Unit 4 Aerospace Terms

4.1.1	Wash In/ Wash Out	A built in twist in the wing so that the trailing edge at the wingtip is raised (Wash out) or lowered (Wash in). This significantly affects the slow flight and stall characteristics of the wing.
4.1.3	Boudary Layers	A thin layer of air next to the surface of an airfoil which shows a reduction in speed due to the air's viscosity.
4.2.1	Moon	A natural satellite of a planet.
4.2.10	MSL	Mean Sea Level
4.2.11	NDB	Non-directional Beacon. An L/MF or UHF radio beacon transmitting non-directional signals whereby the pilot of an aircraft equipped with direction-finding equipment can determine their bearing to or from the radio beacon and "home" on or track to or from the station.
4.2.12 & 1.3.8	NGO	Non-Government Organizations.
4.2.3	Deformation	Any alteration of shape or dimensions of a body caused by stresses, thermal expansion or contraction, chemical or metallurgical transformations, or shrinkage and expansions due to moisture change.
4.2.3	O:
4.2.3	Open Loop System	A control circuit in which the system output has no effect on the control.
4.2.3 & 4.2.4	Output	The information produced by a computer.
4.2.4	Moment of Interia	A mathematical property of a cross section that is concerned with a surface area and how that area is distributed about a centroidal axis.
4.2.4	Perigee	The point in an orbit that is closest to earth
4.2.4	Switch	A device for making, breaking, or changing the connections in an electrical circuit.
4.2.4	Photopic Vision	Use of color-sensitive cones for direct vision in good light.
4.2.5	Pilotage	Navigation by visual reference to landmarks.
4.2.5	Pitch	Motion around the lateral axis caused by deflection in the elevator controlled by moving the yoke forward and aft.
4.2.5	Power Stroke	When the spark plug fires and the compressed mixture is ignited to begin the power stroke.
4.2.6	Propellant	A mixture of fuel and oxidizer that burns to produce rocket thrust.
4.2.6	Pupil	The opening in the iris, which admits light into the interior of the vertebrate eye; muscles in the iris regulate its size.
4.2.6	Resilience	A mechanical property of a material that shows how effective the material is absorbing mechanical energy without sustaining any permanent damage.
4.2.7	Retina	The sensory membrane that lines most of the large posterior chamber of the vertebrate eye; composed of several layers including one containing the rods and cones; functions as the immediate instrument of vision by receiving the image formed by the lens and converting it into chemical and nervous signals which reach the brain by way of the optic nerve.
4.2.8	Reynolds Number	The ratio of inertial forces to viscous forces.
4.2.9	Right Ascension of the Acending Node	Abbreviated as RAAN. The angle measured along the equatorial plane between a vector pointing to a fixed reference point in space and the point on the orbit where the orbital motion is from south to north across the equator.
	Turbojet	A type of gas turbine engine with no bypass.
	Syntax	The set of rules that defines the combinations of symbols that are considered to be correctly structured in that language. The grammar and spelling of text-based programming languages.
	TACAN	Tactical Air Navigation. An ultra-high frequency electronic rho-theta air navigation aid which provides suitably equipped aircraft a continuous indication of bearing and distance to the TACAN station.
	Taper	Tactical Air Navigation. An ultra-high frequency electronic rho-theta air navigation aid which provides suitably equipped aircraft a continuous indication of bearing and distance to the TACAN station.
	Turboprop	A turbojet engine that has a propeller mounted on the shaft ahead of the inlet.