1Dk4eXg

general-purpose aircraft
general-purpose aircraft Military aircraft intended to fill
multiplicity of roles; nearest modern equivalent is armed
utility.
generate To get a combat aircraft airborne and thus * a
sortie.
generation Family of all examples of particular hardware
species designed at same time to meet similar
requirements; after first * hard to define, and word generally
used to impress audience of prior experience of
particular manufacturer in field concerned.
generator 1 Machine for generating direct current.
Invariably used incorrectly to mean alternator.
2 Device for producing clearly visible smoke, e.g. for
aerobatics or for wind-tunnel.
generator line contactor Main circuit-breaker between
generator (ie, alternator) and AC bus.
generic A particular meaning: using same region of EM
spectrum for land, sea and air stations.
Genova General overall validation for ATM (7) (Euret).
gentle turn Primary flight manoeuvre in which bank
angle does not exceed 25°.
Gen-X Generic expendable[s].
GEO Geostationary Earth orbit.
GEOAP Ground equivalent onboard attitude
processor.
geocentric Related to centre of Earth.
geodesic line Shortest line between two points on mathematically
derived surface; ** on Earth called geodetic
line.
geodesic radome Spherical enclosure for large surface or
ship radar whose structural members are geodetics and
whose panels are perpendicular to transmissions.
geodesy Science which deals mathematically with size
and shape of Earth and its gravitational field, esp. with
surveys of such precision that these measures must be
taken into consideration.
geodetic construction Methods of making curved space
frames in which members follow geodesics along surface,
each experiencing either tension or compression; resulting
basketlike framework does not need stress-bearing
covering.
geodetic height Height above the surface of the Earth
(represented as an oblate spheroid) measured along a
normal to the surface, symbol h.
geodetic latitude The angle between the geodetic equatorial
plane and the normal to the surface, positive in N
hemisphere, negative in S, symbol φ.
geodetic position Location of a point on the surface of
the geosphere, defined by geodetic latitude, longtitude
and height.
GEODSS Ground-based electro-optical deep-space
surveillance system.
geographical envelope protection Database which
prevents the aircraft in which it is installed from entering
a defined keep-out zone, eg overriding pilot’s attempt to
steer into a building.
geographical mile One minute of arc at Equator, defined
as 6,087.08 ft.
geographical position Where line from centre of Earth to
a heavenly body cuts Earth’s surface (astronav).
geographic information system Inputs land use in Gems
(2), and other studies of airport noise.
geographic poles North or south points of intersection of
geosphere
Earth’s surface with axis of rotation, where all meridians
meet.
geoid Earth as defined by that geopotential surface
which most nearly coincides with MSL.
geolocation Finding where fixed targets are on the land
surface, if possible near-instantaneously.
geomagnetic cavity Volume moving through solar wind
occupied by Earth and surrounding magnetic field
(magnetosphere).
geomagnetic co-ordinates System of spherical co-ordinates
based on best fit of centred dipole to actual
terrestrial magnetic field.
geomagnetic dipole Hypothetical magnetic dipole (bar
magnet) located within Earth in such position as to give
rise to actual terrestrial field.
geomagnetic equator Terrestrial great circle everywhere
90° from geomagnetic poles (should not be confused with
magnetic equator).
geomagnetic poles North and south antipodal points
marking intersection of Earth’s surface with extended axis
of geomagnetic dipole; north ** is 78½°N, 69°W, and
south ** is 78½°S, 111°E. Should not be confused with
magnetic pole.
geomagnetism 1 Magnetic phenomena exhibited by
Earth and surrounding interplanetary space.
2 Study of magnetic field of Earth.
geometric dilution of precision See dilution of precision.
geometric pitch Distance propeller-blade element would
advance in one revolution when moving along helix to
which line defining blade angle of that element is tangential;
** of fixed-pitch propeller at standard radius is pitch
of that propeller, and is marked on it.
geometric transition absorber Family of RAM (2) structures,
most common being pyramidal type. Others include
cones and sine waves.
geometric twist Variation along span of aerofoil of angle
between chord and a fixed datum (see aerodynamic twist).
geometry-limited Restriction placed on aircraft attitude
or configuration by geometric considerations; eg scraping
tail on take-off or (variable-geometry aircraft) underwing
stores fouling tailplane at max sweep.
geophones 1 Sensitive acoustic sensors for detecting
sound transmitted through Earth’s crust.
2 Seismic sensors buried along edge of runway to
measure point of touchdown, severity of impact and
bounces on landing (see ALMS).
geopotential altitude
R e H
Z = –––––– where R e = Earth
radius and H is geometric altitude [Z can be ignored at low
altitude].
geopotential height Height above Earth in units proportional
to potential energy of unit mass (geopotential)
relative to sea level. For most meteorological purposes
same as geometric height, but geopotential metre = 0.98
metre; ** used under WMO convention for all aerological
reports.
Georef World Geographic Reference System.
George Automatic pilot (colloq., arch.).
GEOS Geodynamic experimental ocean satellite[s]
(NASA).
GeoSAR Geographic synthetic-aperture radar
(NIMA).
geosphere Solid and liquid portions of Earth’s lithos-
293