1Dk4eXg

X
X 1 Longitudinal axis (more strictly OX); all measurements
parallel to this direction, esp. force; or a distance
along a streamline.
2 Usual symbol for reactance.
3 US DoD aircraft designation mission prefix:
research; and also modified-mission prefix: experimental.
4 JETDS code: (1) identification, recognition;
(2) facsimile, TV.
5 Length of beam or other structural member.
6 IFR flight plan code; transponder, no code.
7 On request.
8 Closed or abandoned.
9 Ground-to-air visual code: require medical aid.
10 Weather: intense.
11 Sky obscured.
12 On request.
13 Prefix, piston engine with one crankshaft driven by
four cylinders, or banks of cylinders, in form of X when
viewed from front.
14 Generalized prefix: expendable.
15 Helicopter rotor side force.
x 1 Generalized term for unknown quantity.
2 Horizontal axis (abscissa) of cartesian coordinates or
graphical figure.
3 Any value measured parallel to (2) or any coordinate
point measured along that axis; in particular distance
along OX axis from helicopter c.g. to intersection with
thrust vector of main rotor.
4 Reactance (X is more common).
5 Longitudinal displacement; distances measured along
OX axis.
6 Mole fraction.
X 1 Forward extent of VTO ground vortex.
X -- Chordwise distance from apex to centroid of wing
area.
x¯ 1 Position of c.g. as co-ordinate along OX axis.
2 Average of several values of x.
/ Wind axis, aligned with direction of flight.
// Fore/aft axis relative to Earth or space.
X-25 Istel communications network allowing dial-up
access to 9.6 kb/s.
X-aerial Crossed rods, two longer (dipoles) and two
shorter (director).
X-allocation First 126 paired (1–63, 64–126) DME interrogation
frequencies [see X-channel].
X-axis X (1) or x (2).
X-band Former common-usage radar frequency band
centred on wavelength of 3 cm, later amended to
2.73–5.77 cm (about 10.9–5.2 GHz), see Appendix 2.
x-bar Crossbar.
X-box generation Today’s young, who from early childhood
have been familiar with computers and [flight]
simulators.
X-C Cross-country.
X-channel DME or Tacan channel associated or paired
with another radio service on same frequency. There are
126, of which first 63 have ground/air 63 MHz below
air/ground frequency and second 63 have ground/air
63 MHz above air/ground frequency.
X-Cty Cross-country; XC, X-C also common.
X-cut crystal Cut parallel to Z-axis, perpendicular to
X-axis.
X-engine See X(13).
X-Geräte Pioneer beam-riding aid to navigation and
bombing (G, WW2).
X-glider Expendable glider (ASW).
X-licences Range of licences for ground engineers, with
endorsements for many disciplines and equipments (UK).
X-plates Vertically parallel deflection plates in CRT
whose potential difference deflects beam horizontally and
creates timebase.
X-ray Extremely short-wavelength EM radiation, with
frequency higher than any other except gamma and
nuclear radiations; typical wavelengths 10–1,000 pm.
X-ray analysis Based on diffraction of X-rays by crystalline
solids.
X-ray astronomy Study of X-rays arriving at Earth from
space (not possible at surface of Earth because of attenuation
by atmosphere).
X-unit Non-SI unit of length = 10 -13 m, = 10 –11 cm = 0.1
pm = 100 fm.
X-wing Aircraft able to operate as helicopter or, with
special [usually four-blade] rotor stopped with blades
diagonal to airstream, as aeroplane. Studied by NASA
1969–.
XA 1 Extended architecture, giving (for example) relief
from storage and I/O constraints.
2 ARINC code.
XB IATA code.
Xbar, XBAR Crossbar (ICAO style).
XC Cross-country.
X c Capacitive reactance.
XCP Except.
X/C Percentage of aerofoil chord.
XCSRA Cross-Channel Special Rules Area (UK).
XCTR Exciter.
XCVR, Xcvr Transceiver.
X/d Distance along jet as multiple of diameter.
XDM Experimental development model.
XDR 1 Extended [ie, high] data-rate.
2 External data representation.
xducer Transducer.
Xe Xenon.
xenon Xe, inert gas, density 5.9 gl –1 , BPt 107°C, used
in lasers and gas-discharge tubes; best fuel for ion propulsion.
xfer Transfer.
xfmr Transformer.
XFR, xfr Transfer.
XFSS Auxiliary flight-service station.
XFV Exo-skeletor flying vehicle.
XG Centre of gravity (c.g. is preferred).
XGA Extra graphics array, 1,024 × 768 pixels.
XI Central office for warfighting integration (USAF).
x i Chordwise position of a vertical web where i is web
number 1, 2, 3 . . .
XID Exchange identification.
XIPS Xenon-ion propulsion system.
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