Position light

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Oncoming motor ship with three position lights

A position light is a light source of air , water vehicles and space ships , which serves other traffic on adjacent vehicles to point whose position and movement direction to collisions to be avoided. This term encompasses sidelights and stern lights as well as the masthead lights in the case of machine-propelled watercraft.

Colors and sectors

1 From the right, 2 From the front, 3 From the left, 4 Seen from the back
Position lights at Dragon (spaceship)

Aircraft and watercraft have in common that the position lights illuminate three different sectors with different colors:

  • in the direction of travel or flight right in front ( starboard ): green
  • in the direction of travel or flight on the left front ( port ): red
  • to the rear (aft): white

The side lights (green and red) cover an angle of 112.5 ° each on watercraft, 110 ° each on aircraft, the stern light (white) on watercraft the remaining 135 ° of the arc, and 140 ° on aircraft.

Machine-propelled watercraft also have two white masthead lights that outshine the area of ​​the side lights, the rear one being higher than the one in front. Vehicles less than 50 m in length can do without the rear of the two masthead lights.

The rules of avoidance between watercraft and aircraft are signaled by the position lights. Traffic coming from the right with the right of way or right of way is signaled by the green position light, traffic coming from the left is signaled by the red position light. Both position lights are visible from the front and both vehicles have to swerve to starboard or right, from the rear only the white stern light is visible.

Regulations

The lights to be led by aircraft are regulated by way of example in Europe in the Implementing Regulation ( EU) No. 923/2012 ( SERA ). They are mandatory if you want to fly between the end of civil twilight ( ECET ) and the beginning of civil dawn (BCMT). If position lights are available on the aircraft, they must be operated day and night.

The use of lights in watercraft is regulated in the Collision Prevention Regulations ( KVR) and, in Germany, in the Maritime Traffic Regulations (SeeSchStrO). The lights according to these regulations are to be used between sunset and sunrise, as well as during the day in unsightly weather (rain, fog, snowfall), provided that the watercraft are on the high seas or in coastal waters.

Attaching the lights

Aircraft

Green position light on the right wing tip and red collision warning lights on the top and bottom of the fuselage of a Boeing 787 ; the left wing tip and the taxiing light on the nose landing gear are covered
White position light in LED version at the rear of a Socata TBM 910

In the case of an aircraft, the position lights are located on the left and right of the outer wing ends and at the same time form the outer boundary of the aircraft. The white light is at the stern. Some manufacturers have additional position lights attached directly to the left and right of the fuselage. The intensity of the position and strobe lights also penetrate light clouds and fog. This means that the direction and position of neighboring aircraft can be recognized even at night.

Watercraft

Watercraft have the side lights on the sides of the vehicle and the stern light on the stern. According to Rule 21 b KVR, the side lights in a two-color lantern may be placed above the longitudinal axis on a vehicle less than 20 m in length. According to rule 25 b KVR, a sailing craft less than 20 m in length may have sidelights and stern lights combined in a three-color lantern that is attached to or near the top of the mast. However, if such a sailing vehicle drives under engine, it must have the then prescribed lights.

For the technical design of position lights on watercraft, see the main article Position lights .

More lights on watercraft

The position lights described here in the narrower sense only form part of the lights used by watercraft in order to indicate the type of ship, operating status and the like in addition to position and direction of travel, see main article Light guidance .

More lights on aircraft

Collision warning lights

Collision warning lights (Engl. Anti Collision Light (ACL)) is, to a red flashing light (Engl. Beacon Light ), which is usually on the tail or on the fuselage, and a white flash (Engl. Strobe, strobe light ) which the Wing tips of an aircraft is attached. Many aircraft have a second beacon light on the underside of the fuselage and another strobe on the rear of the fuselage . Beacon and strobe lights are synchronized with each other. In older aircraft, an all-round light designed as a beacon light is often used as a collision warning light . Beaconlights are being replaced more and more by pure stroboscopic lamps, strobes . The advantage of these stroboscopic lamps is greater brightness and visibility, which can also be used in poor weather conditions such as B. offers a high level of collision protection in light fog or rain.

In the presence of two bodies of collision warning lights, so Beacon Light and Strobelight showing switched Beacon Lights that the engines are running or the starting of imminent. This is a warning for all persons on the apron to observe the necessary safety distances. In order to avoid unnecessarily dazzling ground staff, the high-intensity stroboscopic lights of the strobes are only switched on when they are rolled onto the slope . In the air, they serve as a visual warning to avoid collisions.

The collision warning light is not the only measure to avoid collisions: commercial aircraft are usually equipped with a Traffic Alert and Collision Avoidance System (TCAS), which gives recommendations to avoid a collision.

In addition to avoiding collisions, the different synchronization , which differs from one another depending on the manufacturer , also has the effect of recognizing aircraft from different manufacturers by the type of flash of their strobes and beacons . For example, on Airbus aircraft of the A300-600 and A310-300 series and later (i.e. A320 / A330 / A340 / A380) the stroboscopic lights flash twice in quick succession, while this only happens once on aircraft from the manufacturer Boeing .

LED technology is now also finding its way into aircraft lighting. For example, the latest Boeing models 787 and 747-8, along with some of the latest generation of business jets, are already equipped with it.

More outdoor lights

Landing light of a Cessna 172

In addition to the position lights on the outside of the aircraft, there are other lighting devices that make it easier for the crew to navigate the aircraft safely, such as powerful landing and taxiing lights as well as lights on the fuselage and the wings for observing sensitive components such as B. the air inlets of the engines or the wing leading edges on ice accumulation. Commercial aircraft also have logo lights that illuminate the vertical tail fin with the airline logo on it with white light. The reason for this is on the one hand to achieve a certain advertising effect and on the other hand to make the aircraft more recognizable when rolling on the ground and to make it easier to distinguish visually for the apron control . The Logo Light headlights are usually built into the top of the horizontal tail fins or in their edge arches.

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