1Dk4eXg

TWL
TWL Twin-wheel loading.
TWMS Tactical-weapons management system.
Twng Towering.
TWO Tare-weight objective.
Two, 2 1 The partner in a formation-display duo; his
role is to keep his eyes glued on Lead and position accordingly.
2 Two aircraft in a tactical formation: major variations
are finger 2, fluid 2, deuce, loose deuce, pair, Rotte.
2½-axis machining Continuous-path machining (invariably
with NC) on x, y axes, usually intermittent on z.
two-axis autopilot Simple autopilot having authority in
roll and yaw only.
two-axis homing head Scans in az and el.
two-bay biplane One with wing assembly comprising
two bays on each side of fuselage, each comprising
rectangular cellule of inner and outer interplane struts
with points of attachment linked by diagonal wires.
Loosely, biplane with interplane struts at two different
spanwise locations on each side of fuselage (discounting
any struts near fuselage).
two-colour pyrometer High temperature is measured at
two wavelengths.
two-control aircraft Aeroplane or glider with flightcontrol
system in two axes only, invariably ailerons and
elevator; thus no rudder or pedals.
two-crew Misnomer; what is meant is that flight crew
comprises two persons; * operation is often matter
between airline employers and ALPA, and largest transports
frequently have flight crew of at least three.
two-cycle See two-stroke.
2-D 1 Two-dimensional.
2 Position defined by lateral guidance only in Satnav.
2-DCD Two-dimensional convergent/divergent
(nozzle).
2-D flow Flow which can be described completely in one
plane, eg around wing of infinite span.
two-dimensional matrix Code for marking parts for
identification, small area containing 100 times more information
than bar code.
2-D inlet Two-dimensional inlets are in theory ideal for
operation over wide range of Mach numbers but because
of end and corner effects and mechanical complexity are
in practice inferior to axi-symmetric.
2-DM Two-dimensional matrix.
2-D nozzle Jet nozzle of rectangular cross-section and
constant longitudinal profile which can vector thrust in
vertical plane. Studied for future US fighters. Also called
platypus.
2 DOF Two degrees of freedom.
2-D radar Radar giving target position in two dimensions,
eg az/el, or range/bearing; only a few can pinpoint
body’s location in 3-D space.
2-D wing Usually one of infinite span, whose tip effects
can thus be ignored; for some purposes constant-section
wing joined at each end to tunnel wall is approximation.
twofold flocking Turbofan test for birdstrikes over
whole area of fan and spinner.
two-frequency Glidepath and/or localizer having two
unrelated radiation patterns.
2 Gins Two-gimbal INS (colloq.).
2H-2E Hybrid architecture of secondary power systems
comprising two hydraulic and two electrical circuits.
two-inceptor control Fundamental control strategy for
two-stage supercharger
pilot of jet STOVL aircraft in which left hand controls
speed only (including forward acceleration from hover)
and right hand controls flight trajectory (including hover
height).
two-level bridge (jetway) Passenger bridge whose landside
end can be raised or lowered to mate with either
arrival or departure floor level.
2LM Second-level maintenance.
two-man rule Philosophy under which no individual is
allowed unaccompanied access to NW or certain designated
components or associated system interfaces.
two-meal service Two meals served on one sector.
2-minute turn Rate 1 turn; also called standard turn or
procedure turn.
two-moment equation Relates simple-beam loading to
shear and BM.
2 on 1 injector Rocket liquid injector spraying two
streams of liquid A on to one stream of liquid B, the three
meeting at various angles depending on design.
2-place Two-seater.
2.5-D Describes advanced synthetic vision systems
which give important information on 3-D shapes.
2.5-engine aircraft Twin-engine aircraft certificated to
use APU [or other centreline auxiliary engine] to give
propulsive thrust, especially at takeoff.
2-point landing See wheeler.
2-point suspension Bifilar, hung from two points at same
level on two filaments or cables.
two-point tanker Fitted with two HDUs which can be
used simultaneously.
2-pole switch Opens or closes both sides of same circuit
or two separate circuits simultaneously.
two-position propeller One having only two settings, fine
and coarse.
two-pulse rocket Motor, usually solid propellant,
comprising two stages (eg, boost and sustain fired in
series).
two-rate oleo Normally, first part of travel is at low rate
(ie, large deflection per unit load); after loading to given
limit, often close to static position at gross weight, highrate
law applies. Common on naval helicopters.
two-tow radial See twin-row engine.
two-segment approach Two angles, usually 6°/3°.
two-shaft engine Gas turbine with mechanically independent
LP and HP sections each running at its own
speed, or a free-turbine turboshaft or turboprop.
two-speed supercharger Driven by step-up gearbox
which, usually automatically at given pressure height,
changes ratio to increase impeller speed at high altitudes.
two-spool Gas turbine of two-shaft type, originally
confined to engines having two axial compressors (LP and
HP) in series. Also called split-compressor engine.
two-stage Adjective, achieved in two parts. A turboprop
may have a * compressor through the parts of which the
air flows consecutively, whereas the propeller is driven by
a * gearbox in which both stages operate simultaneously.
two-stage amber Synthetic day/night pilot training aid in
which pilot wears blue goggles and flies trainer with amber
transparencies (or vice versa) which effectively eliminates
external cues while allowing view of instruments.
two-stage igniter Generally, one that first ignites a local
flame, burning main fuel, which in turn is used to ignite
main combustion (gas turbine or rocket but now rare).
two-stage supercharger One having two impellers in
730