the Aviation Dictionary

gas generator turbine . gear and pinion mechanism
gas generator turbine - In gas turbine engines, high
pressure turbine wheel(s) which drive the compressor
of a turboshaft or turboprop engine.
gassing, battery - The release of hydrogen and oxygen
as a free gas during the charging cycle of lead-acid
storage batteries.
gas path - The airflow or open portion of the engine gate - 1. A logic device having one or more inputs
front to back where air is compressed, combusted, and andlor outputs. The condition of the inputs determines
exhausted. whether or not a voltage is present at the outputs. 2.
The electrode of a silicon-controlled rectifier or a triac
gas path analysis (GPA) - A computer analysis of
through which the trigger pulse is applied.
engine parameters on some airliners. It is designed to
assist the modular maintenance and on-condition gate hold procedures - Procedures at selected airports
maintenance concepts by giving continuous that require aircraft to hold at the gate or other ground
on-condition data. Also used for predicting engine locations whenever departure delays exceed or are
component airworthiness.
anticipated to exceed 15 minutes. Departure sequence
is maintained in accordance with initial call-up unless
gas storage cylinders - Long bottles of high-strength
modified by flow control restrictions. Pilots should
steel used to store compressed gases.
monitor the ground control/clearance delivery
gas turbine - Engine consisting of a compressor, frequency for engine stadtaxi advisories or new
combustor and turbine, using a gaseous fluid as a proposed stadtaxi times if the delay changes.
working medium and producing either shaft gaterype check valve - A one-way flow valve having a
horsepower, jet thrust, or both. The four common types
swinging gate or flapper. The gate-type check valve
of Gas Turbine Engines are Turbojet, Turbofan,
can isolate one of the vacuum pumps in a multi-engine
Turboprop and Turboshaft.
aircraft from the rest of the svstem in the event of a
gas turbine engine - A heat engine in which burning failure of the pump.
fuel adds energy to compressed air and accelerates the
gateway fix - A navigation aid or fix where an aircraft
air through the remainder of the engine. Some of the
transitions between the domestic route structure and the
energy is extracted to turn the air compressor, and the
oceanic route airspace.
remainder accelerates the air to produce thrust. A
portion of this energy can be converted into torque to gauge - Any of a variety of measuring instruments.
drive a propeller or a system of rotors for a helicopter. Some are used to indicate the amount of air pressure,
the depth of a hole or a groove, or possibly the
gas welding - The method of fusing metals together by
thickness or clearance between close-fitting parts of a
a flame using gas as fuel. The most common types of
machine, etc.
gas welding use oxygen and acetylene gas
(oxyacetylene) and oxygen and hydrogen gauge pressure - Pressure measured relative to the
(oxyhydrogen).
existing atmospheric pressure. Engine oil pressure and
gaseous - Having the nature or form of gas.
hydraulic are normally measured as gauge
pressure. If gauge pressure is measured in pounds per
gaseous breathing oxygen - Oxygen that is 99.5% pure square inch, it is referred to as PSlG (pounds per
and contains practically no water vapor.
square inch, gauge). Two other types of pressure that
are often used are differential pressure (PSID) and
gaseous fuel - Any mixture of flammable gases used for
absolute pressure (PSIA). Differential pressure is the
fuel.
difference between two pressures and absolute pressure
gas-filled tube - An electron tube with gas introduced is a value compared to zero pressure.
'"0 the envelo~e '0 ~'oduce certain desired o~era~ing
gauss - ~h~ unit of magnetomotive force. ~t is equal to
characteristics.
one maxwell per cm2.
gasket - The static, stationary between two flat
gear A toothed wheel or disc that meshes with another
surfaces.
toothed wheel or disc to transmit motion.
gasoline - A volatile, highly flammable liquid mixture
gear and pinion mechanism - A mechanical
of hydrocarbons produced by the fractional distillation
amplifying mechanism consisting of two gears, one
of petroleum and used as fuel in internal-combustion
being a pinion, which is much smaller than the other.
engines.
The mechanical advantage of the mechanism is detergasoline
combustion heaters -- Aircraft cabin heaters mined by the ratio between the number of teeth on the
that bum gasoline from the aircraft fuel tanks to pinion and the number of teeth on the large gear. Often
produce the required heat.
the large gear is only a portion of the wheel and is
called a sector gear.
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