Clean configuration is the
flight configuration of a
fixed-wing aircraft
A fixed-wing aircraft is a heavier-than-air Aircraft, flying machine, such as an airplane, which is capable of flight using wings that generate Lift (force), lift caused by the aircraft's forward airspeed and the wing configuration, shape of ...
when its external equipment is retracted to minimize
drag
Drag or The Drag may refer to:
Places
* Drag, Norway, a village in Tysfjord municipality, Nordland, Norway
* ''Drág'', the Hungarian name for Dragu Commune in Sălaj County, Romania
* Drag (Austin, Texas), the portion of Guadalupe Street adj ...
, and thus maximize
airspeed
In aviation, airspeed is the speed of an aircraft relative to the air. Among the common conventions for qualifying airspeed are:
* Indicated airspeed ("IAS"), what is read on an airspeed gauge connected to a Pitot-static system;
* Calib ...
for a given power setting.
For most
airplane
An airplane or aeroplane (informally plane) is a fixed-wing aircraft that is propelled forward by thrust from a jet engine, propeller, or rocket engine. Airplanes come in a variety of sizes, shapes, and wing configurations. The broad spe ...
s, clean configuration means simply that the
wing
A wing is a type of fin that produces lift while moving through air or some other fluid. Accordingly, wings have streamlined cross-sections that are subject to aerodynamic forces and act as airfoils. A wing's aerodynamic efficiency is exp ...
flaps and
landing gear
Landing gear is the undercarriage of an aircraft or spacecraft that is used for takeoff or landing. For aircraft it is generally needed for both. It was also formerly called ''alighting gear'' by some manufacturers, such as the Glenn L. Marti ...
are retracted, as these are the cause of drag due to the lack of
streamlined shape. On more complex
airplane
An airplane or aeroplane (informally plane) is a fixed-wing aircraft that is propelled forward by thrust from a jet engine, propeller, or rocket engine. Airplanes come in a variety of sizes, shapes, and wing configurations. The broad spe ...
s, it also means that other devices on the wings (such as
slats,
spoilers, and leading edge
flaps) are retracted. Clean configuration is used for normal cruising at altitude during which lift, or rise in altitude, is not needed.
In military aviation, a clean configuration is generally without
external stores which reduce maximum performance both due to increased weight and even more so due to increased drag.
[https://books.google.com/books?id=kaqvC4e_EKcC&pg=PA246&dq=%22clean+configuration%22+stores&hl=en&sa=X&ved=2ahUKEwjg8sCyydbrAhUKlFkKHfEmDiMQ6AEwAXoECAIQAQ#v=onepage&q=%22clean%20configuration%22%20stores&f=false page 246]
References
Aerospace engineering
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