Induce
verb to bring about,to cause to happen o If a coil carrying a changing current is placed near another coil, the changing magnetic field cuts the other coil and induces a voltage in it. o Unequal deposits on moving parts can induce severe vibration especially on propellers and helicopter rotors.
induced drag
noun part of total drag, created by lift
There are two basic types of drag, induced drag and parasite drag.
comment: Induced drag is created when high-pressure air below a wing rotates around the tip to the low-pressure area above and increases as airspeed decreases and angle of attack increases.
inductance
noun a measure of a conductor’s ability to bring a voltage into itself when carrying a changing current, e.g. during short times when the circuit is switched on or off o At low frequencies, the rate of collapse of the magnetic field will be slow and the inductance will be low.
induction
noun 1. the process by which the fuel/air mixture is drawn into the cylinders of an internal combustion engine o The four strokes of the engine are induction, compression, combustion and exhaust. 2. the production of electrical current in a conductor by a change of magnetic field o A transformer is a static device that changes the amplitude or phase of an alternating voltage or current by electro-magnetic induction.
inductive
adjective referring to the production of electrical current in a conductor by a change of magnetic field o One side effect of low frequency in an inductive circuit is that excess heat may be produced.
inductor
noun a component in the ignition system that produces electrical current in itself by a change of magnetic field
inert
adjective not reacting with other substance
inert gas
noun a gas that does not react with other substances o Inert gases, dust, smoke, salt, volcanic ash, oxygen and nitrogen together constitute 99%o of the atmosphere. (note: The inert gases include helium, neon, argon, krypton and xenon.)
inertia
noun the tendency of a body at rest to stay at rest or of a moving body to continue moving in a straight line unless acted on by an outside force o Inertia switches operate automatically when a particular g (acceleration due to Earth’s gravity) loading occurs.
inertial
adjective referring to inertia
inertial navigation system
noun a navigation system which calculates aircraft position by comparing measurements of acceleration with stored data, using gyros rather than radios.
Abbreviation INS
inferential
adjective obtained by deduction o The inferential method of ice detection is used in flight trials for aircraft certification.
inflammable
adjective easily set on fire o Petrol is an inflammable liquid. (note: Flammable and inflammable mean the same thing.) □ highly inflammable very easily set on fire, and therefore hazardous
inflate
verb to blow air into something and thereby increase its size o A sharp pull on the cord will discharge the gas bottle and inflate the life jacket.
Opposite deflate inflation
noun 1. the act of blowing air into something, e.g. a balloon or a tyre, and so increasing its size Tyre inflation pressures should be maintained within 4% limits. 2. a continuing increase in the price of things and a decrease in the buying power of money o Annual inflation is 4%.
Opposite deflation
in-flight
adjective taking place during a flight in-flight emergency in-flight oil loss
influence
noun a power which affects people or things o The Atlantic Ocean has a great influence on the climate of the British Isles. ■ verb to have an effect on, to change o In an emergency, a crew member’s power of command will influence the reaction of passengers.
inform
verb to tell some body something o After a particularly heavy landing, the pilot should inform an engineer so that checks can be made to the aircraft structure.
information
noun a collection of facts or data o Meteorological visibility gives information on the transparency of the atmosphere to a stationary ground observer. (note: Information has no plural form.)
infra-
prefix below or beneath
infrared
‘, infra-red adjective referring to the range of invisible radiation wavelengths from about 750 nanometres to 1 millimetre Solar radiation is short wave and of high intensity while terrestrial radiation is infra-red.
infrequent
adjective not often o In northern Europe, thunderstorms are infrequent in winter time.
ingest
verb to take in, or to absorb into, something such as a jet engine through the intake o Jet engines may be damaged by ingested chunks of ice.
ingestion
noun the act of taking something into something such as a jet engine through the intake o Ingestion of birds may seriously damage the blades of turbo-fan engines.
inherent
‘ adjective existing as a basic or fundamental characteristic o A boiling point of 100°C is an inherent characteristic of water. in hg noun the unit for measuring absolute pressure.
Full form inch(es) of mercury
inhibit
verb to prevent or to limit the effect of something o Cloud cover inhibits cooling of the Earth’s surface at night.
inhibition
noun the prevention or limitation of the effect of something o Fuel contains chemicals for the inhibition of fungal growth.
inhibitor
‘ noun a device or substance which prevents or limits the effect of something □ icing inhibitor a substance added to fuel to prevent fuel system icing
initial _ adjective relating to 
or occurring at the beginning, the first □ initial climb the period of climb immediately after take-off □ initial letter the first letter of a word □ initial stage first stage ■ noun the first letter of a word
initials
plural noun the first letters of a name o His name is John Smith, his initials are JS.
initiate
verb to get some thing going by taking the first step, to start o In a serious emergency, a member of the cabin crew may initiate an evacuation of the aircraft.
initiation
noun the act of getting something going by taking the first step, starting o Normally speaking, the captain is responsible for the initiation of emergency procedures.
initiative
noun the power or ability to begin or to follow through competently with a plan or task o Crew members must be able to act collectively and with initiative in unusual situations.
inject
verb to force or drive a fluid into something o An accelerator pump, operated by the movement of the throttle lever, injects fuel into the choke tube.
injection
‘ noun the forcing of fluid into something o Power output can be boosted to a value over 100% maximum power, by the injection of a water methanol mixture at the compressor inlet or at the combustion chamber inlet.
injector
noun a device that will force or drive a fluid into something
injury
noun damage or harm done to a person o Escape slides are designed to minimise the risk of injury to passengers when leaving the aircraft.
inland
adjective, adverb referring to the interior of a country or land mass o Sea fog can extend for considerable distances inland.
inlet
noun 1. an opening which allows an intake of something o turbine inlet o combustion chamber inlet o Air enters the cabin through an inlet. 2. a coastal feature such as at the mouth of a river
inlet valve
noun the valve in a piston engine which allows fuel to enter the cylinder
inner
adjective positioned farther inside □ inner wing the part of the wing near the fuselage
inner marker
noun an ILS marker beacon placed between the middle marker and the end of the ILS runway
inoperative
adjective not functioning o To prevent accidental retraction of the undercarriage, a safety switch is fitted in such a way to the oleo, that when it is compressed on the ground, the ‘undercarriage up’ selection is inoperative.
input
/ noun something such as energy, electrical power or information, put into a system to achieve output or a result o Pumps require high input cur-rent. o If the number of turns on the secondary winding is greater than the number of turns on the primary, the output voltage from the secondary will be greater than the input voltage to the primary. □ pilot control input movements on the flying controls made by the pilot
INS abbreviation inertial navigation system
insert
verb to put in or into To prevent tyre explosion due to overheating, fusible plugs are inserted into the wheel assemblies. o Insert your telephone number in the space provided on the form. o Insert the key in the lock and turn it.
insertion
_ noun the act of putting in or into o There is a space on the form for the insertion of a postal address. o When the contours for a particular pressure level have been drawn in, the chart is completed by insertion of spot temperatures and wind speed information.
insignificant
adjective not important, of no consequence o Minor changes in wind speed or direction are insignificant.
inspect
verb to look at something closely and to check for problems or defects o Propellers should be inspected prior to flight.
inspection
noun a careful check for problems o Before flight, the pilot should carry out a careful inspection of the aircraft.
instability
noun a condition in which a body or mass moves easily, and with increasing speed, away from its original position o Atmospheric instability often results in strong vertical currents of air. o The built-in instability of some modern fighter aircraft makes them highly maneuverable but difficult to control without fly-by-wire technology.
install
verb to put in position, connect and make ready for use o Most carburetors are installed in a warm position to help against icing. □ installed battery a battery in position in the aircraft
installation
‘ noun 1.the act of putting equipment or devices into position and connecting them for use o The installation of the computer took three hours. 2. equipment or devices which are installed o In some auxiliary-power-unit installations the air intake area is protected against ice formation by bleeding a supply of hot air from the compressor over the intake surfaces.
instance
noun an example which is used to provide evidence of something o Failure to check fuel levels before take-off is an instance of bad airmanship. □ for instance e.g.
instant
adjective immediate, happening immediately ■ noun a very short period of time o The pilot has to act in an instant to counteract the severe downdraughts of a microburst.
instinctive
adjective natural, rather than thought-out o In most modern light aircraft, use of the trim wheel is instinctive, i.e. forwards for nose down and backwards for nose up.
instruct
verb to give information or knowledge, usually in a formal setting such as a lesson or briefing o The safety officer instructs employees on the use of the breathing equipment. o The training captain instructs trainee pilots in the simulator.
instruction
/ noun 1. the act of giving information or knowledge, usually in a formal setting such as a lesson or briefing o Trainees receive first-aid instruction. 2. information on how something should be operated or used You must follow the instructions.
instructor
noun a person who gives information or knowledge, usually in a formal setting such as a lesson or briefing
instrument
noun a device for recording, measuring or controlling, especially functioning as part of a control system Airspeed is given on an instrument called the airspeed indicator.
instrument approach procedure
noun a set of procedures which a pilot must follow when approaching an airport under instrument flight rules
instrumentation
noun a set of specialised instruments on an aircraft o Instrumentation in some basic light aircraft is restricted to a few instruments only. o Some modern light aircraft have very sophisticated instrumentation.
instrument error
noun the difference between indicated instrument value and true value instrument flight rules 
‘ plural noun regulations which must be followed when weather conditions do not meet the minima for visual flight o The flight from Manchester to Prestwick was conducted under instrument flight rules.
Abbreviation IFR
instrument flying
noun flying using no references other than the flight instruments o Some conditions require instrument flying. o When in cloud, instrument flying is required.
Abbreviation IF
instrument landing
noun the landing of an aircraft when a pilot is relying on information obtained from instruments rather than from what can be seen outside the aircraft
instrument landing system
noun aids for an instrument landing approach to an airfield, consisting of a localizer, glide slope, marker beacons and approach lights o The instrument landing system provides both horizontal and vertical guidance to aircraft approaching a runway. Abbreviation ILS
comment: The ILS is the most used precision approach system in the world.
instrument meteorological conditions
plural noun meteorological conditions of visibility and distance from cloud ceiling which are less than those for visual meteorological conditions o The basic licence does not permit the pilot to fly in instrument meteorological conditions.
Abbreviation IMC
Instrument rating
noun an additional qualification added to a license, such as PPL, allowing a pilot to fly in instrument meteorological conditions o He gained his instrument rating in 1992.
Abbreviation I/R
Comment: An instrument rating is required for operating in clouds or when the ceiling and visibility are less than those required for flight under visual flight rules (VFR).
