Beacon

When firing in aviation largely stationary light or radio signals for navigation are referred to in the aerospace industry. There are different names such as Start-/Landebahnbefeuerung, approach lights, also obstacle, turning or code beacon.

History

The roots can be found in the beacons of shipping for marking harbor entrances, which served the orientation. From one has with light signals on land ( land fire), and later on fire ships with open fire (tar) or torches were stocked. Today there are still along the coast lighthouses that were built for this purpose.

Aeschylus ( 525-456 BC) describes in the Oresteia, Agamemnon, verses 280-311, the notification of the victory in the Trojan war and the capture of Troy by Fire post about a squadron of beacons over hundreds of kilometers to Argos.

The view of the fire, that is, the visibility luminous objects, the day is about twice as much as the non-illuminated objects. In particular, in cloudy weather, the lights improve the visibility. The development of the Fresnel lens was the decisive breakthrough in the efficiency of light output and enhanced the effect of the beacon. What is proven in shipping, was acquired in a similar form in aviation.

In aviation, the firing was initially the marking of airfields in bad weather. Initially brushwood fires were used, later oil lamps. With the advent of night flights also range fire were introduced as a guide. These were later replaced by Beacon.

Marking of aviation obstacles by firing

With the introduction of scheduled flights was greater independence from the weather, particularly the visibility is required. Obstacles to air navigation area near airports were provided with paints and red warning lights as obstacle - navigation lights ( OBSL = Obstruction Lights). Today obstacles is fueled by various types of fires depending on the size and location of objects. In general, the contour of an object to be fired. The use is governed by the ICAO (International Civil Aviation Organization) and the respective national regulations. The ICAO defined mainly six types:

  • Medium Intensity Obstacle Light, Type A ( 20,000 cd white flashing ) as Tagbefeuerung
  • High Intensity Obstacle Light, Type A ( 200,000 cd white flashing ) as Tag-/Nachtbefeuerung
  • High Intensity Obstacle Light, Type B ( 100,000 cd white flashing ) as Tag-/Nachtbefeuerung

In Germany Type A are used under the name of obstruction lights and objects at higher medium Intensity Obstacle Lights as a means of power obstruction lights usually only Low Intensity Obstacle Light. An exception are the wind turbines, here must be a lamp " W, Red" with an intensity of 2,000 cd be used as night lights. This lamp has a characteristic error code ( at 1 s - 0.5 s off - 1 s on - 1.5 s off). Come on wind turbines means power fire danger systems are used, then these percentages may be reduced with a visibility of more than 5 km to 30 % of the nominal intensity at more than 10 kilometers to 10%. Alternatively, wind turbines can be fired also at the blade tips ( leaf tips Obstruction Light ). Here, the highest sheet is always illuminated, and must be within a range of / -60 ° to be switched from the perpendicular. However, this process is very complex due to the risk of lightning strikes in the rotor blades and is shunned because of problems with the residents - acceptance.

For reliability, LED lamps are used almost exclusively. Previously, most discharge lamps or flash lamps were used. The widespread especially in France on high voltage lines Balisor is not approved for use in Germany. (see: marker lamps for high -voltage power lines )

Previously also equipped with high-pressure xenon lamps rotating headlights ( Skybeamer ) similar to those on lighthouses, used for aviation safety lighting. These are now almost completely disappeared in Germany with the exception of the Stuttgart Television Tower. For guyed masts are occasionally found on the most remote from the mast guying foundations flight safety lamps, which mark the span of the guy ropes.

A special form of aviation safety lighting was implemented in 1939 for the high voltage circuit potential radiating transmitting mast of Germany III transmitter in Herzberg on the Elster. There rotating Skybeamer were no lights on radio mast, but on three small masts installed, alternately beaming the lenticular roof capacity of the transmission mast.

Start-/Landebahn-Befeuerung

In many start and runways lighting systems are introduced to the orientation of the pilots of both sides and in the middle. The side lighting is used as start and runway edge lights (REL = Runway Edge Lights ), the middle called the start and runway centerline lights ( RCLL = Runway Centreline Lights). A center line lighting is realized with inground lamps. A center line lighting is only when weather operations stage II and CAT III duty. The center line lighting is up to 900 m in front of tail white, then alternating red and white and on the last 300 m red ( warning of the approaching end ).

Each located at the two ends of the runway, the runway end lights (REL = Runway End lights ) in red when landing is the threshold to be flying (which does not automatically have to mean the beginning of the web ) Green. The pilot therefore always sees, regardless of which side he flies to, at the beginning of a green lights and at the end of a red. In addition, a staggered thresholds outer chain lighting is used, starting from the edge lights at least five fire over 10 m either side of the airstrip. With precision runways (2 flashes per second) must be used in white on both sides of the threshold flash fire.

The use of directional radiators improves the luminous efficiency and allows the emitting different colors in opposite directions, however, reduces the visibility of the side. On airfields with high traffic runway edge beacons with medium intensity (MRL = Medium Intensity Runway Edge Lights) are often present. Runway edge beacons with high intensity ( HRL = High Intensity Runway Edge Lights) are installed at airports to improve visibility. For occasional night flights on the other hand sufficient a runway edge lights with low intensity (LRL = Low Intensity Runway Edge Lights).

Approach lighting

The approach lighting system (ALS = Approach Lighting System ) is used for estimating height, direction and displacement during landing approach and the transition from instrument approach to visual approach.

Types of approach - fired for:

  • MALSF
  • SSALR
  • ALSF -1
  • ALSF -2

Indicators for the glide angle

Even with an approach to an aerodrome or aircraft carrier, the pilot by means lighting (lamps) is signaled, whether it is too high, too low, or the correct approach corridor. There are for this purpose, the systems:

  • VASI or VASIS approach slope = (Visual Approach Slope Indicator System)
  • PAPI or PAPIS = Precision approach angle firing ( Precision Approach Path Indicator System)

Code beacon

The code beacon sends letters of the airfield by light signals. For military airfields of the Warsaw Pact, the two characters were in Morse code, in addition to the direction of approach in the reverse order.

More lightings

  • ABN = aerodrome beacon ( Aerodrome Beacon ): An aerodrome beacon shall be provided at each aerodrome to be used at night. It must be placed on the aerodrome or in its vicinity. The aerodrome beacon emits white light from a light intensity of at least 20,000 cd. Is the number of light radiations ( flash or flash ) range from 20 to 30 per minute.
  • PAL / PCL = pilot activated lighting side (Pilot Activated Lighting / Pilot Controlled Lighting); at least 2 seconds pressing the microphone button of the radio, the lights will be turned on for about 30 minutes
  • Twyl = taxiway lighting ( taxiway lights ); blue edge lights ( TXE = Taxiway Edge ) and green center line lights ( TXC = taxiway center line ). Taxiway edge lights are omni- fire in the upper or lower floor design. Taxiway center line lights, however, are directed fire under floor design. Inset lights can be run over by aircraft.
  • Firing the wind bag

Others

Markings and lightings for the aviation industry are generally set out in Annex 14 of the ICAO. In Germany, the common principles of the federal and state governments are on the marking and beaconing of aerodromes with instrument air traffic to fruition. Depending on the approval of the square is an appropriate lighting to install. This goes on night mode, non-precision approaches to precision approaches (CAT I / II / III).

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