1Dk4eXg

cross-deck
cross-deck Operations by two or more aircraft carriers,
not necessarily of same navy, in which aircraft operate
from unfamiliar decks on exchange basis; hence * ing.
cross-drive Facility enabling an engine to drive a
secondary power item on the other side of the aircraft
centreline, e.g. left engine to drive right hydraulic pump.
crossed controls Application of flight-control movements
in opposite sense to those in normal turns or
manoeuvres, eg right stick and left rudder; rarely required.
crossed-spring balance Wind-tunnel balance whose
pivots are made up of two or more leaf springs crossing
diagonally and giving virtually frictionless flexure
through defined axes.
cross-fall Transverse slope of runway surface, to ensure
sufficiently quick run-off of water to avoid aquaplaning
except in particular adverse crosswinds.
cross-feed 1 Feeding items (eg, engines) on one side of
aircraft from supply (eg, fuel) on opposite side; abnormal
condition under pilot control.
2 Often crossfeed, use of rudder to minimise sideslip in
roll or in sustained very steep turn. See next.
crossfeed phasing parameter Not quantifiable-value µ
derived from ratios of transfer-function numerators of
rudder: sideslip and aileron: sideslip, with profound effect
on pilot rating.
cross-flow Having two fluids flowing past each other at
90° while separated by thin metal walls.
cross-level Lateral clinometer, instrument formerly
used to indicate direction of local vertical as aircraft
manoeuvres in rolling plane.
cross-modulation Unwanted modulation from one
carrier being impressed on another in same receiver,
usually resulting from inability to filter out certain sidebands.
cross-needle Instrument display based on two pivoted
needles which pilot attempts to keep crossed at 90° in
centre of display.
cross-over exhaust Gas from inboard cylinders of multipiston
engine aircraft is piped to discharge on outboard
side to reduce noise in fuselage.
cross-over model That model of compensatory operation
in a powered flight-control system at which the
open-loop frequency response has a gain of unity, the
same as the closed-loop bandwidth Ω c , i.e. at which openloop
amplitude response crosses 1.0 [zero db] line.
cross-over struts Inclined radial gas paths in one form of
coannular inverted-flow engine to convey high-V core jet
to outer periphery and low-V fan flow to centre.
crossover turn Fighter battle formation in which left
aircraft move across to right.
cross-qualification Among other meanings, qualification
of pilots on a type of aircraft with characteristics and
flight deck similar to that habitually flown, but (except on
simulator) not actually flown; eg, A300B/A310,
B737-300/B757.
cross-radial navigation Routeing not on a radial constituting
a promulgated airway; ie, RNav using VOR and/or
DME to fly direct from A to B (see GNav).
cross-range Approximately at 90° to axis of missile or
space launch range. See next.
cross-range limit Maximum lateral distance to either
side of re-entry trajectory which can be reached by a lifting
body on a particular re-entry.
CRPMD
cross-section 1 Transverse section through object, eg
fuselage or structural member.
2 Measure of radar reflectivity of object, usually
expressed as area of perfect isotropic reflector perpendicular
to incident radiation; depends on structural
materials, incident angles, physical size of target, radar
wavelength and possibly other factors.
3 In nuclear or atomic reactions, area (expressed in
barn) giving measure of probability of process occurring.
cross-servicing Between-flights routine maintenance
and replenishment of aircraft at base of different armed
force or different nation; * guide is manual facilitating
operational turnround at locations where relevant documents
are not available.
cross start Using power from one engine [electrical, air
bleed or whatever] to start another.
crosstalk Unwanted signals generated in one set of
circuits in communications or EDP (1) system by traffic
in another.
cross-trail Distance bomb or other free-fall object falls
downwind measured perpendicular to track (or track at
release point projected ahead).
cross-trail angle Angle in horizontal plane measured at
release point between track and line to point of bomb
impact.
crosstube Transverse tube forming main spar of wing in
most microlight and similar aircraft.
cross-turn Rapid 180° in which each half of formation
turns towards remainder.
crosswind One blowing more or less at right angles to
track, to runway direction, or to other flown direction.
crosswind axis Straight line through c.g. perpendicular
to lift and drag axes.
crosswind component Velocity of wind component at 90°
to runway, track or other direction; = WV sin A where A
is angle between WV and direction concerned.
crosswind force Component along crosswind axis of
resultant force due to relative wind; normally zero except
in sideslip.
crosswind landing gear One whose wheels can be
castored or prealigned with runway while aircraft crabs
on to ground with wings level.
crosswind leg In landing circuit, that made at 90° to
landing direction from end of downwind leg to start of
approach.
crosswind testing Testing of engine with high-velocity
wind (simulated at known speed) blowing across inlet.
crowbar Unswept wing (c 1950 colloq.).
crowd-line Often one word, line defining front edge of
airshow crowd, parallel to runway.
crown 1 Upper part of fuselage, above cabin ceiling, of
passenger transport, especially large pressurized aircraft.
2 Loosely, upper part of any fuselage.
3 Top of canopy [envelope] of balloon.
CRP 1 Carbon-fibre reinforced plastics.
2 Control and reporting point (or post).
3 Counter-rotation propfan.
4 Compulsory reporting point.
5 Contractor’s Repair Party.
CRPA Controlled reception-pattern antenna.
CRPAE Cercle des Relations Publiques de l’Aéronautique
et de l’Espace (F).
CRPM Compressor rpm.
CRPMD Combined radar and projected-map display.
173