Runway

In aviation, a runway is an elongated, rectangular surface designed for the landing and takeoff of an aircraft. Runways may be a human-made surface (often asphalt, concrete, or a mixture of both) or a natural surface (grass, dirt, gravel, ice, sand or salt). Runways, taxiways and ramps, are sometimes referred to as "tarmac", though very few runways are built using tarmac. Takeoff and landing areas defined on the surface of water for seaplanes are generally referred to as waterways. Runway lengths are now commonly given in meters worldwide, except in North America where feet are commonly used.

History

In January 1919, aviation pioneer Orville Wright underlined the need for "distinctly marked and carefully prepared landing places, [but] the preparing of the surface of reasonably flat ground [is] an expensive undertaking [and] there would also be a continuous expense for the upkeep."

In 1919, based on WWI experience, the United States Army Air Service published Specifications for Municipal Landing Fields. It specified an 1800 by 1800 foot square with a central 150 foot takeoff runway in the shape of a cross. Through the 1930s though, most army planes landed in any direction, subject to the prevailing winds, on circular groomed and drained turf called "all-over fields." However, tire pressures were limited to less than seventy psi in such fields. After 1935, tire pressures exceeded that limit with increased aircraft size. According to Conway, "Confronted with snow and ice removal in the north, water nearly everywhere, and the demands placed by airlines on regularity, safety, and efficient transshipment of passengers and mail, the technology of the all-over turf field became obsolete in the United States during the 1920s." In 1928, Ford Airfield became the first U.S. airport to have concrete runways, and by 1932, all major U.S. airports had runways..."

Design

Orientation

The primary consideration in determining runway orientation is the prevailing wind direction, in lieu of spatial constraints or obstructions that may prevent optimal alignment.