the Aviation Dictionary

Notices To Airmen Publication (NOTAM) . nvlon
National Airspace System) the timely knowledge of
which is essential to personnel concerned with flight
operations.
a. NOTAM(D) - A NOTAM given (in addition to local
dissemination) distant dissemination beyond the area of
responsibility of the Flight Service Station. These
NOTAMs will be stored and available until cancelled.
b. NOTAM(L) - A NOTAM given local dissemination
by voice and other means, such as telautograph and
telephone, to satisfy local user requirements.
c. FDC NOTAM - A NOTAM regulatory in nature,
transmitted by USNOF and given system wide
dissemination.
Notices To Airmen Publication (NOTAM) - A
publication issued every 28 days, designed primarily
for the pilot, which contains current NOTAM
information considered essential to the safety of flight
as well as supplemental data to other aeronautical
publications. The contraction NTAP is used in
NOTAM text.
nozzle - The tapered end of a duct.
nozzle blades - Any of the blades of a nozzle
diaphragm.
nozzle diaphragm - A ring of stationary blades in a
turbine engine ahead of the turbine wheel. Used to
direct the flow of hot gases into the turbine for
maximum efficiency.
nozzle, fuel - The pressure-atomizing unit that receives
fuel under high pressure from the fuel manifold and
delivers it to the combustor in a highly atomized,
precisely patterned spray.
NPN transistor - A three-element semiconductor made
up of a sandwich of P-type silicon or germanium
between two pieces of N-type material.
N-strut - Struts of a biplane near the wing tips shaped in
the form of the letter N.
N-type semiconductor material - A semiconductor
material that has been doped (an impurity added) that
leaves the outer ring of the valence shells with
electrons that are readily given up.
N-type silicon - Silicon that has been doped with an
impurity having five valence electrons.
nuclear energy - Energy released as a result of either
nuclear fission, nuclear fusion, or radioactive decay.
Nuclear fusion is not yet commercially feasible.
nuclear fission - The splitting of an atomic nucleus
resulting in the release of energy.
nuclear fusion - The union of atomic nuclei of certain
light elements to form heavier nuclei resulting in the
release of energy.
nuclei -Plural of nucleus.
nucleonics - The branch of science that deals with
atomic nuclei and nuclear energy.
nucleus - 1. The center or core around which other parts
are grouped. 2. The center or co~e of an atom
consisting of positively charged protons and uncharged
neutrons.
nucleus of an atom - In chemistry, the central portion
of an atom.
null -An indicated low or zero point in a radio signal.
null balance - An electrical circuit in which two
voltages have cancelled each other out.
null detector - An electrical instrument that determines
values by adjusting a known quantity until it is
identical with the quantity to be measured. Often
utilizes a Wheatstone bridge.
numbers - A symbol used to assign a value of quantity
or placement in a sequence.
numerator - The part of a fraction that illustrates a
portion of something that makes up a whole. In
decimals, the numerator is the number to the right of
the decimal point. In a fraction, it is the number above
the line and signifies the number of parts of the
denominator used.
numerical control - Allows more precise control of
operations than analog control. Also referred to as
digital control.
numerical weather prediction - Meteorological
forecasting using digital computers to solve
mathematical equations that describe the physics of the
atmosphere; used extensively in weather services
throughout the world.
numerous targets vicinity (location) - A traffic
advisory issued by ATC to advise pilots that targets on
the radar scope are too numerous to issue individually.
nut - An internally threaded collar used to screw onto
bolts or screws to form a complete fastening device.
nutation - The wobbling of the axis of a spinning body
such as the Earth, or a gyroscope.
nutplate - A nut that can be riveted to the inside of a
structure. Bolts and screws can be screwed into the
nutplate without a wrench to hold the nut in place.
nylon -A tough, lightweight, elastic polyarnide material
used especially in fabrics and plastics.
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