San Jose, California
San Jose the City of San José, is an economic and political center of Silicon Valley, the largest city in Northern California. With an estimated 2017 population of 1,035,317, it is the third-most populous city in California and the tenth-most populous in United States. Located in the center of the Santa Clara Valley, on the southern shore of San Francisco Bay, San Jose covers an area of 179.97 square miles. San Jose is the county seat of Santa Clara County, the most affluent county in California and one of the most affluent counties in the United States. San Jose is the most populous city in both the San Francisco Bay Area and the San Jose-San Francisco-Oakland Combined Statistical Area, which contain 7.7 million and 8.7 million people respectively. San Jose is a global city, notable as a center of innovation, for its affluence, Mediterranean climate, high cost of living. San Jose's location within the booming high tech industry, as a cultural and economic center has earned the city the nickname "Capital of Silicon Valley".
San Jose is one of the wealthiest major cities in the United States and the world, has the third highest GDP per capita in the world, according to the Brookings Institution. The San Jose Metropolitan Area has the most millionaires and the most billionaires in the United States per capita. With a median home price of $1,085,000, San Jose has the most expensive housing market in the country and the fifth most expensive housing market in the world, according to the 2017 Demographia International Housing Affordability Survey. Major global tech companies including Cisco Systems, eBay, Adobe Systems, PayPal, Samsung, Hewlett Packard Enterprise, Western Digital maintain their headquarters in San Jose, in the center of Silicon Valley. Before the arrival of the Spanish, the area around San Jose was inhabited by the Tamien nation of the Ohlone peoples of California. San Jose was founded on November 29, 1777, as the Pueblo de San José de Guadalupe, the first city founded in the Californias, it became a part of Mexico in 1821 after the Mexican War of Independence.
Following the American Conquest of California during the Mexican–American War, the territory was ceded to the United States in 1848. After California achieved statehood two years San Jose became the state's first capital. Following World War II, San Jose experienced an economic boom, with a rapid population growth and aggressive annexation of nearby cities and communities carried out in the 1950s and 1960s; the rapid growth of the high-technology and electronics industries further accelerated the transition from an agricultural center to an urbanized metropolitan area. Results of the 1990 U. S. Census indicated that San Jose had surpassed San Francisco as the most populous city in Northern California. By the 1990s, San Jose and the rest of Silicon Valley had become the global center for the high tech and internet industries, making it California's fastest-growing economy; the Santa Clara Valley has been home to the Tamyen group of the Ohlone people since around 4,000 BCE. The Tamyen spoke Tamyen language of the Ohlone language family.
With the Spanish colonization of California, the majority of the Tamyen came to inhabit Mission Santa Clara de Asís and Mission San José. California was claimed as part of the Spanish Empire in 1542, when explorer Juan Rodríguez Cabrillo charted the Californian coast. During this time and Baja California were administered together as Province of the California. For nearly 200 years, the Californias were sparsely populated and ignored by the government of the Viceroyalty of New Spain in Mexico City. Only in 1769 was Northern California surveyed by Spanish authorities, with the Portolá Expedition. In 1776, the Californias were included as part of the Captaincy General of the Provincias Internas, a large administrative division created by José de Gálvez, Spanish Minister of the Indies, in order to provide greater autonomy for the Spanish Empire's populated and ungoverned borderlands; that year, King Carlos III of Spain approved an expedition by Juan Bautista de Anza to survey the San Francisco Bay Area, in order to choose the sites for two future settlements and their accompanying mission.
First he chose the site for a military settlement in San Francisco, for the Royal Presidio of San Francisco, Mission San Francisco de Asís. On his way back to Mexico from San Francisco, de Anza chose the sites in Santa Clara Valley for a civilian settlement, San Jose, on the eastern bank of the Guadalupe River, a mission on its western bank, Mission Santa Clara de Asís. San Jose was founded as California's first civilian settlement on November 29, 1777, as the Pueblo de San José de Guadalupe by José Joaquín Moraga, under orders of Antonio María de Bucareli y Ursúa, Viceroy of New Spain. San Jose served as a strategic settlement along El Camino Real, connecting the military fortifications at the Monterey Presidio and the San Francisco Presidio, as well as the California mission network. In 1791, due to the severe flooding which characterized the pueblo, San Jose's settlement was moved a mile south, centered on the Pueblo Plaza. In 1800, due to the growing population in the northern part of the Californias, Diego de Borica, Governor of the Californias split the province into two parts: Alta California, which would become a U.
S. state, Baja California, which would become two Mexican states. San Jose became part of the First M
Hayward is a city located in Alameda County, California in the East Bay subregion of the San Francisco Bay Area. With a 2014 population of 149,392, Hayward is the sixth largest city in the Bay Area and the third largest in Alameda County. Hayward was ranked as the 37th most populous municipality in California, it is included in the San Francisco–Oakland–Fremont Metropolitan Statistical Area by the US Census. It is located between Castro Valley and Union City, lies at the eastern terminus of the San Mateo–Hayward Bridge; the city was devastated early in its history by the 1868 Hayward earthquake. From the early 20th century until the beginning of the 1980s, Hayward's economy was dominated by its now defunct food canning and salt production industries. Human habitation of the greater East Bay, including Hayward, dates from at least 4000 BC; the most recent pre-European inhabitants of the Hayward area were the Native American Ohlone people. In the 19th century, the land, now Hayward became part of Rancho San Lorenzo, a Spanish land grant to Guillermo Castro, in 1841.
The site of his home was on the former El Camino Viejo, or Castro Street between C and D Streets, but the structure was damaged in the 1868 Hayward earthquake, with the Hayward Fault running directly under its location. Most of the city's structures were destroyed in the earthquake, the last major earthquake on the fault. In 1930, that site was chosen for the construction of the City Hall, which served the city until 1969. William Dutton Hayward arrived during the gold rush and "squatted" as he began to build a house next to the creek at the site of the old Polamares School. Guillermo Castro's Vaqueros told Hayward to get off of Castro's property. William did leave, but asked to buy a piece of his land. Castro sold him the area of what was east of Castro Street, now Mission Blvd and north side of A Street. William Hayward built a grand hotel on the property, he and his wife ran the hotel, which burned to the ground around 1916. Hayward was known as "Hayward's" as "Haywood" as "Haywards", as "Hayward".
There is some disagreement as to. Most historians believe it was named for William Dutton Hayward, who opened a hotel there in 1852; the U. S. Geological Survey Geographic Names Information System states the city was named after Alvinza Hayward, a millionaire from the California Gold Rush. Regardless of which Hayward the area was named for, the name was changed to "Haywood" when the post office was first established in 1860. Castro emigrated to Chile with most of his family in 1864, his name survives in the community of Castro Valley, located in the valley next to Hayward, which Castro used to pasture his cattle. The ranch was sold to various locals, William Hayward among them. William Hayward's fortunes took a turn for the grander when he constructed a resort hotel, which grew to a hundred rooms; the surrounding area came to be called "Hayward's" after the hotel. William Hayward became the road commissioner for Alameda County, he used his authority to influence the construction of roads in his own favor.
He was an Alameda County supervisor. In 1876, a town was chartered by the State of California under the name of "Haywards"; the name of the post office was able to change because of the loss of the apostrophe before the "s". This change occurred in 1880, it remained "Haywards" until 1910 when the "s" was dropped. William Hayward died in 1891. Hayward grew throughout the late 19th century, with an economy based on agriculture and tourism. Important crops were tomatoes, peaches and apricots. Hunt Brothers Cannery opened in 1895. Chicken and pigeon raising played important roles in the economy. A rail line between Oakland and San Jose, the South Pacific Coast Railroad, was established, but was destroyed in the 1868 earthquake; the Hayward shore of the Bay was developed into extensive salt evaporation ponds, was one of the most productive areas in the world, with Leslie Salt one of the largest companies. The first San Mateo–Hayward Bridge opened in 1929, connecting the city to the San Francisco Peninsula.
During the 1930s, the Harry Rowell Rodeo Ranch, now within the bounds of Castro Valley, drew rodeo cowboys from across the continent, western movie actors such as Slim Pickens and others from Hollywood. Prior to World War II, Hayward had a high concentration of Japanese Americans, who were subject to the Japanese-American internment during the war; the war brought an economic and population boom to the area, as factories opened to manufacture war material. Many of the workers stayed after the end of the war. Two suburban tract housing pioneers, Oliver Rousseau and David D. Bohannon, were prominent builders of postwar housing in the area; the Hayward Area Recreation and Park District was formed in 1944. California State University, Hayward opened in the Hayward Hills in 1957. Southland Mall was dedicated in 1964; the second San Mateo–Hayward Bridge opened in 1967. The City Center Building opened in 1969 and acted as the new city hall until 1989 when the 1989 Loma Prieta earthquake damaged the building and forced the city government to move out.
The building was closed with the new Hayward City Hall opening the same year. BART began operating in the Bay Area with stations in downtown Hayward and south Hayward; the Hunt Brothers Cannery closed in 1981. The Russell City Energy Center began operating in 2013 at the Hayward shoreline; the city's downtown area was slated for redevelopment in 2012 and 2013, with landscaping, new businesses opening up, a
California Air National Guard
The California Air National Guard is the air force militia of the U. S. State of California, it is, along with the California Army National Guard, an element of the California National Guard. As state militia units, the units in the California Air National Guard are not in the normal United States Air Force chain of command, they are under the jurisdiction of the Governor of California through the office of the California Adjutant General unless they are federalized by order of the President of the United States. The California Air National Guard is headquartered in Sacramento, its commander is Brigadier General Gregory F. Jones. Under the "Total Force" concept, California Air National Guard units are considered to be Air Reserve Components of the United States Air Force. California ANG units are trained and equipped by the Air Force and are operationally gained by a Major Command of the USAF if federalized. In addition, the California Air National Guard forces are assigned to Air Expeditionary Forces and are subject to deployment tasking orders along with their active duty and Air Force Reserve counterparts in their assigned cycle deployment window.
Along with their federal reserve obligations, the California ANG is subject to activation by order of the Governor to provide protection of life and property, preserve peace and public safety. State missions include disaster relief in times of earthquakes, hurricanes and forest fires and rescue, protection of vital public services, support to civil defense. In addition, the California State Military Reserve is an all-volunteer militia force under the California Military Department that provides reserve personnel to both the California Army National Guard and the California Air National Guard, it is under state jurisdiction and its members are employed only within the State of California. It is not subject to be ordered or assigned as any element of the federal armed forces, its mission is to provide units organized and trained in the protection of life or property and the preservation of peace and public safety under competent orders of State authorities. The California Air National Guard consists of the following major units: 129th Rescue WingEstablished 3 April 1955.
Many high-risk lifesaving missions involved long-range, over-water flights, air refueling of helicopters by the HC-130 aircraft, skilled maneuvering by ships and helicopters to recover patients from the decks of these vessels.144th Fighter WingEstablished 2 June 1948. In transition from a KC-135 Stratotanker air refueling mission to an MQ-1 Predator ISR wing, executing global unmanned aerial systems, combat support, humanitarian missions.195th WingEstablished 13 May 1948. The California Air National Guard origins date to 28 August 1917 with the establishment of the 115th Aero Squadron as part of the World War I United States Army Air Service; the 115th served in France on the Western Front, constructed facilities and engaged in supply and related base support activities after the 1918 Armistice with Germany was demobilized in 1919. The Militia Act of 1903 established the present National Guard system, units raised by the states but paid for by the Federal Government, liable for immediate state service.
If federalized by Presidential order, they fall under the regular military chain of command. On 1 June 1920, the Militia Bureau issued Circular No.1 on organization of National Guard air units. The 115th Observation Squadron was established by the Militia Bureau on 5 April 1924, which authorized the immediate organization of the 115th Observation Squadron, 40th Division of Aviation, California National Guard; the Unit held its meetings at Clover Field, Santa Monica, using Reserve Equipment planes for flying. On, the Squadron met at the National Guard Armory and at the University of Southern California. In 1925, several months after its organization, the Squadron moved to permanent quarters at Griffith Park Aerodrome in Los Angeles; the 115th Observation Squadron was ordered into active United States Army Air Corps service on 3 March 1941 as part of the buildup of the Army Air Corps prior to the United States entry into World War II. On 24 May 1946, the United States Army Air Forces, in response to dramatic postwar military budget cuts, imposed by President Harry S. Truman, allocat
Grumman HU-16 Albatross
The Grumman HU-16 Albatross is a large twin–radial engine amphibious flying boat, used by the United States Air Force, the U. S. Navy and the U. S. Coast Guard as a search and rescue aircraft. Designated as the SA-16 for the USAF and the JR2F-1 and UF-1 for the USN and USCG, it was redesignated as the HU-16 in 1962. An improvement of the design of the Grumman Mallard, the Albatross was developed to land in open ocean situations to accomplish rescues, its deep-V hull cross-section and keel length enable it to land in the open sea. The Albatross was designed for optimal 4-foot seas, could land in more severe conditions, but required JATO for takeoff in 8–10-foot seas or greater; the majority of Albatrosses were used by the U. S. Air Force in the search and rescue mission role, designated as SA-16; the USAF used the SA-16 extensively in Korea for combat rescue, where it gained a reputation as a rugged and seaworthy craft. The redesignated HU-16B Albatross was used by the USAF's Aerospace Rescue and Recovery Service and saw extensive combat service during the Vietnam War.
In addition a small number of Air National Guard air commando groups were equipped with HU-16s for covert infiltration and extraction of special forces from 1956 to 1971. Other examples of the HU-16 made their way into Air Force Reserve air rescue units prior to its retirement from USAF service; the U. S. Navy employed the HU-16C/D Albatross as an SAR aircraft from coastal naval air stations, both stateside and overseas, it was employed as an operational support aircraft worldwide and for missions from the former NAS Agana, Guam during the Vietnam War. Goodwill flights were common to the surrounding Trust Territory of the Pacific Islands in the early 1970s. Open water landings and water takeoff training using JATO was conducted by U. S. Navy HU-16s from locations such as Guam; the HU-16 was operated by the U. S. Coast Guard as both a coastal and long-range open ocean SAR aircraft for many years until it was supplanted by the HU-25 Guardian and HC-130 Hercules; the final USAF HU-16 flight was the delivery of AF Serial No.
51-5282 to the National Museum of the United States Air Force at Wright-Patterson AFB, Ohio in July 1973 after setting an altitude record of 32,883 ft earlier in the month. The final US Navy HU-16 flight was made 13 August 1976 when an Albatross was delivered to the National Museum of Naval Aviation at NAS Pensacola, Florida; the final USCG HU-16 flight was at CGAS Cape Cod in March 1983, when the aircraft type was retired by the USCG. The Albatross continued to be used in the military service of other countries, the last being retired by the Hellenic Navy in 1995; the Royal Canadian Air Force operated Grumman Albatrosses with the designation "CSR-110". In the mid-1960s the U. S. Department of the Interior acquired 3 military Grumman HU-16's from the U. S. Navy and established the Trust Territory Airlines in the Pacific to serve the islands of Micronesia. Pan American World Airways and Continental Airlines' Air Micronesia operated the Albatrosses serving Yap, Palau and Pohnpei from Guam until 1970, when adequate island runways were built, allowing land operations.
In 1970, Conroy Aircraft marketed a remanufactured HU-16A with Rolls-Royce Dart turboprop engines as the Conroy Turbo Albatross, but only one prototype was built. Many surplus Albatrosses were sold to civilian operators to private owners; these aircraft are operated under either Experimental-Exhibition or Restricted category and cannot be used for commercial operations, except under limited conditions. In the early 1980s Chalk's International Airlines owned by Merv Griffin's Resorts International had 13 Albatrosses converted to Standard category as G-111s; this made them eligible to be used in scheduled airline operations. These aircraft had extensive modification from the standard military configuration, including rebuilt wings with titanium wing spar caps, additional doors and modifications to existing doors and hatches, stainless steel engine oil tanks, dual engine fire extinguishing systems on each engine and propeller auto feather systems installed; the G-111s were operated for only a few years and put in storage in Arizona.
Most are still parked there, but some have been returned to regular flight operations with private operators. Satellite technology company Row 44 uses an HU-16B Albatross to test its in-flight satellite broadband internet service. Purchased and named Albatross One in 2008, the company selected this aircraft for its operations because it has the same curvature atop its fuselage as the Boeing 737 aircraft for which the company manufactures its equipment; the plane purchased by Row 44 was used at one time as a training aircraft for space shuttle astronauts by NASA. It features the autographs of the astronauts. In 1997 a Grumman Albatross, piloted by Reid Dennis and Andy Macfie, became the first Albatross to circumnavigate the globe; the 26,347 nmi flight around the world lasted 73 days, included 38 stops in 21 countries, was completed with 190 hours of flight time. In 2013 Reid Dennis donated N44RD to the Hiller Aviation Museum. Since the aircraft weighs over 12,500 pounds, pilots of civilian US-registered Albatross aircraft must have a type rating.
There is a yearly Albatross fly-in at Boulder City, Nevada where Albatross pilots can become
San Francisco Bay
San Francisco Bay is a shallow estuary in the US state of California. It is surrounded by a contiguous region known as the San Francisco Bay Area, is dominated by the large cities of San Jose, San Francisco and Oakland. San Francisco Bay drains water from 40 percent of California. Water from the Sacramento and San Joaquin rivers, from the Sierra Nevada mountains, flow into Suisun Bay, which travels through the Carquinez Strait to meet with the Napa River at the entrance to San Pablo Bay, which connects at its south end to San Francisco Bay; the Guadalupe River enters the bay at its southernmost point in San Jose. The Guadalupe drains water from the Santa Cruz mountains and Hamilton Mountain ranges in southernmost San Jose, it enters the bay at the town of Alviso. It connects to the Pacific Ocean via the Golden Gate strait. However, this entire group of interconnected bays is called the San Francisco Bay; the bay was designated a Ramsar Wetland of International Importance on February 2, 2012. The bay covers somewhere between 400 and 1,600 square miles, depending on which sub-bays, wetlands, so on are included in the measurement.
The main part of the bay measures three to twelve miles wide east-to-west and somewhere between 48 miles 1 and 60 miles 2 north-to-south. It is the largest Pacific estuary in the Americas; the bay was navigable as far south as San Jose until the 1850s, when hydraulic mining released massive amounts of sediment from the rivers that settled in those parts of the bay that had little or no current. Wetlands and inlets were deliberately filled in, reducing the Bay's size since the mid-19th century by as much as one third. Large areas of wetlands have been restored, further confusing the issue of the Bay's size. Despite its value as a waterway and harbor, many thousands of acres of marshy wetlands at the edges of the bay were, for many years, considered wasted space; as a result, soil excavated for building projects or dredged from channels was dumped onto the wetlands and other parts of the bay as landfill. From the mid-19th century through the late 20th century, more than a third of the original bay was filled and built on.
The deep, damp soil in these areas is subject to soil liquefaction during earthquakes, most of the major damage close to the Bay in the Loma Prieta earthquake of 1989 occurred to structures on these areas. The Marina District of San Francisco, hard hit by the 1989 earthquake, was built on fill, placed there for the Panama-Pacific International Exposition, although liquefaction did not occur on a large scale. In the 1990s, San Francisco International Airport proposed filling in hundreds more acres to extend its overcrowded international runways in exchange for purchasing other parts of the bay and converting them back to wetlands; the idea was, remains, controversial. There are five large islands in San Francisco Bay. Alameda, the largest island, was created when a shipping lane was cut to form the Port of Oakland in 1901, it is now a suburban community. Angel Island was known as "Ellis Island West" because it served as the entry point for immigrants from East Asia, it is now a state park accessible by ferry.
Mountainous Yerba Buena Island is pierced by a tunnel linking the east and west spans of the San Francisco–Oakland Bay Bridge. Attached to the north is the artificial and flat Treasure Island, site of the 1939 Golden Gate International Exposition. From the Second World War until the 1990s, both islands served as military bases and are now being redeveloped. Isolated in the center of the Bay is Alcatraz, the site of the famous federal penitentiary; the federal prison on Alcatraz Island no longer functions, but the complex is a popular tourist site. Despite its name, Mare Island in the northern part of the bay is a peninsula rather than an island. San Francisco Bay is thought to represent a down-warping of the Earth's crust between the San Andreas Fault to the west and the Hayward Fault to the east, though the precise nature of this remains under study. About 560,000 years ago, a tectonic shift caused the large inland Lake Corcoran to spill out the central valley and through the Carquinez Strait, carving out sediment and forming canyons in what is now the northern part of the San Francisco Bay and Golden Gate strait.
Until the last ice age, the basin, now filled by the San Francisco Bay was a large linear valley with small hills, similar to most of the valleys of the Coast Ranges. As the great ice sheets began to melt, around 11,000 years ago, the sea level started to rise. By 5000 BC the sea level rose 300 feet; the valley become a bay, the small hills became islands. From 15,000 – 10,000 years ago, the Ohlone tribe inhabited the area, now the San Francisco Bay; the natives were displaced 5,000 years ago as the bay filled with water due to the rising sea level at the end of the ice age. The first European to see San Francisco Bay is N. de Morena, left at New Albion at Drakes Bay in Marin County, California by Sir Francis Drake in 1579 and walked to Mexico. The first recorded European discovery of San Francisco Bay was on November 4, 1769 when Spanish explorer Gaspar de Portolà, unable to find the port of Monterey, continued north close to what is now Pacifica and reached the summit of the 1,200-foot-high Sweeney Ridge, now marked as the place where he first sighted San Francisco Bay.
Portolá and his party did not realize what they had discovered, thinking they had arrived at a large arm of what is now called Drakes Bay. At the time, Drakes Bay went by the name Bahia de San
An orthophoto, orthophotograph or orthoimage is an aerial photograph or satellite imagery geometrically corrected such that the scale is uniform: the photo or image has follows a given map projection. Unlike an uncorrected aerial photograph, an orthophoto can be used to measure true distances, because it is an accurate representation of the Earth's surface, having been adjusted for topographic relief, lens distortion, camera tilt. Orthophotographs are used in geographic information systems as a "map accurate" background image. An orthorectified image differs from "rubber sheeted" rectifications as the latter may locate a number of points on each image but "stretch" the area between so scale may not be uniform across the image. A digital elevation model is required to create an accurate orthophoto as distortions in the image due to the varying distance between the camera/sensor and different points on the ground need to be corrected. An orthoimage and a "rubber sheeted" image can both be said to have been "georeferenced" however the overall accuracy of the rectification varies.
Software can display the orthophoto and allow an operator to digitize or place linework, text annotations or geographic symbols. Some software can produce the linework automatically. Production of orthophotos was achieved using mechanical devices. An orthophotomosaic is a raster image made by merging orthophotos — aerial or satellite photographs which have been transformed to correct for perspective so that they appear to have been taken from vertically above at an infinite distance. Google Earth images are of this type; the document representing an orthophotomosaic with additional marginal information like a title, north arrow, scale bar and cartographical information is called an orthophotomap or image map. These maps show additional point, line or polygon layers on top of the orthophotomosaic. A similar document used for disaster relief, is called a spatiomap. Aerial Photography Digital Orthophoto Quadrangle and Digital Orthophoto Quarter Quadrangle Leica Photogrammetry Suite Orthorectification Software GRASS GIS Photogrammetry Photomapping TopoFlight Socet set Orthophoto Software U.
S. Geological Survey Rational Polynomial Coefficient Bolstad, P. GIS Fundamentals: A First Text on Geographic Information Systems, Eider Press, White Bear Lake, MN, 2nd ed. Demers, Michael N.. Fundamentals of Geographic Information Systems, John Wiley & Sons. Fernandez, E. Garfinkel, R. & Roman Arbiol. "Mosaicking of Aerial Photographic Maps Via Seams Defined by Bottleneck Shortest Paths". Operations Research. 46: 293–304. Doi:10.1287/opre.46.3.293. CS1 maint: Uses authors parameter. Petrie, G. Transactions of the Institute of British Geographers: Orthophotomaps New Series, vol. 2, no.1, Contemporary Cartography. Pg. 49-70 Robinson, A. H. Morrison, J. L. Muehrcke, P. C. Kimerling, A. J. Stephen Guptill, Elements of Cartography: John Wiley & Sons Inc. Canada, 6th ed. United States Geological Survey, US Department of Interior, USGS Fact Sheet May 2001 http://erg.usgs.gov/isb/pubs/factsheets/fs05701.html United States Geological Survey National Digital Orthophoto Programs - Original Site via Wayback Machine National Digital Orthoimagery Program National Digital Orthoimagery Program Subcommittee
According to the International Civil Aviation Organization, a runway is a "defined rectangular area on a land aerodrome prepared for the landing and takeoff of aircraft". Runways may be a natural surface. In January 1919, aviation pioneer Orville Wright underlined the need for "distinctly marked and prepared landing places, the preparing of the surface of reasonably flat ground an expensive undertaking there would be a continuous expense for the upkeep." Runways are named by a number between 01 and 36, the magnetic azimuth of the runway's heading in decadegrees. This heading differs from true north by the local magnetic declination. A runway numbered 09 points east, runway 18 is south, runway 27 points west and runway 36 points to the north; when taking off from or landing on runway 09, a plane is heading around 90°. A runway can be used in both directions, is named for each direction separately: e.g. "runway 15" in one direction is "runway 33" when used in the other. The two numbers differ by 18.
For clarity in radio communications, each digit in the runway name is pronounced individually: runway one-five, runway three-three, etc.. A leading zero, for example in "runway zero-six" or "runway zero-one-left", is included for all ICAO and some U. S. military airports. However, most U. S. civil aviation airports drop the leading zero. This includes some military airfields such as Cairns Army Airfield; this American anomaly may lead to inconsistencies in conversations between American pilots and controllers in other countries. It is common in a country such as Canada for a controller to clear an incoming American aircraft to, for example, runway 04, the pilot read back the clearance as runway 4. In flight simulation programs those of American origin might apply U. S. usage to airports around the world. For example, runway 05 at Halifax will appear on the program as the single digit 5 rather than 05. If there is more than one runway pointing in the same direction, each runway is identified by appending left and right to the number to identify its position — for example, runways one-five-left, one-five-center, one-five-right.
Runway zero-three-left becomes runway two-one-right. In some countries, regulations mandate that where parallel runways are too close to each other, only one may be used at a time under certain conditions. At large airports with four or more parallel runways some runway identifiers are shifted by 1 to avoid the ambiguity that would result with more than three parallel runways. For example, in Los Angeles, this system results in runways 6L, 6R, 7L, 7R though all four runways are parallel at 69°. At Dallas/Fort Worth International Airport, there are five parallel runways, named 17L, 17C, 17R, 18L, 18R, all oriented at a heading of 175.4°. An airport with only three parallel runways may use different runway identifiers, such as when a third parallel runway was opened at Phoenix Sky Harbor International Airport in 2000 to the south of existing 8R/26L — rather than confusingly becoming the "new" 8R/26L it was instead designated 7R/25L, with the former 8R/26L becoming 7L/25R and 8L/26R becoming 8/26.
Runway designations may change over time because Earth's magnetic lines drift on the surface and the magnetic direction changes. Depending on the airport location and how much drift occurs, it may be necessary to change the runway designation; as runways are designated with headings rounded to the nearest 10°, this affects some runways sooner than others. For example, if the magnetic heading of a runway is 233°, it is designated Runway 23. If the magnetic heading changes downwards by 5 degrees to 228°, the runway remains Runway 23. If on the other hand the original magnetic heading was 226°, the heading decreased by only 2 degrees to 224°, the runway becomes Runway 22; because magnetic drift itself is slow, runway designation changes are uncommon, not welcomed, as they require an accompanying change in aeronautical charts and descriptive documents. When runway designations do change at major airports, it is changed at night as taxiway signs need to be changed and the huge numbers at each end of the runway need to be repainted to the new runway designators.
In July 2009 for example, London Stansted Airport in the United Kingdom changed its runway designations from 05/23 to 04/22 during the night. For fixed-wing aircraft it is advantageous to perform takeoffs and landings into the wind to reduce takeoff or landing roll and reduce the ground speed needed to attain flying speed. Larger airports have several runways in different directions, so that one can be selected, most nearly aligned with the wind. Airports with one runway are constructed to be aligned with the prevailing wind. Compiling a wind rose is in fact one of the preliminary steps taken in constructing airport runways. Note that wind direction is given as the direction the wind is coming from: a plane taking off from runway 09 faces east, into an "east wind" blowing from 090°. Runway dimensions vary from as small as 245 m long and 8 m wide in s