the Aviation Dictionary

water jet weft direction
water jet - Used primarily in the manufacturing process
as a cutting tool. A very high-pressure stream of water
is used to cut through the component.
water vapor - The gaseous form of H20.
water-injection system - A system in which water is
injected along with the fuel to avoid damage to the
engine. As compression ratios are raised, or
supercharging/turbocharging is added to engines,
temperatures rise and an increased chance of
detonation arises. Adding water injection provides a
waterlairlfuel mixture that not only bums more
efficiently and avoids spontaneous detonation but also
provides additional inlet air cooling and, hence, denser
air.
waterspout - A tomado that occurs over water.
watt - The basic unit of electrical power. One ampere
flowing under a pressure of one volt is equal to one
watt. One watt equals '1746 HP.
wattage rating - The maximum amount of power an
electrical component needs to operate an appliance or
device without damaging the device.
watt-hour -A unit of electrical energy equal to one watt
acting for one hour.
wattmeter -An instrument designed to measure electric
power in watts.
watt-second - A unit of electrical energy equal to one
watt acting for one second.
wave carrier - An electromagnetic wave of highfrequency
alternating current whose modulations are
used to transmit speech, images, and other signals. The
more common term is carrier wave.
wave cyclone - A cyclone that forms and moves along a
fiont. The circulation about the cyclone center tends to
produce a wavelike deformation of the front.
wave soldering - A method of soldering printed circuit
boards where the board is placed slightly above a
container of molten solder. A wave is induced in the
solder and the resultant rise in level coats the exposed
leads, simultaneously soldering all component leads on
the board.
wave window - Special areas arranged by Letter of
Agreement with the controlling ATC wherein gliders
can be allowed to fly under VFR in Class A Airspace at
certain times and to certain specified altitudes.
waveform - The shape of an electrical signal as seen on
an oscilloscope. Examples of wave forms are sine
waves and square waves.
waveguide - A hollow metal tube designed to guide
electromagnetic energy.
wavelength - The distance between the crests of a wave
of energy. Wavelength is inversely proportional to the
frequency of the wave.
way point - A predetermined geographical position
used for routelinstrument approach definition, progress
reports, published VFR routes, visual reporting points
or points for transitioning, and/or circumnavigating
controlled andlor special use airspace. Defined relative
to a VORTAC station or in terms of latitudellongitude
coordinates.
waypoint - A specified geographic location used to
define an area navigation route or flight path of an
aircraft employing area navigation. Waypoints are
identified as either fly-by or fly-over.
wear pads - In aircraft brakes, steel pads riveted to the
surfaces of the stationary disks, the pressure plate, and
the back plate to provide a wearing surface against the
sintered material on the rotating disks. It is more
economical to replace the wear pads than the disks and
the plates themselves.
weather - The instantaneous state of the atmosphere.
weather advisory - In aviation weather forecast
practice, an expression of hazardous weather
conditions not predicted in the area forecast, as they
affect the opera;ion of air traffic and as by thk
NWS (National Weather Service).
weather vane -A wind vane.
weave - In composites, the particular manner in which a
fabric is formed by interlacing yams. Usually assigned
a style number used in ordering for the repair of a
component.
web - The portion of any beam or channel that lies
between the flanges of a spar, rib, or channel section.
Furnishes the strength necessary for longitudinal shear
loads.
web browser -A software program that provides access
to sites on the World Wide Web (WWW).
web of a beam - The portion of a beam that lies
between the flanges of a spar, rib, or channel section.
Furnishes the strength necessary for longitudinal shear
loads.
weber - A basic metric unit of magnetic flux equal to
that flux produced in a single tum of wire when an
EMF of one volt is reduced to zero at a uniform rate of
one ampere per second.
wedge - A tapered hard piece of wood or metal that can
be used for splitting, tightening, securing, or levering.
weft direction - Fibers that are perpendicular to the
warp fibers. Sometimes referred to as the woof or fill.
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