Aircraft design

The aircraft design process is a loosely defined method used to balance many competing and demanding requirements to produce an aircraft that is strong, lightweight, economical and can carry an adequate payload while being sufficiently reliable to safely fly for the design life of the aircraft. Similar to, but more exacting than, the usual engineering design process, the technique is highly iterative, involving high-level configuration tradeoffs, a mixture of analysis and testing and the detailed examination of the adequacy of every part of the structure. For some types of aircraft, the design process is regulated by civil airworthiness authorities. This article deals with powered aircraft such as airplanes and helicopter designs. The design process starts with the aircraft's intended purpose. Commercial airliners are designed for carrying a passenger or cargo payload, long range and greater fuel efficiency where as fighter jets are designed to perform high speed maneuvers and provide close support to ground troops. Some aircraft have specific missions, for instance, amphibious airplanes have a unique design that allows them to operate from both land and water, some fighters, like the Harrier jump jet, have VTOL (vertical take-off and landing) ability, helicopters have the ability to hover over an area for a period of time. The purpose may be to fit a specific requirement, e.g. as in the historical case of a British Air Ministry specification, or fill a perceived "gap in the market"; that is, a class or design of aircraft which does not yet exist, but for which there would be significant demand. Another important factor that influences the design are the requirements for obtaining a type certificate for a new design of aircraft. These requirements are published by major national airworthiness authorities including the US Federal Aviation Administration and the European Aviation Safety Agency. Airports may also impose limits on aircraft, for instance, the maximum wingspan allowed for a conventional aircraft is to prevent collisions between aircraft while taxiing.