Navigation light

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A Navigation light is a coloured source of illumination on an aircraft, spacecraft, or waterborne vessel, used to signal a craft's position, heading, and status. Commonly, their placement is mandated by international conventions or civil authorities.

Navigation lighting systems include:

• Right-of-Way lights - On ships, aircraft and manned spacecraft, a red light will be mounted on the left or port side of the craft and a green on the right or starboard side. These help two craft on a collision course determine who has right-of-way: if a pilot sees a craft on a path crossing his own, he will see either its red running light or green running light. If he sees green, he is to the impinging craft's starboard and has the right of way. If the pilot sees the red light, he knows that the approaching craft has the right-of-way, and he is required to deviate from his course to avoid the collision.

• Strobe lights - On aircraft primarily, strobe lights flash a high-intensity burst of white light, to help other pilots recognize the aircraft's position in low-visibility conditions.

Contents 1 Marine navigation lights 1.1 Basic lighting 1.2 Lights of special significance 2 Aviation navigation lights 3 External links 4 References

[edit] Marine navigation lights

In marine navigation Part C of the International Regulations for Preventing Collisions at Sea govern the navigation lights required on a vessel. Also Part B of those regulations cover steering and sailing. There are give-way vessels who are obligated to give way to stand-on vessels that are obligated to maintain current course and bearing. The stand on vessel does not have a right of way in the conventional sense as it is required to maintain its course and speed (except to avoid imminent collision). It is the give way vessel that has the luxury of maneuvering around.

[edit] Basic lighting

To avoid collisions, vessels mount navigation lights that permit other vessels to determine the type and relative angle of a vessel, and thus decide if there is a danger of collision. For example, almost all vessels mount a green light on the starboard (right), a red light on the port (left), and white light masthead and stern lights (multiple masthead lights on large vessels). The lights have defined quadrants throughout which they must be clearly visible, and outside of which they are invisible.

[edit] 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 "Quick Guide" in external links.

• Large vessels mount two forward-and-side facing white 'masthead' lights. These are mounted on masts, funnels or other high structures and the aft light is mounted higher than the forward one.
• Ships at anchor display a single white light (the anchor light) that can be seen from all directions.
• Boats classed as "small" are not compelled to carry navigation lights and may make use of a handheld torch

[edit] Aviation navigation lights

Aircraft navigation lights are placed in a way similar to that of marine vessels, 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.^[1] High-intensity strobe lights are located on the aircraft to aid in collision avoidance.^[2]

Navigation lights in civil aviation are required to be operational and to be turned on from sunset to sunrise. High-intensity white strobe lights are part of the anti-collision light system, as well as the aviation red or white rotating beacon. The anti collision light system (either strobe lights or rotating beacon) is required to be operational and to be turned on for all airplanes built after March 11th 1996 on all aircraft operations.

[edit] External links

• Marine Vessel Navigation Lights - quick guide
• Mnemonics for light pattern recognition
• Navigation lights

[edit] References

1. ^ Federal Aviation Regulation, Part 23 Airworthiness Standards: Normal, Utility, Acrobatic and Commuter Category Airplanes, Subpart F: Equipment--Lights, Section 23.1385 Position Light System Installation. Retrieved on December 1, 2006.
2. ^ Federal Aviation Regulation, Part 23 Airworthiness Standards: Normal, Utility, Acrobatic and Commuter Category Airplanes, Subpart F: Equipment--Lights, Section 23.1401 Anticolllision Light System. Retrieved on December 1, 2006.