==Aviation navigation==
[[File:Jet-liner's lights 1 N.PNG|thumb|right|upright|{{image key |list type = ordered |thumb size = narrow
| Navigation lights
| Aft light
| Anti-collision strobe lights
| Logo light
}}]]
[[Aircraft]] are fitted with external navigational lights similar in purpose to those required on watercraft.<ref>{{cite web|url=https://www.faa.gov/regulations_policies/advisory_circulars/index.cfm/go/document.information/documentID/22569|title=AC 20-30B - Aircraft Position Light and Anticollision Light Installations – Document Information|website=www.faa.gov|access-date=6 April 2018}}</ref> These are used to signal actions such as entering an active runway or starting up an engine. Historically, [[Incandescent light bulb|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.<ref>{{
cite web
 |url         = http://www.ecfr.gov/cgi-bin/text-idx?c=ecfr&SID=93d71915d59dec9ae7d43f0255dd12a3&rgn=div8&view=text&node=14:1.0.1.3.11.6.195.29&idno=14
 |title       = 14 CFR 25.1385, "Position light system installation"
 |access-date  = 2012-12-09
 |url-status     = live
 |archive-url  = https://web.archive.org/web/20170920181005/https://www.ecfr.gov/cgi-bin/text-idx?c=ecfr&SID=93d71915d59dec9ae7d43f0255dd12a3&rgn=div8&view=text&node=14%3A1.0.1.3.11.6.195.29&idno=14
 |archive-date = 2017-09-20
}}</ref> High-intensity strobe lights are located on the aircraft to aid in [[Anti-collision_light|collision avoidance]].<ref>{{
cite web
 |url         = http://www.ecfr.gov/cgi-bin/text-idx?c=ecfr&SID=93d71915d59dec9ae7d43f0255dd12a3&rgn=div8&view=text&node=14:1.0.1.3.11.6.195.37&idno=14
 |title       = 14 CFR 23.1401, "Anticollision light system"
 |access-date  = 2012-12-09
 |url-status     = live
 |archive-url  = https://web.archive.org/web/20170920181006/https://www.ecfr.gov/cgi-bin/text-idx?c=ecfr&SID=93d71915d59dec9ae7d43f0255dd12a3&rgn=div8&view=text&node=14%3A1.0.1.3.11.6.195.37&idno=14
 |archive-date = 2017-09-20
}}</ref> 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 flashing blue lights (60 to 100 flashes/minute), visible from as many directions as possible, by medical aircraft to signal their identity.<ref>http://www.seasources.net/PDF/PUB102.pdf page 146</ref>