Airway beacon

Last updated

Illustration of Airway beacon, showing designated number. In this example, for units digit "1", Morse code should be ".--" (W). LightLaneTower.jpg
Illustration of Airway beacon, showing designated number. In this example, for units digit "1", Morse code should be ".--" (W).
An aerial lighthouse located in Pansio, Turku, Finland Pansion lentomajakka 2.jpg
An aerial lighthouse located in Pansio, Turku, Finland

An airway beacon (US) or aerial lighthouse (UK and Europe) 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. [1] [2]

Contents

UK and Europe

United Kingdom

The last operational aerial lighthouse in the UK, at the RAF College main building at RAF Cranwell in Lincolnshire College Hall Officers' Mess crop.jpg
The last operational aerial lighthouse in the UK, at the RAF College main building at RAF Cranwell in Lincolnshire

A network of aerial lighthouses was established in the United Kingdom and Europe during the 1920s and 1930s. [3] Use of the lighthouses has declined with the advent of radio navigation aids such as NDB (non-directional beacon), VOR (VHF omnidirectional ranging) and DME (distance measuring equipment). The last operational aerial lighthouse in the United Kingdom is on top of the cupola over the RAF College main hall at RAF Cranwell.[ citation needed ]

Netherlands

Gas holder Goliath in Eindhoven (designated by the letters EH) in the 1930s NIMH - 2011 - 0122 - Aerial photograph of Eindhoven, The Netherlands - 1920 - 1940, Gas holder.jpg
Gas holder Goliath in Eindhoven (designated by the letters EH) in the 1930s
Two gasholders in Leeuwarden. NIMH 2011-3625 luchtfoto van Leeuwarden, Friesland, Nederland, circa 1920-1940.jpg
Two gasholders in Leeuwarden.

In the Netherlands, gas holders were painted with an arrow pointing north and two letters identifying their location.

United States

Remnants of Transcontinental Air Mail Route Beacon 37A, atop a bluff in St. George, Utah, with concrete arrow indicating the direction to the next beacon Transcontinental Air Mail Route Beacon 37A.jpg
Remnants of Transcontinental Air Mail Route Beacon 37A, atop a bluff in St. George, Utah, with concrete arrow indicating the direction to the next beacon

Approximately 1,500 airway beacons were constructed to guide pilots from city to city, [4] [5] covering 18,000 miles (29,000 km). Today, most of the beacons have been removed, but the State of Montana continues to maintain several as navigation aids in mountainous terrain. [6] One beacon is preserved for historical purposes in Saint Paul, Minnesota [7] at the Indian Mounds Park on a bluff overlooking the Mississippi River. [8] A rotating airway beacon has been in continuous operation at the summit of Rocky Butte in Portland, Oregon since 1929, though it was officially decommissioned during the 1960s. Recently, the beacon at Grants, New Mexico was restored for historic preservation, using original items found at other nearby sites. [9]

A large concrete slab, in the shape of an arrow, was located near the base of each beacon. Many of these arrows remain today, some of which are visible from satellite pictures, even in urban settings. [10]

Light characteristics

An airway beacon has two distinct light characteristics: A revolving narrow white light beam about 5 degrees wide in azimuth and a set of fixed colored course lights of about 15 degrees width. [11]

White rotating beacon

The rotating beacon 24 inch (610 mm) parabolic mirror and a 110-volt, 1 kilowatt lamp. [11] spinning at 6 rpm, creating a quick one-tenth second flash every ten seconds. In clear weather they could be seen for 40 miles (64 km). [11] [12] Montana took steps to modernize their beacons, encasing newer light systems in clear domes. [13]

Red or green course lights

Just below the white beacon, a set of red or green course lights point along each airway route. Red lights denote an airway beacon between landing fields while green denotes a beacon adjacent or upon a landing field. [11] These course lights flash a Morse code letter identifying the beacon to the pilot. Each beacon is identified with a sequential number along the airway, and flash the red or green course lights with the Morse code ID of one of 10 letters: W, U, V, H, R, K, D, B, G or M. The letters represent the digits of 1 through 10 (W = 1, ..., M = 10). [11] The course lights turn on for 0.5 second for a dot, 1.5 second for a dash with a 0.5 second between each dot or dash. A pause of 1.5 seconds separates each letter. [14]

To help remember the letters and their sequence number, pilots memorized the following: "When Undertaking Very Hard Routes, Keep Direction By Good Methods." The beacons are depicted on navigation charts along with their number and Morse code pattern. For example, beacon number 15 would have a code digit of 5 (the unit's digit), hence the letter R, and Morse code: "dit dah dit" (·−·). [15]

History

An airway beacon in Saint Paul, Minnesota, built in 1929 and restored in the 1990s. It sits on top of a 110-foot (34 m) steel tower in Indian Mounds Park. Indian Mounds Park Airway Beacon.jpg
An airway beacon in Saint Paul, Minnesota, built in 1929 and restored in the 1990s. It sits on top of a 110-foot (34 m) steel tower in Indian Mounds Park.

Airway beacons in the US were constructed by the Post Office and the Department of Commerce between 1923 and 1933. [12] The Low Frequency Radio Range system began to replace this visual system in 1929. [12] The last visual airway beacon was supposedly shut down in 1973, [12] but a few airway beacons are still operating in Portland, Oregon and Western Montana. [16] Those in Montana are charted on the Great Falls sectional chart. [17] Montana was the last state to officially maintain airway beacons, through the state's Aviation Division. In 2017, the decision was made by Aeronautics Division to discontinue their maintenance of the system, due to the system's obsolete nature and budgetary concerns. The system was to be shut down entirely by December 31, 2021. [18] In spring of 2018, fourteen of the seventeen beacons were shut down by MDT. The Montana Department of Transportation's Communications Bureau took over care of beacons at St. Regis and Lookout Pass. Six beacons are now in the care of the owners of the land they were erected on, six are in the care of a non-profit, Idaho Aviation Heritage, and four are in the care of local governments. [18] Due to their historical significance in the state, the beacons at Homestake Pass, Canyon Resort, MacDonald Pass, Silver Bow, Spokane, Lookout Pass, St. Regis, Whitetail are in the process of being listed on the National Register of Historic Places. The strawberry Mountain beacon was demolished in the summer of 2021. MDT's Aeronautics Division removed the beacon and donated it to the Montana Historical Society. [18]

See also

Related Research Articles

A waypoint is a point or place on a route or line of travel, a stopping point, an intermediate point, or point at which course is changed, the first use of the term tracing to 1880. In modern terms, it most often refers to coordinates which specify one's position on the globe at the end of each "leg" (stage) of an air flight or sea passage, the generation and checking of which are generally done computationally.

<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.

Aviation is the design, development, production, operation, and use of aircraft, especially heavier-than-air aircraft. Articles related to aviation include:

<span class="mw-page-title-main">Non-directional beacon</span> Radio transmitter which emits radio waves in all directions, used as a navigational aid

A non-directional beacon (NDB) or non-directional radio beacon is a radio beacon which does not include inherent directional information. Radio beacons are radio transmitters at a known location, used as an aviation or marine navigational aid. NDB are in contrast to directional radio beacons and other navigational aids, such as low-frequency radio range, VHF omnidirectional range (VOR) and tactical air navigation system (TACAN).

<span class="mw-page-title-main">Automatic direction finder</span> Marine or aircraft radio-navigation instrument

An automatic direction finder (ADF) is a marine or aircraft radio-navigation instrument that automatically and continuously displays the relative bearing from the ship or aircraft to a suitable radio station. ADF receivers are normally tuned to aviation or marine NDBs operating in the LW band between 190 – 535 kHz. Like RDF units, most ADF receivers can also receive medium wave (AM) broadcast stations, though these are less reliable for navigational purposes.

<span class="mw-page-title-main">VHF omnidirectional range</span> Aviation navigation system

Very High Frequency Omnidirectional Range Station (VOR) is a type of short-range radio navigation system for aircraft, enabling aircraft with a receiving unit to determine its position and stay on course by receiving radio signals transmitted by a network of fixed ground radio beacons. It uses frequencies in the very high frequency (VHF) band from 108.00 to 117.95 MHz. Developed in the United States beginning in 1937 and deployed by 1946, VOR became the standard air navigational system in the world, used by both commercial and general aviation, until supplanted by satellite navigation systems such as GPS in the early 21st century. As such, VOR stations are being gradually decommissioned. In 2000 there were about 3,000 VOR stations operating around the world, including 1,033 in the US, but by 2013 the number in the US had been reduced to 967. The United States is decommissioning approximately half of its VOR stations and other legacy navigation aids as part of a move to performance-based navigation, while still retaining a "Minimum Operational Network" of VOR stations as a backup to GPS. In 2015, the UK planned to reduce the number of stations from 44 to 19 by 2020.

<span class="mw-page-title-main">Navigation light</span> Lights on a vessel, aircraft or spacecraft giving information on its position, heading, and status

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. 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).

The Air Commerce Act of 1926 created an Aeronautic Branch of the United States Department of Commerce. Its functions included testing and licensing of pilots, certification of aircraft and investigation of accidents.

<span class="mw-page-title-main">Airway (aviation)</span> Designated route along which aircraft travel between airports

In the United States, airways or air routes are defined by the Federal Aviation Administration (FAA) in two ways:

<span class="mw-page-title-main">Marker beacon</span> Type of VHF radio beacon used in aviation

A marker beacon is a particular type of VHF radio beacon used in aviation, usually in conjunction with an instrument landing system (ILS), to give pilots a means to determine position along an established route to a destination such as a runway.

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

An aerodrome beacon, airport beacon, 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">Aviation obstruction lighting</span> Aircraft obstacle avoidance systems

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">Willows-Glenn County Airport</span> Airport

Willows-Glenn County Airport is a county-owned, public-use airport located one nautical mile (2 km) west of the central business district of Willows, a city in Glenn County, California, United States. This airport is included in the National Plan of Integrated Airport Systems for 2011–2015, which categorized it as a general aviation facility. It is also known as Willows-Glenn Airport.

<span class="mw-page-title-main">Sultan Shoal Lighthouse</span> Lighthouse

The Sultan Shoal Lighthouse was built in 1895 during the time when the late Commander Charles Quentin Gregan Craufurd was the Master Attendant of Singapore. It was built to replace the beacon previously established there.

<span class="mw-page-title-main">Low-frequency radio range</span> Navigation system formerly used by aircraft

The low-frequency radio range, also known as the four-course radio range, LF/MF four-course radio range, A-N radio range, Adcock radio range, or commonly "the range", was the main navigation system used by aircraft for instrument flying in the 1930s and 1940s, until the advent of the VHF omnidirectional range (VOR), beginning in the late 1940s. It was used for en route navigation as well as instrument approaches and holds.

<span class="mw-page-title-main">Transcontinental Airway System</span> Navigational aid deployed in the United States

The Transcontinental Airway System was a navigational aid deployed in the United States during the 1920s.

An aerobeacon is a light assembly used to create a fixed or flashing signal visible over long distances. It consists of a high intensity electric lamp mounted with a focusing device in a cylindrical housing, which usually is rotated on a vertical axis by an electric motor. The sweep of the narrow beam thus produced gives the flashing effect. Aerobeacons were originally developed for aviation use, mostly as aerodrome beacons, but they also saw extensive use in lighthouses. They were far less expensive to manufacture and maintain than classic glass Fresnel lenses, and much more durable; they could be mounted and exposed to the weather. Historic models include the DCB-24, which used a single parabolic reflector; the DCB-224, a double-beamed version of the DCB-24; and the DCB-36, which used a system of plastic Fresnel type lenses. Manufacturers included Carlisle & Finch in Cincinnati and the Crouse-Hinds Company in Syracuse, New York. Aerobeacons have replaced fragile glass Fresnel lenses in many lighthouses and are still widely used in other applications.

<span class="mw-page-title-main">Semaphore</span> Mechanical apparatus used to send messages

Semaphore is the use of an apparatus to create a visual signal transmitted over distance. A semaphore can be performed with devices including: fire, lights, flags, sunlight, and moving arms. Semaphores can be used for telegraphy when arranged in visually connected networks, or for traffic signalling such as in railway systems, or traffic lights in cities.

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

A Pundit Beacon or Landmark Beacon was an airfield navigational and identification beacon, used by the British Royal Air Force (RAF) in the period around World War II.

<span class="mw-page-title-main">Lindbergh Beacon (Los Angeles)</span> Aircraft beacon on Los Angeles City Hall

The Lindbergh Beacon, an aircraft beacon atop the Los Angeles City Hall, operated nightly from April 26, 1928, until just after the attack on Pearl Harbor. It was restored to its original condition in 2001, and Los Angeles magazine described it as "a tiara of light atop our beautifully restored Los Angeles City Hall." City officials now occasionally put the beacon into operation for special occasions such as the year-end holidays.

References

  1. "The Aerial Lighthouse". Flight. Retrieved 29 November 2011.
  2. "LIGHTHOUSE FOR AIRSHIPS.; One Already Installed at Spandau for German Army Flights". The New York Times . 5 June 1910.
  3. "Aerial Lighthouses". Archived from the original on 22 September 2021. Retrieved 15 March 2021.
  4. "Airway Beacons List - Eastern US". Roger Barnes. Archived from the original on 30 January 2012. Retrieved 4 April 2012.
  5. "Airway Beacons List - Western U.S." Roger Barnes. Archived from the original on 30 January 2012. Retrieved 4 April 2012.
  6. Savage, Jason. "Airway Beacons" . Retrieved 5 April 2012.
  7. 1 2 Cosimini, Greg (9 July 1999). "Indian Mounds Park "Airway" Beacon". University of Minnesota. Archived from the original on 24 January 2008. Retrieved 28 August 2007.
  8. Coordinates are 44.94608378510258, -93.05781483650216
  9. At least one beacon to be fully restored as a local museum.beacon buildings Archived 2013-09-30 at the Wayback Machine
  10. Aviation Navigation Arrows in Washington County, Utah
  11. 1 2 3 4 5 Wood, Charles. "How it Began". Charles Wood. Retrieved 4 April 2012.
  12. 1 2 3 4 "The Evolution of Airway Lights and Electronic Navigation Aids". U.S. Centennial of Flight Commission. Archived from the original on 30 September 2007. Retrieved 28 August 2007.
  13. Spivey, Brenda (1993). Airway Beacons, an Integral Part of Montana's Night VFR Navigational System: Past History, Present Service and Present Value (PDF). Embry Riddle Aeronautical University. p. 21. Archived from the original (PDF) on 25 November 2013. Retrieved 5 April 2012.
  14. FAA Advisory Circular Number 170/6850-1. FAA. 1968.
  15. Majors, Beverly (7 July 2009). "Beacon House was part of changes in air transportation". Oak Ridge, TN: OakRidger.com. Associated Press. Archived from the original on 28 September 2011. Retrieved 21 February 2012.
  16. "Airway Beacons". Montana Department of Transportation. Archived from the original on 1 June 2011. Retrieved 21 February 2012. Today, Montana is the only state that still utilizes part of this historic network through our rugged western mountains. Division personnel climb and maintain approximately 19 of these beacons on a regular schedule, also providing ownership and ground leases for their operation.
  17. Rogan, Michael (2011). Airway Support Officer. All of our airway beacons and the associated code are listed on any current Great Falls sectional[. . .]
  18. 1 2 3 "Airway Beacons -The End of an Era". Montana Department of Transportation. Archived from the original on 2 September 2022. Retrieved 22 January 2023.