Minneapolis–Saint Paul International Airport
Minneapolis–Saint Paul International Airport less known as Wold–Chamberlain Field, is a joint civil-military public use international airport. It is located in a portion of Hennepin County, United States, within 10 miles of both downtown Minneapolis and Saint Paul. MSP is the largest and busiest airport in the six-state Upper Midwest region of Minnesota, Nebraska, North Dakota, South Dakota, Wisconsin. A joint civil-military airport, MSP is home to the Minneapolis–Saint Paul International Airport Joint Air Reserve Station, supporting both Air Force Reserve Command and Air National Guard flight operations; the airport is located in the census-designated place of Fort Snelling in an unincorporated portion of Hennepin County. Small sections of the airport are within the city limits of Richfield. However, per Minnesota state law, the land on which the airport sits is not part of any city or school district. In 2017, Minneapolis–Saint Paul International Airport was the 17th busiest airport in the United States.
The airport was named best Airport in North America among air terminals that serve 25 to 40 million passengers annually, the second largest category, in 2016, 2017 and 2018 by The Airports Council International. The airport generates an estimated $15.9 billion a year for the Twin Cities' economy and supports 87,000 workers. MSP is the third largest hub airport for Delta Air Lines and its Delta Connection partners by passenger traffic, it serves as the home airport for Minnesota-based Sun Country Airlines. Delta Air Lines and its regional affiliates account for about 70% of the airport's passenger traffic; the airport is operated by the Metropolitan Airports Commission, which handles the operation of six smaller airports in the region. The airport came into being when several local groups came together to take control of the former bankrupt Twin City Speedway race track, giving the airport its original name, Speedway Field. Soon after, in 1921, the airport was renamed "Wold–Chamberlain Field" for the World War I pilots Ernest Groves Wold and Cyrus Foss Chamberlain.
Howard Hughes stopped at Wold–Chamberlain Field on his round the world flight in 1938. In 1944 the site was renamed to "Minneapolis–St. Paul Metropolitan Airport/Wold-Chamberlain Field", with "International" replacing "Metropolitan" four years later. Today it is rare to see the Wold–Chamberlain portion of the name used anywhere. MSP was the main base for Northwest Airlines starting in 1926 and became the main base of regional carrier North Central Airlines in 1952. North Central merged with Southern Airways to form Republic Airlines in 1979; the combined carrier came to control 79% of traffic at the airport, merged into Delta Air Lines in 2010. Ground was broken for the current Charles Lindbergh terminal building on October 26, 1958; the US $8.5 million, 600,000 square foot terminal with 24 gates on two concourses was designed by Lyle George Landstrom who worked for Cerny Associates and completed on January 13, 1962 and operations began on January 21, 1962. Pier D was completed in 1971 and Pier A was completed in 1972 as part of an expansion of the terminal designed by Cerny Associates.
This project involved rebuilding the existing concourses into bi-level structures equipped with holding rooms and jet bridges. It handles airlines such as Delta and others; the Gold Concourse included the airport's first moving walkway. In 1970, MSP served as the primary filming location for the film Airport, though the film presented the airport as a fictional Chicago-based Lincoln International. MSP was selected in part for notorious winter climate, yet the filming period remained stubbornly fair-weathered, forcing film crews to employ copious amounts of fake snow; as filming had to take place during normal airport operations, several features of the airport itself, such as the color-based labeling of different concourses, were present in the movie. This labeling system was replaced beginning in 2000 with the more familiar system of lettered concourses. Due in part to the impact of aircraft noise on south Minneapolis and surrounding suburbs, proposals were made in the 1990s to build a new airport on the fringes of the Twin Cities metro in Dakota County to handle larger jets and more international traffic.
Minneapolis and other neighboring cities were concerned that such a move would have a negative economic impact, so an arrangement was made where the Metropolitan Airports Commission would outfit many homes in the vicinity of the airport with sound insulation and air conditioning so that indoor noise could be reduced. A citizen group named ROAR was helped push the MAC to make these concessions. In 2004, the MAC voted to reduce funding for the soundproofing projects, stating in part that the economic climate had turned in the wake of the September 11 attacks. Minneapolis Mayor R. T. Rybak, a founding member of ROAR, promised that the city would challenge the funding changes; the Hubert H. Humphrey Terminal was built in 2001, it is used for charter and low cost airlines, including Minnesota-based Sun Country and Southwest, but is used for Condor and JetBlue. The terminal has a total of 14 gates. Concourses A and B opened on June 1, 2002 as part of a $250 million terminal expansion designed by Minneapolis-based Architectural Alliance.
The final component of the project included a $17.5 million extension of Concourse C consisting of six additional gates, which opened on October 31, 2
Phoenix–Mesa Gateway Airport
Phoenix–Mesa Gateway Airport Williams Gateway Airport and Williams Air Force Base, is an international airport in the southeastern area of Mesa, 20 miles southeast of Phoenix, in Maricopa County, Arizona. The airport is owned and operated by the Phoenix–Mesa Gateway Airport Authority, is a reliever airport for Phoenix Sky Harbor International Airport, it is a base for Allegiant Air. The airport authority is governed by a six-member board: the mayors of the towns of Gilbert and Queen Creek, the mayors of the cities of Mesa and Apache Junction, the tribal governor of the Gila River Indian Community; the FAA's National Plan of Integrated Airport Systems for 2007–2011 called Phoenix–Mesa Gateway a reliever airport, a general aviation airport used to relieve congestion at a large airline airport. Allegiant Air began scheduled service from Mesa in October 2007. Phoenix Mesa Gateway Airport records say the airport had 1,338,216 passenger boardings in calendar year 2017. Most U. S. airports use the same three-letter location identifier for the FAA and IATA, but Phoenix–Mesa Gateway Airport has different codes for each.
The aviation community uses the FAA code of IWA, while commercial passenger flight organizations use the IATA code of AZA. The airport was built in 1941 as Higley Field. In 1948 the field was acquired by the United States military and renamed as Williams Air Base in January 1948, it was a flight training field during World War II. In 1948 Williams became the first jet training base, in 1966 it was the first site of the Undergraduate Pilot Training program; the 1991 Base Realignment and Closure Commission recommended closing the base as its operating costs were too high. As the base was being shut down, it was decided that, with the growing traffic at Sky Harbor International Airport in Phoenix, an alternative airport would be needed; the runway was expanded to accommodate airliners and the facility opened in 1994 as Williams Gateway Airport. Bids began for some airlines to begin flights immediately. In 2004 charter airline Ryan International Airlines began MD-82 flights to Bullhead City International Airport in Bullhead City, next to Laughlin and many resorts.
In recent years, the airport has again become a center of flight training. Several large flight schools now take advantage of the flying weather in the Phoenix valley. On July 31, 2007 the low-cost Las Vegas-based carrier Allegiant Air announced plans to open a focus city at Phoenix–Mesa Gateway Airport, connecting the Phoenix area to 13 cities. Service commenced on October 25, 2007, with cities being added until November 21, 2007. In a press release on September 17, 2007, the Williams Gateway Airport Authority governing board approved a name change for Williams Gateway Airport effective October 15, 2007 to Phoenix–Mesa Gateway Airport. On June 16, 2015, after Elite Airways announced non-stop flights from San Diego and Salt Lake City to Phoenix–Mesa, Allegiant threatened to leave the airport; this is due to the incentives the airport is offering to Elite. If Allegiant were to leave, it would consider relocating to the nearby Phoenix Sky Harbor International Airport. On January 21, 2017, Phoenix-Mesa welcomed its first international flight and first two international destinations, as Westjet inaugurated its seasonal service to Calgary and Edmonton, Alberta.
Westjet has seen success at Phoenix Sky Harbor for years, with Calgary and Edmonton being the 1st and 6th most popular international destinations at Sky Harbor, respectively. In 1994, the Willams Gateway Airport Authority was established with a three-member board with representation from the three cities adjacent to Williams Field; the original governing board consisted of the mayors of the towns of Gilbert and Queen Creek and the city of Mesa, who continue as members today. In years, the Gila River Indian Community and the city of Phoenix joined the Williams Gateway Airport Authority board. Gila River Indian Community joined in 1995 and the City of Phoenix joined in 2006; the city of Apache Junction joined in 2013. Now that the change of the Williams Gateway Airport name to Phoenix–Mesa Gateway Airport has occurred, the board approved resolution and ordinance does not change, give away, nor reduce any of the board of directors and their respective city, town, or tribal government member voting authority and respective ownership.
Phoenix–Mesa Gateway Airport continues to be owned and operated by the Phoenix Mesa Gateway Airport Authority. A six-member airport Board of Directors is composed of elected officials from neighboring cities and a tribal government. Authority communities are: Apache Junction Gilbert Gila River Indian Community Mesa Phoenix Queen Creek The airport covers 3,020 acres and has three paved runways: Runway 12C/30C: 10,201 ft × 150 ft Asphalt/Concrete Runway 12L/30R: 9,300 ft × 150 ft Concrete Runway 12R/30L: 10,401 ft × 150 ft ConcreteIn the year ending December 31, 2017 the airport had 290,452 aircraft operations, an average of 796 per day: 80% general aviation, 13% air taxi, 4% airline and 3% military. In 2017, there were 138 aircraft based at this airport: 88 single-engine, 21 multi-engine and 29 jet. Air Evac Fighter Combat International Advanced Training Sy
Federal Aviation Administration
The Federal Aviation Administration is a governmental body of the United States with powers to regulate all aspects of civil aviation in that nation as well as over its surrounding international waters. Its powers include the construction and operation of airports, air traffic management, the certification of personnel and aircraft, the protection of U. S. assets during the launch or re-entry of commercial space vehicles. Powers over neighboring international waters were delegated to the FAA by authority of the International Civil Aviation Organization. Created in August 1958, the FAA replaced the former Civil Aeronautics Administration and became an agency within the US Department of Transportation; the FAA's roles include: Regulating U. S. commercial space transportation Regulating air navigation facilities' geometric and flight inspection standards Encouraging and developing civil aeronautics, including new aviation technology Issuing, suspending, or revoking pilot certificates Regulating civil aviation to promote transportation safety in the United States through local offices called Flight Standards District Offices Developing and operating a system of air traffic control and navigation for both civil and military aircraft Researching and developing the National Airspace System and civil aeronautics Developing and carrying out programs to control aircraft noise and other environmental effects of civil aviation The FAA is divided into four "lines of business".
Each LOB has a specific role within the FAA. Airports: plans and develops projects involving airports, overseeing their construction and operations. Ensures compliance with federal regulations. Air Traffic Organization: primary duty is to safely and efficiently move air traffic within the National Airspace System. ATO employees manage air traffic facilities including Airport Traffic Control Towers and Terminal Radar Approach Control Facilities. See Airway Operational Support. Aviation Safety: Responsible for aeronautical certification of personnel and aircraft, including pilots and mechanics. Commercial Space Transportation: ensures protection of U. S. assets during the launch or reentry of commercial space vehicles. The FAA is headquartered in Washington, D. C. as well as the William J. Hughes Technical Center in Atlantic City, New Jersey, the Mike Monroney Aeronautical Center in Oklahoma City and its nine regional offices: Alaskan Region – Anchorage, Alaska Northwest Mountain – Seattle, Washington Western Pacific – Los Angeles, California Southwest – Fort Worth, Texas Central – Kansas City, Missouri Great Lakes – Chicago, Illinois Southern – Atlanta, Georgia Eastern – New York, New York New England – Boston, Massachusetts The Air Commerce Act of May 20, 1926, is the cornerstone of the federal government's regulation of civil aviation.
This landmark legislation was passed at the urging of the aviation industry, whose leaders believed the airplane could not reach its full commercial potential without federal action to improve and maintain safety standards. The Act charged the Secretary of Commerce with fostering air commerce and enforcing air traffic rules, licensing pilots, certifying aircraft, establishing airways, operating and maintaining aids to air navigation; the newly created Aeronautics Branch, operating under the Department of Commerce assumed primary responsibility for aviation oversight. In fulfilling its civil aviation responsibilities, the Department of Commerce concentrated on such functions as safety regulations and the certification of pilots and aircraft, it took over the building and operation of the nation's system of lighted airways, a task initiated by the Post Office Department. The Department of Commerce improved aeronautical radio communications—before the founding of the Federal Communications Commission in 1934, which handles most such matters today—and introduced radio beacons as an effective aid to air navigation.
The Aeronautics Branch was renamed the Bureau of Air Commerce in 1934 to reflect its enhanced status within the Department. As commercial flying increased, the Bureau encouraged a group of airlines to establish the first three centers for providing air traffic control along the airways. In 1936, the Bureau itself began to expand the ATC system; the pioneer air traffic controllers used maps and mental calculations to ensure the safe separation of aircraft traveling along designated routes between cities. In 1938, the Civil Aeronautics Act transferred the federal civil aviation responsibilities from the Commerce Department to a new independent agency, the Civil Aeronautics Authority; the legislation expanded the government's role by giving the CAA the authority and the power to regulate airline fares and to determine the routes that air carriers would serve. President Franklin D. Roosevelt split the authority into two agencies in 1940: the Civil Aeronautics Administration and the Civil Aeronautics Board.
CAA was responsible for ATC, airman and aircraft certification, safety enforcement, airway development. CAB was entrusted with safety regulation, accident investigation, economic regulation of the airlines; the CAA was part of the Department of Commerce. The CAB was an independent federal agency. On the eve of America's entry into World War II, CAA began to extend its ATC responsibilities to takeoff and landing operations at airports; this expanded role became permanent after the war. The application of radar to ATC helped controllers in their drive to keep abreast of the postwar boom in commercial air transportation. In 1946, Congress gave CAA the added task of administering the federal-aid airport program, the first peacetime program of financial assistance aimed exclusivel
The elevation of a geographic location is its height above or below a fixed reference point, most a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational surface. The term elevation is used when referring to points on the Earth's surface, while altitude or geopotential height is used for points above the surface, such as an aircraft in flight or a spacecraft in orbit, depth is used for points below the surface. Elevation is not to be confused with the distance from the center of the Earth. Due to the equatorial bulge, the summits of Mount Everest and Chimborazo have the largest elevation and the largest geocentric distance. GIS or geographic information system is a computer system that allows for visualizing, manipulating and storage of data with associated attributes. GIS offers better understanding of relationships of the landscape at different scales. Tools inside the GIS allow for manipulation of data for spatial cartography. A topographical map is the main type of map used to depict elevation through use of contour lines.
In a Geographic Information System, digital elevation models are used to represent the surface of a place, through a raster dataset of elevations. Digital terrain models are another way to represent terrain in GIS. USGS is developing a 3D Elevation Program to keep up with growing needs for high quality topographic data. 3DEP is a collection of enhanced elevation data in the form of high quality LiDAR data over the conterminous United States and the U. S. territories. There are three bare earth DEM layers in 3DEP which are nationally seamless at the resolution of 1/3, 1, 2 arcseconds; this map is derived from GTOPO30 data that describes the elevation of Earth's terrain at intervals of 30 arcseconds. It uses shading instead of contour lines to indicate elevation. Height Orthometric height Hypsography Geodesy Geodesy of North America Sea Level Datum of 1929 National Geodetic Vertical Datum of 1929 North American Vertical Datum of 1988 List of European cities by elevation List of highest mountains List of highest towns by country Normaal Amsterdams Peil Normalhöhennull Physical geography Table of the highest major summits of North America Temperature lapse rate Topographic isolation Topographic prominence Topography Vertical pressure variation U.
S. National Geodetic Survey website Geodetic Glossary @ NGS NGVD 29 to NAVD 88 online elevation converter @ NGS United States Geological Survey website Geographical Survey Institute Downloadable ETOPO2 Raw Data Database Downloadable ETOPO5 Raw Data Database Find the elevation of any place
The hectare is an SI accepted metric system unit of area equal to a square with 100-metre sides, or 10,000 m2, is used in the measurement of land. There are 100 hectares in one square kilometre. An acre is about 0.405 hectare and one hectare contains about 2.47 acres. In 1795, when the metric system was introduced, the "are" was defined as 100 square metres and the hectare was thus 100 "ares" or 1⁄100 km2; when the metric system was further rationalised in 1960, resulting in the International System of Units, the are was not included as a recognised unit. The hectare, remains as a non-SI unit accepted for use with the SI units, mentioned in Section 4.1 of the SI Brochure as a unit whose use is "expected to continue indefinitely". The name was coined from the Latin ārea; the metric system of measurement was first given a legal basis in 1795 by the French Revolutionary government. The law of 18 Germinal, Year III defined five units of measure: The metre for length The are for area The stère for volume of stacked firewood The litre for volumes of liquid The gram for massIn 1960, when the metric system was updated as the International System of Units, the are did not receive international recognition.
The International Committee for Weights and Measures makes no mention of the are in the current definition of the SI, but classifies the hectare as a "Non-SI unit accepted for use with the International System of Units". In 1972, the European Economic Community passed directive 71/354/EEC, which catalogued the units of measure that might be used within the Community; the units that were catalogued replicated the recommendations of the CGPM, supplemented by a few other units including the are whose use was limited to the measurement of land. The names centiare, deciare and hectare are derived by adding the standard metric prefixes to the original base unit of area, the are; the centiare is one square metre. The deciare is ten square metres; the are is a unit of area, used for measuring land area. It was defined by older forms of the metric system, but is now outside the modern International System of Units, it is still used in colloquial speech to measure real estate, in particular in Indonesia, in various European countries.
In Russian and other languages of the former Soviet Union, the are is called sotka. It is used to describe the size of suburban dacha or allotment garden plots or small city parks where the hectare would be too large; the decare is derived from deca and are, is equal to 10 ares or 1000 square metres. It is used in Norway and in the former Ottoman areas of the Middle East and the Balkans as a measure of land area. Instead of the name "decare", the names of traditional land measures are used, redefined as one decare: Stremma in Greece Dunam, donum, or dönüm in Israel, Jordan, Lebanon and Turkey Mål is sometimes used for decare in Norway, from the old measure of about the same area; the hectare, although not a unit of SI, is the only named unit of area, accepted for use within the SI. In practice the hectare is derived from the SI, being equivalent to a square hectometre, it is used throughout the world for the measurement of large areas of land, it is the legal unit of measure in domains concerned with land ownership and management, including law, agriculture and town planning throughout the European Union.
The United Kingdom, United States, to some extent Canada use the acre instead. Some countries that underwent a general conversion from traditional measurements to metric measurements required a resurvey when units of measure in legal descriptions relating to land were converted to metric units. Others, such as South Africa, published conversion factors which were to be used "when preparing consolidation diagrams by compilation". In many countries, metrication clarified existing measures in terms of metric units; the following legacy units of area have been redefined as being equal to one hectare: Jerib in Iran Djerib in Turkey Gong Qing in Hong Kong / mainland China Manzana in Argentina Bunder in The Netherlands The most used units are in bold. One hectare is equivalent to: 1 square hectometre 15 mǔ or 0.15 qǐng 10 dunam or dönüm 10 stremmata 6.25 rai ≈ 1.008 chō ≈ 2.381 feddan Conversion of units Hecto- Hectometre Order of magnitude Official SI website: Table 6. Non-SI units accepted for use with the International System of Units
McCarran International Airport
McCarran International Airport is the primary commercial airport serving the Las Vegas Valley, a major metropolitan area in the U. S. state of Nevada. It is in Paradise, about 5 miles south of Downtown Las Vegas; the airport is operated by the Clark County Department of Aviation. It is named after the late U. S. Senator Pat McCarran, a member of the Democratic Party who contributed to the development of aviation both in Las Vegas and on a national scale. LAS covers 2,800 acres of land; the airport was built in 1942 and opened to commercial flights in 1948. It has undergone significant expansion since and has employed various innovative technologies, such as common-use facilities; the airport consists of four runways and two passenger terminals: Terminal 1 and Terminal 3. Terminal 1 is composed of four concourses, namely the A, B, C, D Gates. A people mover system is in place between the post-security area of Terminal 1 and the C and D Gates, as well as between the D Gates and Terminal 3. East of the passenger terminals is the Marnell Air Cargo Center, on the west side of the airports are facilities for fixed-base operators and helicopter companies.
McCarran received over 45,300,000 passengers in 2015, a 5.8% increase over the previous year but still below pre-recession levels. It is the 30th busiest airport in the world by passenger traffic and the 8th busiest by aircraft movements; the airport has nonstop air service to destinations in North America and Asia. It is an operating base for Allegiant Air, as well as a crew and maintenance base for Frontier Airlines, Southwest Airlines, Spirit Airlines. Prior to McCarran Airport, the first airport to serve Las Vegas was Anderson Field, opened in November 1920 southeast of present-day Sahara Ave and Paradise Rd. Purchased by the Rockwell brothers in 1925, the airfield was renamed Rockwell Field, Western Air Express introduced commercial air service in April 1926; when the brothers sold Rockwell Field and the new owner canceled WAE's lease, the airline had to look for another airport. Local businessman P. A. Simon had built an airfield northeast of the city, now known as Nellis Air Force Base, to which WAE relocated in November 1929.
Despite rising traffic to Las Vegas, WAE reduced service to the city amid the Great Depression. Once its financial situation improved, the airline bought the airfield and established a monopoly on flights; when the city attempted to purchase the field and build a more modern terminal, WAE refused. With the advent of World War II, however, WAE was pressured to sell the airfield. Nevada Senator Pat McCarran helped obtain federal funding for the city to buy the field and construct a new terminal, he helped establish a gunnery school by the United States Army Air Corps at the field. For the senator's contributions, the airport was named McCarran Field in 1941. A third airfield, Alamo Field, was established in 1942 by aviator George Crockett south of the city of Las Vegas, at the present location of McCarran Airport; as the Army sought to open a local base at the site of McCarran Field, Clark County purchased Alamo Field from Crockett in order to relocate commercial air traffic. Alamo Field became the new McCarran Field on December 19, 1948.
The opening of this new airfield broke Western Air Express' monopoly on flights to Las Vegas, allowing other airlines to serve the market. Meanwhile, the Army reopened its base at the original McCarran Field in 1949 and named it Nellis Air Force Base in 1950. In its first year of operation, McCarran Field served over 35,000 passengers; as the Las Vegas casino industry grew and air travel became more popular during the 1950s, passenger traffic to the airfield rose with 959,603 passengers transiting through it in 1959. To cope with the increase, airport officials began planning a new passenger terminal. While the original terminal was located on Las Vegas Boulevard, the new terminal was built on Paradise Road; the terminal, whose design was inspired by the TWA Flight Center in New York City, opened on March 15, 1963. The airport was renamed McCarran International Airport in September 1968. Further expansion took place between 1974 with the construction of the A and B gates. Prior to deregulation, the airport had four dominant carriers: United and TWA served both coasts nonstop from Las Vegas, while Western and Hughes Airwest provided service to destinations in the western US.
After the airline industry was deregulated in 1978, the number of airlines serving McCarran doubled from seven to fourteen in only two years. New entrants by 1979 included American and Continental. In response, the county launched an expansion plan named McCarran 2000, detailing expansion projects to be undertaken into the year 2000. Expanded baggage claim facilities, an esplanade, a parking garage were inaugurated in 1985; the C Gates and the first line of the people mover system followed in 1987. Further expansion took place during the 1990s; the Charter/International Terminal renamed Terminal 2, was opened in December 1991 to handle rising international traffic to Las Vegas. An additional, nine-story parking garage and an underground tunnel linking the Las Vegas Beltway to the airport were constructed as well. In June 1998, the southwest and southeast wings of the D Gates were opened. During the late 1990s, the airport focused on attracting foreign airlines. In 1994, Condor Flugdienst began charter flights from Germany, launching scheduled service from Cologne and Frankfurt in 1997.
Northwest Airlines and Japan Airlines introduced flights from Tokyo in 1998, Virgin Atlantic began flying from London–Gatwick in 2000. In 1997, the airport introduced Common Use Terminal Equipment, becoming the first
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