the Aviation Dictionary

interstage transformer IR drop
interstage transformer - A transformer used to prevent
the flow of DC from one stage of a multi-stage
transformer system to the other. Provides the correct
amount of impedance for the AC output of one stage
and for the AC input of the following stage.
interstate air commerce - The carriage by aircraft of
persons or property for compensation or hire, or the
carriage of mail by aircraft, or the operation
ornavigation of aircraft in the conduct or hrtherance of
a business or vocation, in commerce between a place in
any State of the United States, or the ~ishct of
Columbia, and a place in any other State of the United
States, or the District of Columbia; or between places
in the same State of the United States through the
airspace over any place outside thereof; or between
places in the same territory or possession of the United
States, or the District of Columbia.
interstate air transportation - The carriage by aircraft
of persons or property as a common carrier for
compensation or hire, or the carriage of mail by aircraft
in commerce: a. Between a place in a State or the
District of Columbia and another place in another State
or the District of Columbia, b. Between places in the
same State through the airspace over any place outside
that State; or c. Between places in the same possession
of the United States; Whether that commerce moves
wholly by aircraft of partly by aircraft and partly by
other forms of transportation. Intrastate air
transportation means the carriage of persons or
property as a common carrier for compensation or hire,
by turbojet-powered aircraft capable of carrying thirty
or more persons, wholly within the same State of the
United States.
intertropical convergence zone - The boundary zone
between the trade wind system of the Northern and
Southern Hemispheres; it is characterized in maritime
climates by showery precipitation with cumulonimbus
clouds sometimes extending to great heights.
introduction - The first element of an instructional
lesson that sets the stage for the rest of the lesson by
relating the coverage of the material to the entire
course. The introduction itself is typically composed of
three elements: attention, motivation, and an overview
of what is to be covered.
Invar - A nickel-iron alloy with an extremely small
temperature coefficient of expansion.
inverse peak voltage - The amount of inverse voltage a
device can withstand without breakdown.
inverse square law - In physics, a given physical
quantity varies inversely with the square of another
physical quantity (usually distance). For example, if the
distance fiom a magnet doubles, the strength of
magnetism decreases to one fourth of its original value.
inverse voltage - The amount of voltage seen by a
rectifier during the half cycle of AC being blocked to
create pulsed DC.
inversion - In meteorology, an increase in temperature
with height - a reversal of the normal decrease with
height in-the troposphere; may also be applied to other
meteorological properties.
invert - To reverse the position, order, or condition of
something.
inverted engine - A reciprocating engine whose
crankshaft and crankcase are above the cylinders.
inverted spin - A maneuver having the characteristics
of a normal spin except that the airplane is in an
inverted attitude.
inverter - An electrical device that changes DC to AC.
investment casting - Casting as in a vacuum furnace or
spin chamber to produce a denser, better quality
material. Used to produce some steels in turbine
engines.
iodine -A poisonous element with a symbol of I and an
atomic number of 53.
ion - An atom that has either gained or lost an electron.
If an atom has a shortage of electrons, it is a positive
ion. If it possesses an excess of electrons, it is a
negative ion.
ion engine - A reaction engine that ejects a stream of
ionized particles to produce a forward thrust.
ionic charges - The charges in solid-state junctions
caused by the dissimilarity of the junction materials.
The charges create "barrier voltages." In order for a
diode to rectify, it must be presented with an AC
voltage whose peak value exceeds its barrier voltage.
ionize - To convert totally or partially into ions.
ionosphere - A series of atmospheric layers of ions that
begins approximately 25 miles above the surface of the
Earth.
IR - 1. Voltage. Since E (voltage) = I (current) times R
(resistance), IR is another way of stating E, or voltage.
2. Routes used by the Department of Defense and
associated Reserve and Air Guard units for the purpose
of conducting low-altitude navigation and tactical
training in both IFR and VFR weather conditions
below 10,000 feet MSL at airspeeds in excess of 250
knots IAS. [Jeppesen does not chart these routes.]
IR drop - The amount voltage drops in a given
conductor due to the resistance of the conductor. The
IR drop is found by the formula: I x R=E (voltage), or
by multiplying the amount of current (I) in amps, by
the amount of resistance (R) in ohms.
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