drag surface
61Wing configuration — For aircraft configurations in general, including fuselage, tail and powerplant configuration, see Aircraft. For rotary winged aircraft types, see Rotorcraft. For direct lift and compound or hybrid types, see Powered lift. Fixed wing aircraft,… …
62D'Alembert's paradox — In fluid dynamics, d Alembert s paradox (or the hydrodynamic paradox) is a contradiction reached in 1752 by French mathematician Jean le Rond d Alembert.[1] D Alembert proved that – for incompressible and inviscid potential flow – the drag force… …
63Gravity turn — A gravity turn or zero lift turn is a maneuver (see trajectory optimization) used in launching a spacecraft into, or descending from, an orbit around a celestial body such as a planet or a moon. This launch trajectory offers two main advantages… …
64Friction — For other uses, see Friction (disambiguation). Classical mechanics …
65Aileron — For the band, see The Ailerons …
66Atmospheric reentry — refers to the movement of human made or natural objects as they enter the atmosphere of a planet from outer space, in the case of Earth from an altitude above the edge of space. This article primarily addresses the process of controlled reentry… …
67Sand casting — Sand casting, also known as sand molded casting, is a metal casting process characterized by using sand as the mold material. It is relatively cheap and sufficiently refractory even for steel foundry use. A suitable bonding agent (usually clay)… …
68military aircraft — Introduction any type of aircraft that has been adapted for military use. Aircraft have been a fundamental part of military power since the mid 20th century. Generally speaking, all military aircraft fall into one of the following… …
69Ground effect in aircraft — Aircraft may be affected by a number of ground effects, aerodynamic effects due to a flying body s proximity to the ground.One of the most important of these effects is the Wing In Ground effect, which refers to the reduction in drag experienced… …
70Propeller — A propeller is essentially a type of fan which transmits power by converting rotational motion into thrust for propulsion of a vehicle such as an aircraft, ship, or submarine through a mass such as water or air, by rotating two or more twisted… …
