1Dk4eXg

BDTF
3 Bypass-duct splitter.
BDTF Bomber Defence Training Flight (RAF).
BDX Beacon-data extractor, or extraction.
BE Business engineering.
Be Beryllium.
BEA 1 British European Airways 1946–72.
2 Bureau Enquêtes Accidents (F).
BEAB British Electrotechnical Approvals Board.
beaching Pulling marine aircraft up sloping beach, out
of water to position above high tide.
beaching gear Wheels or complete chassis designed to be
attached to marine aircraft in water to facilitate beaching
and handling on land.
beacon 1 System of visual lights marking fixed feature
on ground (see aeronautical light).
2 Radio navaid (see fan marker, homing beacon, NDB,
LFM, marker beacon, Z marker).
3 Radar transceiver which automatically interrogates
airborne transponders (see radar beacon, ATCRBS).
4 Portable radio transmitter, with or without radar
reflector or signature enhancement, for assisting location
of object on ground (see crash locator beacon, personnel
locator beacon).
beacon buoy Self-contained radio beacon carried in
emergency kit. Floats on water.
beacon characteristic Repeated time-variant code of
some visual light beacons, esp. aerodrome beacons emitting
Morse letters identifying airfield.
beacon delay Time elapsed between receipt of signal by
beacon of transponder type (eg, in DME) and its
response.
beacon identification light Visual light, emitting characteristic
signal, placed near visual light beacon (pre-1950)
to identify it.
beacon skipping Fault condition, due to technical or
natural causes, in which interrogator beacon fails to
receive full transponder pulse train.
beacon stealing Interference by one radar resulting in
loss of tracking of aerial target by another.
beacon tracking Tracking of aerial target by radar
beacon, esp. with assistance from transponder carried by
target.
bead 1 Corrugation or other linear discontinuity rolled
or pressed into sheet to stiffen it.
2 Thickened edge to pneumatic tyre shaped to mate
with wheel rim and usually containing steel or other
filament reinforcement.
3 Unwanted blob of weld metal.
braded See bead 1
beading Rolling or pressing sheet to incorporate beads.
beadseat Profiled seating on wheel for bead (2), hence *
life, on expiry of which wheel must be reprofiled.
bead sight Ring and bead sight.
Be/Al Beryllium-aluminium.
beam 1 Structural member, long in relation to height
and width and supported at either or both ends, designed
to carry shear loads and bending moments.
2 Quasi-unidirectional flow of EM radiation.
3 Quasi-unidirectional flow of electrons of particles,
with or without focusing to point.
4 Loosely, on either side of aircraft; specif. direction
from 45° to 135° on either side measured from aircraft
longitudinal axis and extending undefined angle above
and below horizontal. Hence, * guns (firing on either
bearing
side), or surface object described as ‘on the port *’ (90° on
left side).
BEAMA British Electrical and Allied Manufacturers’
Association [London SE1 7SL] (UK).
beam approach Early landing systems in which final
approach was directed by beam (2) from ground radio aid
(see BABS, ILS, SBA).
beam attack Interception terminating at crossing angle
between 45° and 135°.
beam bracketing Flying aircraft alternately on each side
of equisignal zone of radio range or similar two-lobe
beam.
beam capture To fly aircraft to intercept asymptotically
a beam (2), esp. ILS localizer and glide path.
beam compass 1 Drawing instrument based on beam
parallel to drawing plane having centre point and carrier
for pen or other marker.
2 Panel instrument providing radio and magnetic
heading information.
beam direction In stress analysis, direction parallel to
both plane of spar web, or other loadbearing member, and
aircraft plane of symmetry.
beam-index display Full-colour CRT using single gun
and no shadow mask, computer switching to illuminate
spots of red, blue or green phosphor according to instantaneous
beam position.
beam jitter Continuous oscillation of radar beam
through small conical angle due to mechanical motion
and distortion of aerial.
beam rider Missile or other projectile equipped with
beam-rider guidance.
beam-rider guidance Radar guidance system in which
vehicle being guided continuously senses, and corrects for,
deviation from centre of coded radar or laser beam which
is usually locked on to target. Accuracy degrades with
distance from emitter.
BEAMS British Emergency Air Medical Service.
beam slenderness ratio Length of structural beam
divided by depth (essentially, divided by transverse direction
parallel to major applied load).
beam softening Progressive reduction in gain of ILS
demand signal.
beamwidth Angle in degrees subtended at aerial
[antenna] between limiting directions at which power
[DoD states “RF power”, NATO states “emission
power”] of radar beam has fallen to half that on axis.
Often defined for azimuth and elevation. Symbol Θ.
Determines discrimination.
bean counting Notional procedure of accountants
whose sole interest is the balance sheet.
beany hat Soft brimmed hat, favoured by glider pilots.
Bear Electronic-warfare officer, usually in defencesuppression
aircraft.
beard radiator piston engine radiator mounted under
the engine.
bearer Secondary structure supporting removable part
such as fuel tank or engine.
bearing 1 Angular direction of distant point measured
in horizontal plane relative to reference direction.
2 Angular direction of distant point measured in
degrees clockwise from local meridian, or other nominated
reference. Such measure must be compass, magnetic
or true. True * is same as azimuth angle.
3 Mechanical arrangement for transmitting loads
92