Polar route
Encyclopedia
A polar route refers to an aircraft route across the uninhabited polar ice cap region. The American Federal Aviation Administration
Federal Aviation Administration
The Federal Aviation Administration is the national aviation authority of the United States. An agency of the United States Department of Transportation, it has authority to regulate and oversee all aspects of civil aviation in the U.S...

 defines the North Polar area of operations as the area lying north of 78 deg north latitude , which is entirely north of Alaska and most of Siberia. (Airlines started great-circle flights from Europe to the west coast of North America in the 1950s and called them "Polar Route" flights even when they didn't get north of the Arctic Circle.)

During much of the Cold War
Cold War
The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...

 the Arctic region was a buffer zone between the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

 and North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

; civilian flights from Europe to the Asian Far East were unable to cross the Soviet Union or China and had to use a Middle East route or connect through Alaska across the Arctic region. These Cold War tracks extended from the northern Alaskan coast across Greenland to Europe. Korean Air Lines Flight 902 was shot down in the USSR in 1978 after the crew made gross navigational errors attempting to fly the assigned polar route.

Routine transpolar flight deep into the Arctic became possible only after the end of the Cold War, when the United States and Russia became less concerned about the possibility of a trans-polar attack. Aircraft such as the Boeing 747-400
Boeing 747-400
The Boeing 747-400 is a major development and the best-selling model of the Boeing 747 family of jet airliners. While retaining the four-engine wide-body layout of its predecessors, the 747-400 embodies numerous technological and structural changes to produce a more efficient airframe...

 and the Airbus A340
Airbus A340
The Airbus A340 is a long-range four-engine wide-body commercial passenger jet airliner. Developed by Airbus Industrie,A consortium of European aerospace companies, Airbus is now fully owned by EADS and since 2001 has been known as Airbus SAS. a consortium of European aerospace companies, which is...

, with ranges of around 7000 nautical miles (12,964 km), were also required to handle the distances between suitable airports. Before this era, all flights from North America to Asia were routed around the Communist bloc using a series of tracks between Alaska and Japan.

The main obstacle to flights across Russia was the inadequate Russian air traffic control system and a lack of English communication. To solve these issues RACGAT (Russian-American Coordinating Group for Air Traffic) was formed in 1993. By summer 1998 the Russian government gave permission to open four cross-polar routes, named Polar 1, 2, 3 and 4 . Cathay Pacific
Cathay Pacific
Cathay Pacific is the flag carrier of Hong Kong, with its head office and main hub located at Hong Kong International Airport, although the airline's registered office is on the 33rd floor of One Pacific Place...

 flew the first polar flight into Siberia
Siberia
Siberia is an extensive region constituting almost all of Northern Asia. Comprising the central and eastern portion of the Russian Federation, it was part of the Soviet Union from its beginning, as its predecessor states, the Tsardom of Russia and the Russian Empire, conquered it during the 16th...

 in July 1998.

Polar routes are now in common use by airlines connecting Asian cities such as Singapore, Hong Kong, Beijing, Tokyo, and Seoul to North American destinations such as New York, Chicago, Washington, Detroit, and Toronto.

Antarctica

In the southern hemisphere, most intercity pairs do not result in a great circle route over Antarctica. Although direct flights between South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...

 and New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

 would overfly Antarctica, there never have been direct flights between those countries.

Aerolíneas Argentinas
Aerolíneas Argentinas
Aerolíneas Argentinas , formally Aerolíneas Argentinas S.A., is Argentina's largest airline and serves as the country's flag carrier. Owned in its majority by the Argentine Government, the airline is headquartered in the Torre Bouchard, located in San Nicolás, Buenos Aires...

 and LAN Chile operate nonstop services from New Zealand to Buenos Aires
Buenos Aires
Buenos Aires is the capital and largest city of Argentina, and the second-largest metropolitan area in South America, after São Paulo. It is located on the western shore of the estuary of the Río de la Plata, on the southeastern coast of the South American continent...

 and Santiago
Santiago, Chile
Santiago , also known as Santiago de Chile, is the capital and largest city of Chile, and the center of its largest conurbation . It is located in the country's central valley, at an elevation of above mean sea level...

, respectively, and Qantas
Qantas
Qantas Airways Limited is the flag carrier of Australia. The name was originally "QANTAS", an initialism for "Queensland and Northern Territory Aerial Services". Nicknamed "The Flying Kangaroo", the airline is based in Sydney, with its main hub at Sydney Airport...

 flies nonstop from Sydney
Sydney
Sydney is the most populous city in Australia and the state capital of New South Wales. Sydney is located on Australia's south-east coast of the Tasman Sea. As of June 2010, the greater metropolitan area had an approximate population of 4.6 million people...

 to Buenos Aires, forming the most southerly polar route. Depending on flight-level winds, these can approach 55 degrees southerly latitude, though not enough to cross the polar ice cap.

Operational considerations

The FAA's policy letter Guidance for Polar Operations (March 5, 2001) outlines a number of special requirements for polar flight, which includes two cold-weather suits, special communication capability, designation of arctic diversion airports
Diversion airport
Diversion airports are suitable airports capable of handling a particular ETOPS rated aircraft during an emergency landing and whose flying distance at the point of emergency shall not exceed the ETOPS diversion period of that particular aircraft....

 and firm recovery plans for stranded passengers, and fuel freeze strategy and monitoring requirements

Jet fuel
Jet fuel
Jet fuel is a type of aviation fuel designed for use in aircraft powered by gas-turbine engines. It is clear to straw-colored in appearance. The most commonly used fuels for commercial aviation are Jet A and Jet A-1 which are produced to a standardized international specification...

 freeze temperatures range between -40 and -50 °C. These temperatures are frequently encountered at cruise altitude throughout the world with no effect since the fuel retains heat from lower elevations, but the intense cold and extended duration of polar flights may cause fuel temperature to approach its freezing point. Modern long-distance airliners are equipped to alert flight crew when fuel temperatures reach these levels. The crew must then change altitude, though in some cases due to the low stratosphere
Stratosphere
The stratosphere is the second major layer of Earth's atmosphere, just above the troposphere, and below the mesosphere. It is stratified in temperature, with warmer layers higher up and cooler layers farther down. This is in contrast to the troposphere near the Earth's surface, which is cooler...

over polar regions and its inversion properties the air may actually be somewhat warmer at higher altitudes.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK