The Cambridge Aerospace Dictionary Episode 10 pptx

tactical air co-ordinator Directs, from aircraft, air close
support of surface forces.
tactical aircraft shelter Normally protects against
conventional attack but may be extended to offer protec-
tion against NW blast, radiation and CBW.
tactical air officer (afloat) Responsible under
amphibious task-force commander for all supporting air
operations until control is passed ashore.
tactical bomb line See bomb line.
tactical code Two-digit number in various colours on
combat aircraft (R, CIS).
tactical finish Camouflaged: can be all one colour.
tactical input segment Subsystem for receiving EO and
IR images in real time.
tactical intervention vehicle Designed to rescue hostages
from parked aircraft.
tactical laser weapon system An array of mirrors aim
powerful laser simultaneously at multiple munitions.
tactical targeting network technologies Creates networks
between airborne platforms passing data at ȅ 2 Mbit/s
over distances ȅ 100 nm, 185.3 km (USAF).
Tactifs Tactical integrated flight system.
tactile faceplate Electronic display screen sensitive to
fingertip touch for reprogramming, selecting from menu,
changing scale or operating mode, or adjusting any
variable.
tactile situational awareness system A high-tech aircrew
vest.
Tacts Tactical aircrew combat training system (ACMI).
TAD 1 Turbo-alternator drive.
2 Target assembly data.

3 Technology availability date (or data).
4 Towed aerial decoy.
5 Theater, or tactical, air defense.
6 Trim-aid device.
7 Target acquisition and designation.
8 Terrain-awareness display.
TADC Tactical air direction center.
Tadds Target alert data display sets; part of FAAR.
tadec, TADEC Totally automatic digital engine control
[piston engines].
Tadil 1 Tactical digital intelligence, or information, link
(C adds command, J adds joint [service]).
2 Tactical aircraft digital information link.
TADIRCM Tactical aircraft directional, or directable,
IRCM.
TADIXS-B Tactical data information exchange system
– broadcast.
Tadjet Transport, airdrop, jettison.
TADMS TR-1 Asars-2 data manipulation system.
Tadoc Transportable, or tactical, air-defense operations
center, possible confusion with Tradoc.
tadpole Track of moving target on radar display
presented with comet-like tail to show direction of travel.
Most air-defence radars can select tadpoles on or off.
tadpole profile Aerodynamic profile with conventional
nose followed by single-surface construction downstream
(eg fin of A-4 followed by single-skin rudder).
TADS, Tads 1 Tactical air defense sight (US).
2 Towed angular deception system.
3 Target acquisition and designation sight, /PNVS adds

pilot’s night-vision system.
4 Target airborne data system.
5 Tactical laser and designation system.
TAE Thrust-augmented entomopter.
TAEL Turning-area edge light[s].
TAEM Terminal-area energy management.
TAERS Tactical aircrew eye respiratory system.
TAF 1
Tactical air force.
2 Terminal area , or aerodrome, forecast (international
meteorological figure-code).
3 Thermal acoustic fatigue.
TAFI Turn-around fault isolation.
TAFIIS TAF (1) integrated information system.
Tafim Technical architecture framework for informa-
tion management.
TAFS Airfield meteorological forecast.
Tafseg Tactical air force systems engineering group.
TAG 1 Telegraphist/air gunner (Royal Navy, WW2).
2 Thrust-alleviated gyroscope.
3 Tactical Airlift Group (USAF).
4 Telescoped-ammunition gun.
5 Transport Air Group (USMC).
6 Tailored air group.
7 Target-adaptive guidance.
8 Towed acoustic generator.
9 Technical Advisory Group (USAF).
10 Test analysis guide.
Taggart Sometimes rendered Taggent, a tagging agent
incorporated in a strike weapon and released on detona-

tion for detecting and tracking biological aerosols.
TAG Telegraphist/air gunner.
tagging Attaching unmissable warning notice during
maintenance to point out, e.g., that item has been
switched off or disabled.
Tags Technology for automated generation of systems.
Tagwes Target weapons effects simulation, or simu-
lator.
TAH Transfer and hold.
TA/H Twin altitude/height.
TAI 1 Total active inventory.
2 Thermal anti-icing.
TAIC Transport Accident Investigation Commission
(NZ).
tail 1 Rear part of aircraft, where applicable.
2 Assembly of aerofoils whose main purpose is stability
and control, normally located at rear of aerodyne or
airship.
3 Trailing luminous area behind blip of moving target.
4 Normal verb meaning in air-intercept shadowing
from astern.
tail boom Tubular cantilever(s) carrying tail (2) attached
either above short fuselage nacelle or as L/R pair to wings.
tail bumper Projecting or reinforced structure under tail
designed to withstand impacts and scraping on runway.
tail chute See tail parachute.
tailcone Conical fairing of rear of body, esp. down-
stream of turbine disc in jetpipe.
tail damping power factor Numerically the product of
TDR [see next] and URVC.

tail damping ratio A [suggested limited] measure of anti-
spin quality based on side area under tailplane multiplied
by distance to c.g.
tail drag Restraining mass free to slide on ground to
which moored airship stern is attached.
taildragger Aircraft with tailwheel or tailskid (colloq.).
tailed delta Aircraft with delta wing and horizontal tail.
tactical air co-ordinator tailed delta
621
tail-end Charlie 1 Formation of aircraft in single line,
each behind the other.
2 Last aircraft in such a line.
3 Rear gunner in tail of large aircraft (1935–50).
taileron Single-piece horizontal tail surface, one of two
forming tailplane whose left/right halves can operate in
unison (as tailplane commanding pitch) or differentially
(as ailerons commanding roll). Term preferable to
ailevator or rolling tailplane. Elevon differs in that it is
hinged to wing. US term stabilator is ambiguous and can
mean * or slab tailplane.
tailets Small fixed fins on underside of tailplane near
each tip.
tailfeathers Free-floating flaps forming periphery of
supersonic airbreathing propulsive nozzle, usually as
outer boundary of large secondary nozzle. These take up
slipstreaming angular positions aligned with streamlines.
tail fin Fixed stabilizing fin at rear, ‘tail’ normally being
redundant.
tail-first Aerodyne configuration in which the only
auxiliary horizontal surface is ahead of the wing,

commonly called a foreplane or canard.
tail float Float supporting tail of float seaplane (now
arch.).
tail group Complete tail (2), considered as design task or
as element of total aircraft mass.
tail guy Secures tail of moored airship, often to tail drag.
tailheaviness Condition in which aircraft rotates nose-
up unless prevented.
tailhook 1 CTOL by carrier aircraft.
2 Naval pilot (colloq.).
tailless aircraft Normally applied to aeroplanes and
gliders only and usually meaning that there is no separate
horizontal stabilizing or control surface, though there
may be a vertical tail (2). In extreme case there is no tail
surface, and (esp. if fuselage vestigial or absent) this is
more often called flying-wing aircraft).
tail load Vertical up or down thrust acting on tailplane.
tail logo Bold logo of operator displayed on tail; hence
** light, also valuable as anti-collision beacon.
tail number See serial (2).
tailored fuel Synthesized to meet specific operational
specification.
tail parachute Parachute attached to tail, normally for
anti-spin or anti-superstall purpose. Not used as braking
parachute.
tailpipe Exhaust pipe of turboprop or turboshaft;
according to some, piston engine exhaust pipe down-
stream of collector or manifold.
tailplane 1 More or less horizontal aerofoil at tail of
aerodyne (invariably fixed-wing) providing stability in

pitch; fixed or adjustable only for trim, and carrying
elevators (US = stabilizer).
2 Aerofoil pivoted at tail about horizontal axis and
driven directly by pilot of fixed-wing aerodyne or rotor-
craft as primary flight control in pitch in translational
flight; forms complete surface without separate elevators
(US = stabilizer).
tailplane tank Fuel tank, invariably integral, in hori-
zontal tail, to increase system capacity and, esp., to
control longitudinal trim without drag.
tail rotor Helicopter anti-torque rotor, rotating at tail
about more or less horizontal axis. Not used for rear
tandem rotor.
tail setting angle The acute angle between chord lines of
wing and tailplane (1).
tailsitter VTOL aerodyne whose fuselage is approxi-
mately perpendicular at takeoff, in hovering mode and at
landing, today preferably called Vatol.
tailskid Projection supporting tail of aerodyne on
ground, esp. one whose c.g. is well aft of main landing
gear.
tailskid shoe Replaceable pad on end of tailskid which
slides on ground.
tailslide Transient flight condition of fixed-wing aero-
dyne in which relative wind is from astern, eg in stall from
near-vertical climbing attitude.
tailspin Spin (arch.).
tailstander Tailsitter.
tailstrike Scraping rear fuselage on runway on rotation.
Hence, * indicator, frangible foil which causes a bright

flash on EICAS.
tailstrike protection Any of several systems which
prevent a tailstrike, usually by limiting authority of hori-
zontal tail.
tail surface Any aerofoil forming part of tail (2).
tail undercarriage Rearmost unit of tailwheel-type
landing gear (rare, suggest arch.).
tail unit Complete tail (2) of horizontal, vertical and/or
canted surfaces, often including ventral fins or strakes.
Also called empennage.
tail view Tail-on view showing object from directly
astern; not normal aspect for layout drawing.
tailwagging 1 Lateral flexure of fuselage.
2 Flat turns, esp. to steepen glide.
tail warning radar Aft-facing radar, usually of active
type, intended to detect other aircraft (and possibly
SAMs) intercepting from behind.
tailwheel 1 Rear wheel of * type landing gear, suppor-
ting tail on ground.
2 Auxiliary wheel under tail of aircraft with nosewheel-
type landing gear (eg Albemarle); fitted in place of tail
bumper.
tailwheel landing gear Landing gear comprising
left/right main units ahead of c.g. and tailwheel at rear.
tailwind Wind blowing approximately from astern of
aircraft and thus increasing groundspeed.
TAIMS Three-axis inertial measurement system.
TAINS, Tains Tercom and, or Tercom-aided, inertial
navigation system.
TAIR Terminal-area instrumentation radar.

TAIRCW Tactical air control wing.
TAIS 1 Tactical air intelligence systems.
2 Technology application information system (SDI).
3 Tactical airspace integration system.
4 Thermal active intervention system.
Take 5 Traffic crossing airway must maintain
prescribed separation of 5 nm horizontally and 5,000 ft
vertically from any GAT track in airway.
takeoff 1 Procedure in which aerodyne becomes
airborne; not normally used for launch of glider (except
on aerotow) or high-acceleration launch of missile or
RPV, and never for any ballistic vertical-liftoff vehicle. In
author’s opinion verb is best as two words, noun and
adjective as single word without hyphen.
2 Moment or place at which aerodyne leaves ground or
water.
3 Net flightpath from brakes-release to screen height.
tail-end Charlie takeoff
622
4 Power * for extraction of shaft power.
take off To perform a takeoff.
takeoff boost Boost pressure permitted for takeoff,
usually 2 minute limit.
takeoff cone Airspace occupied by aircraft in first
minutes of flight.
takeoff distance, TOD Field length measured from
brake-release to reference zero (at screen); can be longer
than runway and extreme limit TOD
a
= entire runway +

stopway + clearway = TOR
a
× 1.5. For multi-engine aero-
planes usually factored according to number of operative
engines, thus TOD
4
or TOD
3
. TOD
1
= TOD required for
particular aircraft and WAT, not normally to exceed 0.87
TOD
a
.
takeoff distance available Actual distance at particular
time, not necessarily length of runway.
takeoff distance ratio TOD into wind divided by TOD
downwind [with tailwind], usually expressed as
percentage.
takeoff/liftoff area Heliport area, a square with side
equal to main-rotor diameter (FAA).
takeoff limit No general meaning.
takeoff mass Not normal term; for rocket or space
launcher usually liftoff mass or launch mass.
takeoff noise Measured on extended runway centreline
3.5 nm (strictly 6,485.5 m, but taken as 6.5 km) from
brakes-release. A second reference point, not used for
certification, is at side or runway opposite supposed start
of run 1 nm from centreline.

takeoff power Power authorized for piston engine or
turboprop for takeoff, usually 2½-minute rating for
turbine engines. In case of turboshaft, a lower rating than
2½-minute contingency.
takeoff rating 1 Boost/manifold pressure/rpm figures
authorized for piston engine at takeoff.
2 Thrust published for turbojet or turbofan at takeoff,
normally achieved by engine control system rather than
set directly by pilot, and subject to ATR or FTO tech-
niques.
takeoff rocket See rocket-assisted takeoff.
takeoff run 1 Loosely, distance travelled over land or
water in aeroplane or aerotow-glider takeoff to point of
becoming airborne.
2 TOR, field length measured from brake-release to end
of ground run plus one-third of airborne distance to
screen height. TOR
a
= TOR available = length of runway;
TOR
4
, TOR
3
are factored for engine-out cases, and TOR
r
= TOR required.
takeoff safety speed V
2
, lowest speed at which aeroplane
complies with required handling criteria for climb-out

following engine failure at takeoff.
takeoff speed Not defined but loosely = unstick speed.
takeoff thrust Takeoff rating (2).
takeoff weight 1 See MTOW.
2 Actual weight at takeoff (2) on particular occasion.
TAKEOVER In HUD or as caption: autopilot has
disconnected.
T-AKX Ro/Ro ship commandeered in emergency for
RDF.
TAL Transatlantic abort landing (Shuttle).
talbot MKS unit of luminous energy; 1*/s = 1 lm.
TALC Tactical airlift center (USAF).
TALCE Tanker airlift control element (USAF).
TALCM Tactical air-launched cruise missile.
TALD 1 Tactical air-launched decoy [vehicle or
mission].
2 Tactical airborne laser designator.
Taleos Terrain-aided localization using EO sensors.
talkdown Landing, esp. in bad visibility, using GCA.
talk-through Facility whereby two mobile radio stations
communicate via a base station.
tall aircraft One calling for LEW technique or experi-
ence.
tall-aircraft VASI See T-VASI.
Tallboy Armour-piercing bomb, 12,000 lb [5443 kg]
(RAF WW2).
Tallboy torch Turbinlite.
Tally Visual sighting of air-to-air target (RAF).
Tally Ho Air-intercept code: target visually sighted.
Normally followed by Heads Up or Pounce (DoD).

Talon Theater application launch on notice.
Talon(s) Tactical airborne Loran (system).
TALT Tactical arms limitation talks.
TAM Technical acknowledgement message (ICAO).
Tamda Tactical acoustics measurement and decision
aid.
TAMF Training Aircraft Maintenance Facility (DARA
St Athan).
Tammac Tactical airborne, or aircraft, moving-map
capability.
Tamps Tactical automated, or aircraft, mission-
planning system.
Tams 1 Total-airport management system.
2 Transportable automated meteorological station.
T&B Turn and bank.
T&E Test, or trial, and evaluation.
tandem actuator Has two pistons or jacks on same axis,
with linear output.
tandem bicycle gear Two main landing gears on centre-
line.
tandem boost Rocket boost motor(s) mounted directly
behind main vehicle, staging rearwards at burnout.
tandem clapping aerial swimmer Small (the first was
19.5 kg, 43 lb) electrically powered aircraft with four
reverse-cambered aerofoils which clap against each other
in alternate pairs (NRL).
tandem-fan engine Gas turbine with single core driving
front and rear fans on common shaft projecting ahead of
engine; fans can have shared inlet for conventional flight
or valved separate inlet and exits for V/STOL.

tandem main gears Two or more similar main gears in
tandem on left and on right, as on C-5 or C-17.
tandem rotors Helicopter lifted by two (usually identical
but handed) rotors, designated front and rear.
tandem seating One behind the other, in combat aircraft
usually with rear seat at higher level.
tandem vehicle One assembled from portions, eg stages,
assembled in tandem and staged axially, in contrast to
strap-on, lateral or other configuration such as Space
Shuttle.
tandem-wheel gear Two or more similar wheels in
tandem on one leg, ie not a bogie.
tandem-wing aircraft One lifted by two wings in tandem,
neither bearing more than 80% of total weight.
T&M Time and material [contract].
T&O Training and operations.
T&R Training and Readiness (USN).
T&S Turn and slip.
take off T&S
623
Tanegashima Principal Japanese satellite launch
facility.
tangential ellipse See Hohmann.
tangential landing Running landing by rotorcraft or
VTOL.
tangent modulus Slope of tangent to stress/strain curve
at any point.
tangent of camber In aerofoil profile, line drawn tangent
to mean camber line at intersection with leading edge, in
modern wings occasionally negative (sloping up to front).

TANGO, Tango Technology application to the near-
term business goals and objectives, 34 partners in 12
countries with part-EU funding.
Tango 1 Standard ground position marker in shape of T
(RAF).
2 Turbulent (Airmet advisory).
tank Container of all fuel, liquid, propellant, lube oil,
hydraulic fluid, anti-icing fluid or toilet chemical, and
often gun ammunition; not used for containers of
breathing Lox, air-conditioning refrigerants, potable
water or supressant/extinguishant.
tankage Aggregate capacity of all tanks for particular
fluid.
tank circuit Tuned RF circuit with capacitor and
inductor in parallel.
tanker Aircraft equipped for inflight refuelling of
others.
tank farm Cluster of storage tanks, usually for fuel, at
airport.
tank pump Booster pump.
tank sealer Various thermoplastic liquids, resistant to
hydrocarbon fuels, sloshed inside integral tankage to seal
all interior surface; today superior methods of wet
assembly and multiple coatings are used.
tank vent Vent (1).
Tans, TANS Tactical air navigation system; airborne
computer storing many waypoints and fed by other inputs
(eg Doppler, magnetic heading).
tantalum Ta, shiny metal, MPt 2,996°C, density 16.7,
important in refractory alloys. A carbide is harder than

diamond.
TAOC Tactical air operations centre (RAF/Army).
TAOM Tactical air operations module.
TAOR Tactical area of responsibility (UK).
TAP 1 Terminal approach procedure.
2 Air-transport regiment (R).
3 Tactical autopilot, or technology.
4 Technical, or technology, assessment programme.
5 Terminal-area productivity.
tap 1 To bleed; hence tapping, pipe for bleed air.
2 To cut threads in drilled hole; also tool for doing this.
3 Electrical power wire connected to main conductor at
point along latter.
4 Engine throttle or power lever (colloq.).
TAPA 3-D antenna pattern analyser (USAF ECM).
Tape Total airport performance and evaluation (Euret).
tape 1 Main meaning in aerospace is as medium for soft-
ware, usually magnetic or punched paper.
2 One form of CF or other reinforced-plastics prepreg,
used for layups or moulding but seldom for filament
winding.
3 Pinked-edge fabric strip used for surface finishing
(surface *).
tape control Automatic control, eg of machine tool, by
tape (1).
tape instrument Cockpit instrument whose presentation
is based on linear tape driven over end spools, usually in
conjunction with fixed and/or movable index pointers or
bars. Usually vertical, as in VSFI.
tapelayer Computer-controlled tool for laying-up

prepreg tape in manufacture of composite parts; auto-
matically positions, starts, stops and dumps material
rejected during prior editing.
tape lay-up The parts produced by the tapelayer.
tape mission Reconnaissance of Elint type in which
digital (eg signal) or digitized pictorial information is
stored on 7-track magnetic tape from which whole
mission profile can be assigned to exact ground track,
with each hostile emitter or other target assigned to
precise location and timing.
Taper Turbulent air-pilot environment research
(1960–65 NASA-FAA).
taper For given wing section profile * equal in plan and
thickness, usually defined as straight or compound; in
some aerofoils * not equal in plan/thickness so section
profile changes.
tapered sheet Thickness varies (usually at uniform rate)
along one axis.
taper ratio Normally defined as ratio of tip chord C
t
to
either root chord or equivalent centreline chord C
c
.
taper reamer Used to smooth and true previously
tapped hole.
taper tap Hand-turned tap (2) to initiate thread cutting.
Tapley meter Damped pendulum in heavy stable case
whose limit of swing feeds record of instantaneous or
maximum vehicle deceleration; not suitable for runway

friction measures.
Taps, TAPS 1 Tercom aircraft (or tracking and) posi-
tioning system.
2 Terminal applications processor system.
3 Target analysis and planning system.
4 Twin annular pre-swirl.
taps Throttles (colloq.).
tap test Crude search for delamination or other flaw in
composite structure, typically with a coin.
TAR 1 Terminal-area surveillance radar (ICAO).
2 Terminal approach radar.
3 Thrust auto reduce (SST).
4 Threat-avoidance receiver; passive ECM.
5 Trials ATN router.
6 Test action request.
Tara Terminal and regional airspace.
Tarad Tracking asynchronous radar data.
Taran 1 Tactical attack radar and navigation.
2 Test and repair as necessary.
Taras Tactical [digital] radio system (Sweden).
Tarasov-Bauer Computer-based method of smoothing
out judge’s scores to eliminate highest and lowest (CIVA).
TARC 1 Transport Aircraft Requirements Committee
(UK 1956–62).
2 Tactical air reconnaissance center (USAF).
Tarcap Target combat aircraft practice (practise).
TARE, Tare 1 Tactical air reconnaissance equipment.
2 Telemetry, or telegraph, automatic relay equipment
(NATO).
tare Unladen, without load, crew or fuel; normally used

only in connection with surface vehicles, except for ULDs,
Tanegashima tare
624
where * includes linings and fittings according to specifi-
cation or registered with IATA.
tare effect Forces and moments on tunnel model caused
by support-structure interference.
tare weight allowance Free allowance given by IATA to
shippers for ULDs not owned by members.
TAREWS, Tarews Tactical air reconnaissance and
electronic-warfare support; RPV (USAF).
TARG, Targ Telescoped ammunition revolver gun.
Target Training and rehearsal generation toolkit.
target 1 Objective of air-combat mission, either in air or
on surface.
2 Objective of intelligence or Elint activity.
3 Any true echo (blip) seen or radar, and object causing
it.
4 Objective of any missile.
5 To insert position co-ordinates of fixed surface * into
guidance software of ballistic or cruise missile; also called
targeting.
6 Unpiloted (towed or RPV) aerodyne serving as target
for friendly fire.
7 Aircraft within surveillance range of TCAS.
target acquisition Detection, identification and location
in sufficient detail for effective employment of weapons.
target alert EFIS warning of future turbulence.
target allocation In air-defence weapon assignment,
process of assigning particular target or airspace to partic-

ular interceptor or SAM unit (NESN).
target approach point Navigation checkpoint, usually
prominent land feature similar to initial point, over which
final turn in to DZ or LZ is made.
target CAP Target combat air patrol; patrol of fighters
over enemy target area to destroy hostile aircraft and
cover friendly surface forces.
target capture To detect, identify and locate a target in
flight.
target crossing speed Relative lateral velocity or sight-
line spin (angular rate) or aerial target seen from
interceptor.
target date Date on which particular planned event
should take place.
target designation Marking or otherwise pointing out a
target, or setting it into HUD or fire-control system.
target designation control Throttle thumbswitch for
slewing sight (or HUD) brackets to contain a surface
target.
target director post Positions friendly aircraft, in all
weathers, over predetermined geographical positions, eg
targets.
target discrimination See discrimination.
target dossier File of assembled intelligence information
on target, normally including multisensor readouts and
Elint.
target drone Pilotless target aircraft, today often an
RPV.
target ensemble Region of sky occupied [or expected to
be occupied] by multiple air/ground munitions.

target-following radar One locked on to target.
target indicator, TI Visible pyrotechnic, electronic
homing beacon or other device air-dropped on surface
target.
targeting 1 To target (5).
2 Distribution of targets assigned to weapons, esp. to
ICBMs and SLBMs.
target marker Visible pyrotechnic dropped on surface
target, or aircraft dropping same.
target of opportunity 1 Target visible to a sensor or
observer and within range of weapons and against which
fire has not been scheduled or requested (DoD).
2 Target which appears during combat and which can
be reached by weapons and against which fire has not
been scheduled (NATO).
Note: both the above can be ground or air.
3 NW target detected after operation begins that
should be attacked as soon as possible within time limits
for co-ordination and warning friendly forces.
target pattern Flightpath of aircraft (meaning is
normally in plan view) during attack phase (DoD).
target price That hoped to be achieved, eg in incentive-
type contract.
target recognition Positive identification of type of
target (eg type of aircraft), by visual means or by high-
resolution sensor giving jet modulation or prop/rotor
reflection signature.
target reverser Jet-engine (turbojet or turbofan) thrust
reverser comprising two deflectors (also called clamshells
or buckets) which swing down to meet downstream of

nozzle.
target strength T = E - (S+2H) where S is source, E echo
and H radar transmission loss; unit is dB.
target symbol Computer-generated on display.
target tape Basic software for programming missile
guidance of inertial and certain other species.
target tug Manned aircraft or RPV towing target (6) for
live air/air or surface/air firing.
tarmac Colloq. UK (esp. non-aviation people) for
paved apron; US = hardstand.
Tarmos Tactical radio monitoring system.
Tarms Tactical aerial resource-management study
(aerial firefighting).
TARN Telegraphic auto routing network (NATO,
Litton).
Tarpol Tariff policy.
Tarpos Target positional data [attack on moving
surface target].
Tarps Tactical-aircraft, or air, reconnaissance-pod
system (USN).
TARS, Tars 1 Tethered aerostat radar system.
2 Theatre airborne, or tactical air, reconnaissance
system.
3 Tactical Air Research and Survey Office (USAF,
formerly).
Tarsp Tactical air radar signal processor.
TAS 1 True airspeed.
2 Training aggressor squadron.
3 Target-acquisition system.
4 Typed air station.

5 Thallium arsenic selenide.
6 Tactical acoustic system.
7 Towed-array sonar.
8 Tracking adjunct system (SAM).
9 Targeting avionics system.
10 Traffic-avoidance system (Japan).
11 Tactical Air Squadron (Poland).
12 Transportable aerosat system.
TASA Thai Aero Sport Association.
TASC 1 Touch-activated screen (or simulator) control.
2 Technical and Air Safety Committee of GAPAN.
tare effect TASC
625
TASD Trajectory and signature data.
Tasdac Tactical secure-data communications (USAF).
taser Hand-held NLW which delivers temporarily in-
capacitating shock via probes fired by nitrogen gun.
Tases Tactical airborne signal exploitation system.
Tasets Tactical steerable emitter threat simulator.
Tasi True airspeed indicator (pronounced ‘tarzi’).
task 1 Specific assignment to one air vehicle, or any
other military force, normally involving operational or
simulated mission or particular training exercise or
programme.
2 Specific assignment to competitors in sailplane cham-
pionships, eg speed round triangle, distance or declared
goal, not disclosed prior to day.
tasked Required to fulfil certain tasks (1), either of
variable operational or routine nature. Not available for
other missions.

tasking Process of assigning tasks to available units or
individual aircraft or crews to fulfil all mission require-
ments.
TASM 1 Total available seat-miles.
2 Tactical anti-ship, or air-to-surface, missile.
3 Top-attack submunition.
Tasmo Tactical air support for maritime operations.
TASR 1 Tactical automated situation receiver.
2 Terminal airport surveillance radar.
TASS Tactical Air Support Squadron (USAF).
Tass 1 Tactical automated security system.
2 Towed-array surveillance system.
3 Terminal-area surveillance system (1995 onwards).
TASST Tentative airworthiness standards for [a future]
SST (FAA).
Tasuma Target and surveillance unmanned aircraft.
Tasval Tactical-aircraft survivability against armour;
post-Jaws (USA/USAF).
TAT 1 Total, or true, air temperature.
2 Turnaround time.
3 Tactical aircraft turret (helicopter).
TATC Terminal ATC; A adds automation.
Tatcof Transportable ATC facility.
TATF Terminal Automation Test Facility (FAA).
TATI, Tati Trim and tailplane incidence (indicator)
(pronounced ‘tatty’).
TATP Triacetone triperoxide, high explosive.
TATS 1 Tactical aircraft training system.
2 Tactical Aerial Targets Squadron (USAF).
TAU 1 Target acquisition and tracking unit.

2 Terminal access unit.
3 Threat awareness unit.
TAV 1 Transatmospheric vehicle.
2 Total asset visibility.
TAW 1 Thrust-augmented wing.
2 Terrain-awareness warning.
3 Tactical Airlift Wing.
TAWC Tactical Air Warfare Center.
TAWDS Target-acquisition/weapon-delivery system,
with Pave Mover.
Taws 1 Terrain-awareness [or avoidance] warning
system [previously EGPWS, now e-TAWS].
2 Theater airborne warning system.
tax Taxiway lights (ICAO).
TAXI Taxi and parking facilities airfield chart.
taxi To move aircraft on surface (land or water) under
its own power.
taxi channel Defined path for marine aircraft.
taxi-holding position Designated point at which all
vehicles may be required to hold to provide adequate
clearance for arrivals/departures on runway.
taxiing Participle/gerund from taxi; note spelling.
taxilane Path on large apron or other paved area to be
followed by nose gear, marked by continuous white line.
taxitrack Assigned taxiing route at land airfield, not
necessarily paved. Most or all may be perimeter track.
taxiway Assigned taxiing route at land airfield, paved.
Taylor diagram Plot of dry and saturated adiabatic
curves on axes of pressure and volume (reciprocal of
density) showing loss of pitot pressure in moist air.

Taylor/Maccoll Original more exact solution for pres-
sure over unyawed circular cone in supersonic flow
(1932).
Taylor Maclaurin Mathematical expansion of f(x) for
values near x = 0.
Taylor recorder Automatically counted number of times
a preset vertical acceleration was exceeded (RAE, 1950).
Taylor series Power series of f(x) in ascending powers of
xҀa where f(x) and derivatives are continuous near x = a.
TB 1 Turn/bank.
2 Timebase.
3 Torpedo-bomber (USN, 1935–46).
4 Terminal block.
5 Heavy bomber (USSR).
6 Turbulence.
t
b
Burn time.
TBA 1 Total (helicopter rotor) blade area.
2 Test-bed analysis.
T-bar system See T-VASI.
TBB Transfer-bus breaker.
TBC 1 Toss-bombing computer.
2 Tailored-bloom chaff.
3 Tactical bombing competition.
4 Thermal barrier coating.
TBCC Turbojet-, or turbine-, based combined cycle.
TBCP Telebrief control panel.
TBD 1 To be determined, or decided.
2 Time/bearing display.

3 Trail[ing] blade damage.
TBE Timebase error.
TBH 1 Truck-bed height.
2 Turbine- [or thrust-] bearing housing.
TBI Turn/bank indicator = turn/slip.
TbIG Terbium iron garnet.
TBL Towbar-less, i.e. not fitted with towbar.
TBM 1 Theater battle management; CS adds core
system[s], S system.
2 Tactical, or theater, ballistic missile; D adds defense,
DFS defense feasibility study, EWS early-warning system
(USA).
TBO Time between overhauls.
TBPA Torso back protective armour.
TBR Torpedo-bomber reconnaissance.
TBRP Timebase recurrence period.
TBS 1 To be supplied, or specified.
2 Tailored business stream (DCAC).
TBT 1 Turbine-bearing temperature (also used to mean
turbine temperature).
2 Transonic blowdown tunnel.
TBV Tilt-body vehicle.
TBW Throttle by wire.
TASD TBW
626
tBX Air temperature (USSR, R, Cyrillic characters).
TC 1 Toilet cart.
2 Time constant, or critical [see TCAIA, TCT].
3 Turn (or twin) co-ordinator.
4 Thermocouple.

5 Test-complete (verb).
6 Type, or Technical, or Transport, Certificate (US).
7 Top of climb.
8 Taxiway centreline (lights).
9 Turbocharged.
10 Tropical cyclone, or continental.
11 Top of cylinder.
12 True course.
13 Transport Canada, with many suffixes, including N
(data-processing network) and TSB (technical services
branch).
14 Transformational communications (USAF).
Tc 1 Tropical continental air mass.
2 PN code bit length, also called chip width.
3 Adiabatic flame temperature of rocket.
4 Superconducting critical temperature.
T/C Top of climb.
t/c Thickness/chord ratio of aerofoil.
TCA 1 Terminal control area.
2 Télécommande automatique; IR/optical + wire
guidance for missile. Operator merely keeps sight on
target.
3 Time of closest approach.
4 Track crossing angle.
5 Temperature control amplifier.
6 Technical collaboration agreement.
7 Turbine cooling airflow.
8 Technical, or technology, concept aircraft (SST).
9 Tungsten carbide alloy.
10 Traffic-collision avoidance; D adds device (for GA;

1980s).
11 Throttle-control assembly.
12 Transformational communications architecture.
TCAA 1 Taiwan CAA.
2 Transatlantic Common Aviation Area.
TCAC Tactical Control and Analysis Center.
TCAIA Time-critical automatic identification and
attack.
TCAR Transatlantic collaborative advanced radar.
TCAS 1 Pronounced T-cass, traffic alert and collision-
avoidance system [see entry]; -RA adds resolution
advisory.
2 Tandem clapping aerial swimmer.
TCB 1 Turret control box (helicopter).
2 Trusted computer, or computing, base.
TCBM Transcontinental ballistic missile.
TCC 1 Thermal-control coating.
2 Thrust control computer.
3 Telecommunications center(s).
4 Titanium-coated carbon.
5 Turbine-case cooling.
6 Tactical co-ordination console.
7 Tactical control center.
8 Technical co-ordinating committee.
9 Troop Carrier Command (USAAF, WW2).
10 Temporary Council committee.
TC
3
, TCCC Tower control computer complex; S adds
system.

TCCF 1 Tactical combat control facility (USAF).
2 Technical communication control facility.
TCCP Take-command control panel.
TCD Time-critical data.
TCDD Tower-cab digital display (ATC).
TCDL Tactical common data-link.
TCDS Type Certificate data sheet.
TCEA Training Centre for Experimental Aero-
dynamics (NATO, Brussels).
TCF Terain clearance floor.
tcf Trillion cubic feet.
TCG Troop Carrier Group (USAAF).
TCH 1 Threshold crossing height.
2 See TKP.
TCI 1 Tape-controlled inspection.
2 Time-controlled item.
TCIM Tactical communications interface modem, or
module.
TCIR Toxic-chemical inventory release.
TCJ Tactical communications jamming.
TCL Taxiway centreline light[s].
TCLT Tentative calculated landing time.
TCM 1 Trim-control module.
2 Trellis coded modulation.
3 Throttle clutch motor.
4 Trajectory-correction manoeuvre.
5 Technical co-ordination meeting.
6 Transformational communications milsatcom, or
military [also called TCS, TSAT].
TCMA Time co-ordinated multiple access.

TCML Target co-ordinate map locator.
TCMS Test-content management system.
TCN Tacan.
TCO 1 Total cost of ownership.
2 Tape-controlled oscillator.
3 Tactical Control Officer.
4 Tone cut-off (noise reduction).
TComSS Telephonics communications management
system.
TCP 1 Transfer-of-control point.
2 Transmission control program, or protocol
(Autodin).
3 Tri-cresyl phosphate.
4 Thrust centre position (of gross thrust vector).
5 Takeoff-chart computation program.
TCPA Time to closest point of approach.
TCPED Tasking, collection, processing, exploitation
and dissemination.
TCP/IP TCP (2) internet protocol.
TCQ Throttle control quadrant.
TCR 1 Terrain-closure rate.
2 Thickness/chord ratio.
3 Time-compliance requirements.
TCS 1 Tilt-control switch (tilt-wing V/STOL).
2 TV camera set (F-14).
3 Tracking and communications subsystem (ACMI).
4 Telemetry and command system (satcom).
5 Turbulence-control structure.
6 Tactical-control system, or squadron.
7 Trusted computer system, meeting requirements for

secure access.
8 Tactical-command system.
9 Touch-control steering.
10 Target control set.
11 Total-component support.
tBX TCS
627
12 Troop Carrier Squadron (USAAF).
TC/s Teracycles per second, = THz.
TCSC Titanium-coated silicon carbide.
TCSEC Trusted-computer system evaluation criteria.
TCSS Terminal communications switching system.
TCT 1 Time-critical target, or targeting; A adds aid.
2 Tactical computer terminal.
3 Transverse-current tube.
4 Target-centred tracker.
5 Takeoff configuration test.
6 Turbomachinery and combustion technology.
7 Targeting-cycle timeline = S2S.
TCTO Time-compliant, or compliance, technical order.
TCTT Time-critical target technology.
TCU 1 Tracking control, or and communications, unit.
2 Thermal cueing, or control, unit.
3 Tracking and communication unit (UAV).
4 Take-control unit.
5 Tacan control unit.
6 Telephone conversion unit.
TCU, TCu Towering cumulus.
TCV 1 Total-containment vessel.
2 Terminal-configured vehicle.

TCW 1 Terminal controller workstation.
2 Tactical Communications Wing.
3 Tactics and Countermeasures Wing (RAF AWS).
4 Troop Carrier Wing (USAAF).
TCX Transfer-of-control cancellation message.
TCXO Temperature-controlled crystal oscillator.
TD 1 Target drone (USN category 1942–46).
2 Touchdown.
3 Transposition docking.
4 Time difference, or delay.
5 Tunnel diode.
6 Test directive.
7 Time duplex.
8 Tactical Director (USAF).
9 Tactical display.
10 Thrust decay; S adds system.
T
d
, Td, T–D Dewpoint temperature.
t
d
Ignition delay time of rocket.
T/D Top of descent.
TDA 1 Tunnel-diode amplifier.
2 Temporary danger area.
3 Trade and Development Agency (US).
4 Theater-defense architecture.
5 Today.
TD&E 1 Transposition, docking and LM ejection.
2 Tactics development and evaluation.

TDAP Touchdown aim point.
TDAR Tactical defence alerting radar.
TDAS Test, or tracking and, data acquisition system.
TDATS, T-Dats Target detection, acquisition and
tracking system.
TDC 1 Top dead centre.
2 Through-deck cruiser, for Stovls.
3 Technical Development Center (FAA).
4 Target designator, or designation, control.
TDCP Tactical-data communications processor
(USMC).
TDCS Traffic-data collection system.
TDD 1 Tactical-related data-dissemination system.
2 Target-detection device.
TDE 1 Target-data extractor.
2 Tactical-data equipment.
TDEC Technical Development and Evaluation Center
(CAA Indianapolis from 1939).
TDEFS Technology demonstrator for enhancement
and future systems.
TDEU Test and data-extractor unit.
TDF 1 Tactical digital facsimile.
2 Tactical-display framework (Awacs).
TDG 1 Triggered-discharge gauge.
2 Two-displacement gyro.
TDI 1 Triple-display indicator [fluid pressure, three dial
scales].
2 Tapped delay input.
3 Trade-data interchange, part of Apex.
4 Time-delay and integration (TICM).

5 Time-of-day interface.
TDL 1 Tactical data-link; PS adds processing system.
2 Tactical data-loop; S adds system.
3 Trapped delay-line.
4 Truck dock lift.
TDLS Tower data-link services, such as pre-departure
clearance and D-ATIS.
TDM 1 Time-division, or -domain, multiplex.
2 Tactical-data management, or modem.
TDMA Time-division, or domain, multiple access.
TDMMS Telemetry Doppler metric measurement
system.
TDMS Test-documentation, or tactical-data, manage-
ment system.
TDO Tornado.
TDoA Time-difference, or delay, of arrival.
TDOP Time-dilution of precision.
TDP 1 Touchdown point; D adds dispersion.
2 Target-data panel.
3 Technology-demonstration, or development, pro-
gramme, or project.
4 Three-day planning; F/C adds forecast chart.
TDPF Tail-damping power factor.
TDPS Tracking, or test, data-processing system.
TDR 1 Tail-damping ratio.
2 Takeoff-distance ratio.
3 Technical-despatch reliability.
4 Transponder [XPDR more common].
5 Traffic-data record.
6 Terminal Doppler radar.

TDRE Tracking and data relay experiment.
TDRS 1 Tracking and data-relay satellite; S adds
system.
2 Technology demonstration and [or for] risk-
reduction.
TDS 1 Tactical-data system.
2 Time/distance/speed scale.
3 Tactical Drone Squadron.
4 Thermal diffuse scattering.
5 Training Depot Station (RFC).
6 Target-designation sight.
7 Threat deception system.
8 Threat-detection system; -FA adds fighter aircraft,
-H helicopter.
9 Thrust-decay system.
10 Terminal display system.
TDST Tower data services terminal.
TDT 1 Tactical data terminal.
2 Transonic dynamics tunnel.
TC/s TDT
628
TDTG Twin delta tandem [landing] gear.
TDTS Tactical-data transfer system.
TDU 1 Test, or TV, or terminal, display unit.
2 Torpedo Development Unit (RAF Gosport, 1938,
became ATDU).
TDV 1 Technology development vehicle.
2 Truck dock vehicle (cargo handling).
TDWR Terminal Doppler weather radar.
TDX Target-data extractor.

TDY Temporary duty.
TDZ Touchdown zone; CL adds centreline lighting, E
adds elevation, L lights, M marking.
TDZ marking White axial stripe on each side of runway.
TE, t.e. 1 Trailing edge.
2 Tactical evaluation.
3 Taxiway edge (lighting).
4 Table of equipment.
T/E Twin-engine[d].
Te Tellurium.
TEA 1 Tri-ethyl alcohol, hypergolic igniter.
2 Transferred-electron amplifier.
TEAM, Team 1 Training equipment and maintenance
(NATS).
2 Technology for efficient agile mixed-signal
micro-systems.
teaming agreement 1 Inter-company agreement for
marketing purposes, not involving licensing or co-
production.
2 Now coming to mean any inter-company agreement
to assist penetration of markets.
teaming down Getting into partnership with smaller
companies.
teaming up Getting into partnership with one or more
giant companies, one of which may be eventual prime.
teampack Packaged for carrying across rough terrain by
team of 2 to 8 personnel.
Teams 1 Tactical evaluation and monitoring system
(Northrop).
2 Tactical electronic-aircraft [or EA-6B] mission

support system (USN/USMC).
tearaway connector Umbilical pull-off coupling.
teardown Dismantling into component parts.
teardrop Standard procedure flying pattern similar to
racetrack but with one end having large-radius and the
other small.
teardrop canopy Of smoothly streamlined shape, usually
moulded from one transparent sheet.
tear off a strip To deliver spoken reprimand (RAF,
colloq.).
tearoff cap Lightly sewn fabric parachute cover torn off
pack by static line.
tearstrap Doubler fastened [if possible, bonded] to skin
to arrest progress of tensile crack.
tease Faulty operation of circuit-breaker in which snap-
action is absent; hence *-free.
TEB Tri-ethyl borane.
TEC 1 Trans-Earth coast.
2 Thermal (or thermoelectric) energy converter.
3 Thermoelectric cooler, or cooling.
4 Tower en-route control.
tech Adjective, to go * = unserviceable (colloq.).
TECEVAL Technical evaluation (USN).
tech mod Technology modernization.
Technamation
Technical animation, methods for
training and educational displays giving illusion of
motion, eg flow through pipes, rotation of shafts, etc.
Technical Assistance Agreements Bilateral agreements
permitting disclosure of sensitive items by the US to the

UK, notably concerned with LO technology (10 negoti-
ated by early 2003).
technical delay Delay ascribed to fault in hardware,
lasting longer than 5 (sometimes 15) min.
technical despatch reliability Percentage of scheduled
flights which are unaffected by any prior technical fault,
but ignoring delays due to other causes.
technical electrics All services other than commercial
electrics.
technically closed Problem has been solved.
Technical Standard Order Establishes quality control
for avionics and other equipment; thus TSO’d items bear
higher price (FAA).
technical stop Stop by commercial transport at airport
for reasons other than traffic; not shown in timetable.
technical survey Inspection for monitoring (bugging)
systems (DoD).
Techroll Patented (CSD) configuration for vectoring
nozzle of solid-propellant rocket motor in which nozzle
drive forces are reduced by fluid-filled constant-volume
surround sealed by flexible diaphragm.
Tecmus Tactical ECM upgrade system.
Tecom Test and Evaluation Command (USA, APG).
Tecos Terminal co-ordination system.
TECR Technical reason (ICAO).
Tecstat Nazionale Associazione Tecnici di Stato (I).
TED 1 Transferred-electron device.
2 Tactical (or threat) evaluation display.
3 Trailing edge down, or device[s].
4 Threat-environment description.

5 Tool and equipment drawing.
6 Trace [of] explosives detector.
TEDA Triethylenediamine.
Tedlar Flexible PVF film for surface protection (regis-
tered name).
TEDS Tactical expendable drone system, for ECM
saturation jamming.
TEE Tubular extendible element, produced by un-
rolling steel tape.
tee Air/ground wind-direction indicator in shape of
large T in white, either placed on ground and occasionally
rotated or pivoted to base (and in a few cases moved by
weather-cocking). Cross-piece is at downwind end of
upright.
TE-Ebaps Transferred-electron electron-bombarded
active pixel sensor.
tee connector T-shaped plumbing connector.
Tee Emm Training memoranda [and excellent period-
ical] (RAF).
tee gearbox One rotary shaft geared to another at 90° at
a point other than one end.
tee junction T-shaped connection of two microwave
waveguides.
teetering rotor Helicopter main rotor with two blades
freely pivoted as one unit about horizontal axis transverse
to line joining blade tips.
TEF Total environment facility, for processing recon-
naissance data.
Teflon Trade name (du Pont) for large family of fluoro-
carbon-resin rubbers and plastics.

TDTG Teflon
629
Tefzel Trade name (du Pont) for EPTE products.
TEG 1 Tactical exploitation group (satellites).
2 Thermo-electric generator.
tehp Total equivalent horsepower, normally same as
ehp.
TEI 1 Trans-Earth insertion (or injection).
2 Text-element identifier[s].
3 Thermocouple engine instrument.
tektites Small glassy bodies unrelated to surrounding
Earth surface and believed of extraterrestrial origin.
TEL 1 Tetraethyl lead.
2 Telebrief.
3 Telephonic (ICAO).
4 Transporter/erector/launcher; AR adds and radar.
Telar TEL (4) and radar, on one vehicle.
TELATS Tactical electronic locating and targeting
system (USAF).
telebrief Direct telephone link between ground
personnel, eg air controller or ground crew, and military
aircrew seated in aircraft on ground.
telecommunications Transmission, emission or recep-
tion of signs, signals, writing, images or sounds by wire,
radio, visual or other EM system; abb. telecom.
teleconference Conference between participants linked
by telecom system.
Teleflex Mechanical remote-control systems in which
push/pull commands are transmitted by tube-mounted
cable with complex coiled overlayers [able to drive

toothed wheel].
telegraph Telecom using succession of identical elec-
trical pulses.
teleguided Not a normal expression; could mean a
missile guided by radio command or by wires.
telematics This word does not appear in normal English
dictionaries. It appears to mean automatic control over
wide areas encompassing several systems.
telemetry Transmission of real-time data by radio link,
eg from missile to ground station; today invariably digital
and important in RPVs and unmanned reconnaissance
systems. Data can be pressure, velocity, surface angular
position or any other instrument output, or any form of
reconnaissance output. Telemeter is verb; use as noun
arch. Noun is * system or telemetering system.
teleoperator Robot for performing mechanical tasks
under remote control.
telephone Transmission of sounds, signals or images by
wire or other discrete-path link, eg microwave beam or
optical link using free coherent beam or fibres.
telephone box Figurative enclosure of aircraft whose
energy has decayed in air combat to point where he is low
and slow and has ‘no place to go’.
telephotography Photography of distant objects on
Earth.
telephotometer Visibility meter.
teleprinter Telegraphy with keyed input and printed
written output.
teleprocessing EDP (1) by computer fed by telecom
system.

teleran Television radar air navigation; use of ground
radar to feed airborne TV display.
Telesacs Telematics for safety-critical systems, in par-
ticular co-ordination of ACAS, STCA and precision
navigation (Euret).
telescience Increasing output of space science experi-
ments by use of Internet and broadband satellite commu-
nications to involve ground-based researchers.
telescope 1 In astronomy, instrument for collecting EM
radiation (esp. light, radio, IR and X-ray) from extra-
terrestrial sources.
2 To reduce overall dimensions by folding or, esp.,
linear retraction, eg helicopter rotor.
3 To reduce propeller diameter by cropping tips.
telescoped ammunition Rounds in which the projectile is
carried largely within the case, reducing length and
increasing propellant energy per unit overall volume.
telescope gauge Precision rod sliding in tube and locked
to measured dimension, eg hole diameter, subsequently
measured by micrometer.
telescoping To telescope (2, 3).
telescramble To render telecom, usually telephone,
conversation unintelligible by scrambling.
teletype US term for teleprinter; hence *-writer; often
capital T (registered name).
television Transmission and reception of real-time
imagery by electronic means. Link usually by radio but
may be any other telecom form, and imagery usually
keyed to sound channel, entire received signal also being
recordable by receiver; abb. TV.

television command See television guidance
.
television guidance Command guidance by radio link
sending steering commands from operator watching TV
picture taken by camera in nose of vehicle.
telint Telemetry intelligence.
telling See track telling.
telltale An indicator of position external to cockpit,
such as rods projecting through wing skin to show
landing-gear position.
tellurium Te, semi-metal, density 6.2, MPt 450°C, metal
alloys, glass, ceramics, electronics.
Telops Telemetry on-line processing system.
TELS Turbine-engine loads simulator.
TEM 1 Transmission electron microscope (or
microscopy).
2 Technical error message (ICAO).
3 Thermally expanded metal.
4 Illustrated tool and equipment manual.
T/EMM Thermal and energy-management module.
TEMP, Temp 1 Temperature (ICAO).
2 Temporary.
3 Test and evaluation master plan (AFSC).
temper Degree of hardness introduced to metal by heat
treatment, cold-working or other process.
temperature Property of material systems, commonly
called intensity of heat, determining whether they are in
thermodynamic equilibrium. Normally a measure of
translation kinetic energy of atoms or molecules. SI unit
is K, not necessarily written °K. Specified as reported *, a

local actual value, or as forecast * or declared *, read from
statistical tables.
temperature accountability All factors, in aircraft
design, operation and certification determined by reduc-
tion in propulsive thrust and wing lift caused by increase
in atmospheric temperature.
temperature coefficient Rates of change of variable per
unit change in temperature.
temperature coefficient of pressure For a given ratio of
solid-rocket-motor surface to throat area,
π
k
=
δ
I
n
P
c
/
δ
T
Tefzel temperature coefficient of pressure
630
where I
n
is initial specific impulse, P
c
is chamber pressure
and T is temperature.
temperature correction Correction applied to bring

instrument reading to STP conditions.
temperature gradient Rate of change of temperature
with unit distance through material in direction normal to
isotherm surfaces, esp. rate of change of temperature in
atmosphere with unit increase in height.
temperature inversion See inversion.
temperature lapse rate Lapse rate.
temperature probe Sensor protruding into air-
stream, giving output requiring correction to give static
temperature.
temperature recovery factor Usually, equilibrium
temperature of solid surface in high-speed flow, varying
according to turbulence of boundary layer; usually T
w
and given by several formulae.
temperature shear Rapid change in atmospheric temper-
ature with horizontal or vertical travel [can cause
unacceptable change in Mach whilst holding
airspeed/altitude constant].
temperature stress Stress caused by temperature, esp.
changes in temperature between different parts of mono-
lithic body.
temperature traverse Series of temperature (usually
stagnation/total temperature) measures taken either over
area or along straight line perpendicular to fluid flow, eg
at exit from combustion chamber.
Tempest Transient EMP emanation standard.
template Simple pattern, usually planar, either cut to
shape of a part or with shape and dimensions marked on
surface, used as guide in repeated marking out of desired

shape. In UK occasionally written templet.
Temple-Yarwood Formula for pressure coefficient at
low Mach as function of critical Mach M
c
: C = 1 – 0.522
(1 + 0.2 M
c
2
)
3
/M
c
2
(1 – 0.05 M
c
2
)
2
.
Tempo 1 Technical military planning operation.
2 Also TEMPO, temporary or temporarily.
temporary flight restriction Order prohibiting un-
authorized aircraft from airspace above major accident,
natural disaster or other event.
temporary revision Document printed on yellow paper
which temporarily amends an item in a maintenance
manual [now also issued electronically].
TEMS Turbine-engine monitoring system.
TEN Tactical environment network (USMC).
Tencap Tactical exploitation of national capabilities

(US).
TEND Trend forecast.
tendency Variation with respect to time, esp. change
in atmospheric pressure in 3 h period prior to an obser-
vation.
Tenley Secure voice system for Tri-Tac, for NSA (US).
Tensabarrier Seat-belt-type barrier to control people
movements at airport (BAA); quickly closed or opened.
tensile strength Tensile force per unit cross-section
required to cause rupture.
tensile stress That produced by two external forces
acting in direct opposition tending to increase distance
between their points of application.
tensiometer Measures actual tensile stress in flexible
cable, such as flight-control circuit; can be used for
flexible bracing wires.
tensioner Self-contained mechanism inserted into cable
carrying tensile load, eg in manual flight-control system,
which maintains desired (usually constant) tension
throughout; often in form of spring-loaded quadrants.
tension field Surface within which tensile force acts, with
direction parallel to forces. Hence * beam, eg wing spar,
within which * acts diagonally in vertical plane, tending
to pull upper and lower booms together.
tension regulator See tensioner.
tent Quasi-conical upper compartment of long-
endurance balloon housing near-spherical helium cell, the
main purpose being thermal insulation.
tenuity factor In level bombing, correction for variation
with height of atmospheric density.

TEO Transferred-electron oscillator.
TEOC 1 Tactical electro-optical camera.
2 Technical-objective camera.
TEORS Tactical electro-optical reconnaissance system.
TEOSS, Teoss 1 Tactical emitter operational support
system; EW locator (USAF).
2 Tracking electro-optical sensor suite.
TEP Tactical electronic plot.
tephigram Graphical plot of atmospheric temperature
and entropy on grid of intersecting isothermals and
isentropic lines against vertical axis of height (decreasing
pressure levels); also written T
φ
gram, for temperature
and entropy. Pronounced tee-fie-gram.
Tepigen Television picture generation (or generator).
Tepop Tracking-error propagation and orbit
prediction.
TER 1 Triple ejector rack.
2 Total-energy requirements.
3 Terrain-following radar (TFR preferred).
TERA Terminal effects research and analysis.
tera Prefix = × 10
12
, symbol T.
terabit One trillion bits/s.
teraflops One trillion flops = 10
12
operations per second.
TeraGrid Most powerful computing system, created in

US under auspices of NSF by linking 3,300+ processors
to give speed of 13.6+ teraflops and storage of 450+ tril-
lion bytes.
terbium Tb, soft silvery metal, density 8.23, MPt
1,356°C, importance growing.
Tercom Terrain comparison or terrain contour-
matching; navigation technique in which vehicle guidance
memory compares profiles of terrain below, sensed as
unique sequences of digital height measures, with those
already stored; hence, each match with terrain increases
accuracy of refinement of basic (eg INS) guidance,
whereas most systems degrade with time.
térébenthine Refined turpentine used as rocket fuel (F).
Terec Tactical electronic reconnaissance (Litton).
TERLS Thumba Equatorial Rocket Launching Station
(UN facility in India).
Term Terminates.
terminal 1 Building, either discrete or dispersed, at
airport which links airside with landside and through
which all passenger traffic passes, or through which all
cargo traffic passes. Very seldom is there one * for pax and
cargo, and at many major hub airports each airline or
group of airlines has its own *.
2 Downtown (city-centre) building at which passengers
may check in for flights and from which they may be
conveyed by public transport with baggage already
checked to pass straight through a * (1).
temperature correction terminal
631
3 Normal general meaning of being connecting point

through which flow passes into or out of a system in elec-
tric circuits, air traffic, data processing and many other
disciplines.
4 Final portion of flight of missile between midcourse
and target.
terminal airport That at which flight terminates. Also
correctly used as point at which particular item of traffic
leaves flight.
terminal alternate Alternate named in flightplan as
second-choice terminal (3) if for any reason normal desti-
nation unattainable.
terminal area See terminal control area.
terminal ballistics Behaviour of projectiles at impact
with, and penetration of, target.
terminal building See terminal (1).
terminal clearance capacity Maximum amount of cargo
or personnel that can be moved through terminal (3) daily
(DoD).
terminal communications Communications services or
facilities within terminal control area other than those
used for approach or ground movement.
terminal control area Airspace control area, or portion
thereof, normally at confluence of airways or air traffic
service routes in vicinity of one or more airports. Extends
from surface or from higher FL to specified FL and within
it all aircraft are subject to specified rules and require-
ments. Often a TMA.
terminal count Final portion of countdown ending in
lift-off.
terminal guidance 1 That governing trajectory from end

of midcourse to impact with or detonation beside target.
2 Electronic, mechanical, visual or other assistance
given to aircraft pilot to facilitate arrival at, operation
within or over, or departure from, air landing or airdrop
facility (DoD).
terminal manoeuvring area, TMA Controlled airspace
region surrounding busiest airports (usually large city
with many airfields); normally permanent IFR with other
traffic by dispensation.
terminal nosedive Vertical dive at full power (arch.).
terminal phase 1 Portion of trajectory of ballistic missile
between re-entry and target. Also other meanings in
particular space missions, eg LM/CM redocking in lunar
orbit.
2 Final part of missile trajectory after missile’s own
seeker has detected and locked on to target.
terminal radar service area Primarily an electronic
environment, not extending below a floor at medium FL,
providing radar vectoring and sequencing of all IFR and
VFR aircraft landing at primary airport, separation of all
aircraft in TRSA service area, and advisories on all
unidentified aircraft on a workload-permitting basis.
terminal velocity 1 Highest speed of which aeroplane
(rarely, other aircraft) is capable, reached at end of
infinitely long vertical dive at full power through uniform
atmosphere (suggest arch.).
2 Ultimate speed reached by inert body in free fall
through particular prescribed atmosphere.
terminal VOR VOR located at or near airport at which
particular flight terminates and specified as navaid used

in final approach clearance.
terminating bar lights Red lights between final-approach
lights and wing-bar lights.
terminator 1 Solid-propellant rocket subsystem
comprising signal input, squib or detonator and blow-out
port(s) for causing immediate thrust termination.
2 Boundary between sunlit and dark sides of planetary
body, eg Earth, Moon.
TERMM Transportable emergency-response moni-
toring module.
Terms Terminal management system.
Tern, TERN Terminal and en route nav.
ternary Device capable of three states, normally called
0,1, x.
terne plate US term for tinned, or lead-coated, mild steel
sheet (not plate).
Terp 1 Turbine-engine reliability programme.
2 Terminal instrument-approach procedure [see Terps].
Terpes Tactical electronic reconnaissance processing
and evaluation system (primarily USN/USMC).
Terprom Terrain profile matching, usually similar in
principle to Tercom.
Terps Terminal en-route procedures (FAA).
terrain-avoidance system System, usually radar-based,
providing pilot or other crew member with situation
display of ground or obstacles ahead which project above
either horizontal plane parallel to aircraft or plane
containing aircraft pitch/roll axes so that pilot can
manoeuvre aircraft laterally to avoid obstruction. Radar
becomes primary flight instrument.

terrain board Physical model of landscape formerly used
in simulation of air activity.
terrain-clearance system System, usually radar-based,
providing pilot or autopilot with climb/dive signals such
that aircraft maintains preset flight level while clearing
peaks within selected height in vertical plane through
flight vector. Unlike terrain-following, after each
protruding peak aircraft levels out at prescribed FL.
terrain comparison See Tercom.
terrain database Comprises computer-stored 2-D grid of
ground spot heights plus land culture information.
terrain-following system System, usually radar-based,
which provides pilot or autopilot with climb/dive signals
such that aircraft will maintain as closely as possible a
selected lo height above ground contour in vertical plane
through flight vector. In effect system projects radar ski-
toe locus which slides over terrain ahead to give minimum
safe clearance.
terrain masking Obscuration of aerial and other targets
by hills or buildings, esp. as seen at acute grazing angles
by overland downlook radar.
terrain orientation Holding topographical map so that
aircraft heading is at top of sheet or folded sheet.
terrain profile Outline of profile of ground surface,
usually with vertical scale × 5 (sometimes × 10) published
on approach chart or other documents to assist pilots.
terrain-profile recorder Airborne instrument, recording
sensitive radar or laser altimeter, giving hard-copy
readout for mapping and surveying.
terrain-referenced navigation Terrestrial reference

guidance.
terrestrial radiation Earth IR radiation; also called
eradiation.
terrestrial reference guidance Any method providing
steering intelligence from characteristics (usually stored as
quantified digital measures) of surface being overflown,
thereby achieving flight along a predetermined path
terminal airport terrestrial reference guidance
632
without the need for emissions. One example is Tercom.
Also called terrain-reference [or referenced] navigation.
terrestrial refraction Refraction observed in light from
source within Earth atmosphere; thus caused only by
inhomogeneities of atmosphere itself.
terrestrial scintillation Generalized term for scintillation
effects observed in light from sources within Earth atmos-
phere; also called atmospheric boil, optical haze and
shimmer.
Tersi Series of EW jamming and aerial-pattern
simulators.
tertiary airflow That passing through tertiary holes.
tertiary holes Apertures in gas-turbine flame tube or
combustor downstream of secondary holes admitting air
purely for dilution and cooling purposes to achieve
desired uniform gas temperature across chamber exit
plane.
TERTM Thermal-expansion resin transfer machine.
TES 1 Test and evaluation squadron.
2 Technology Experiment Satellite (India).
3 Tactical environment, or engagement, simulation [or

system].
4 Thermal emission spectrometer.
5 Transportable Earth station.
6 Threat-emitter system.
7 Trials end system (ATN).
TESAC, Tesac Training and evaluation system for
active countermeasures.
Tesar 1 Tactically enhanced synthetic-aperture radar.
2 Tactical-endurance synthetic-aperture radar (UAV)
or search and rescue.
tesla SI unit of magnetic flux density; 1T = 1 Wb/m
2
=
10
4
G.
tesla coil Induction coil without iron core normally
giving HF output.
TES-N Tactical exploitation system – Navy (USN).
Tess 1 Tactical engagement, or threat-emitter, simula-
tion system.
2 Transport efficiency support system.
Test Checklist at start of takeoff: time, engine instru-
ments, strobe, transponder.
testbed Mounting, either on ground or in form of
aircraft, upon which item can be mounted or installed for
test purposes. When an aircraft may be, but not neces-
sarily, prefixed by ‘flight’ or ‘flying’. In US normally
called test stand.
test cell Usually horizontal test stand, eg for rocket

motor, surrounded except on operative side by protective
shelter giving protection from weather and limited pro-
tection externally from explosion inside.
test chamber Environmentally controlled sealed
chamber in which test can take place; eg can simulate
stratosphere or hard vacuum with space solar radiation.
test clip Spring-steel clip for quick electrical connections
to terminals.
test club Club propeller making no pretence at aerofoil
shape but merely having stubby projecting arms in correct
balance.
test diamond Region in supersonic tunnel working
section within which model is placed and within which
flow conditions are essentially constant at any one time.
test firing Firing of rocket, of any type, while mounted
on testbed (test stand).
test flight Flight by aircraft, winged spacecraft or cruise
missile for purpose of evaluating or measuring per-
formance, handling or system operation.
test pattern Geometric pattern used in testing electronic
displays.
test program[me] set Small box which is brought to
check out cockpit processors.
test rig See rig (3).
test section 1 Tunnel working section.
2 Special glove aerofoil carried on flying testbed.
test set Packaged equipment, either versatile or for
testing specific system, of electronic, hydraulic, pneu-
matic, microwave/RF or any other character, which can
readily be brought to aircraft or have device brought to it.

test vehicle Air vehicle, normally unmanned, built to test
major element of its design, construction or systems and
thus prove new concept.
TET 1 Turbine-entry temperature, see turbine temp-
eratures.
2 Tolerable exposure time, esp. with reference to
aircraft in high-speed flight in gusts.
3 Technical evaluation test.
TETA Triethylene-triamine.
Tete Total estimated time en route.
tethered satellite One connected to a space station,
Shuttle Orbiter or other parent body by a fine cable up to
100 km (62.1 miles) in length.
Tetra 1 Turbine-engine transient response analyser
(EDP code).
2 Terrestrial trunked radio.
tetraethyl lead Liquid added to some petrols (gasolines)
to improve resistance to detonation (anti-knock value or
fuel grade); base material is Pb(C
2
H
5
)
4
. Resulting fuel is
called leaded.
tetrode Thermionic valve (tube) containing cathode,
plate and two other electrodes.
Tetwog Turbine-engine testing working group.
TEU Trailing edge up.

TEV Test, evaluation and verification.
Tevi Turbine-engine vibration indicator.
Tewa, TEWA Threat-evaluation and weapon
assignment.
TEWS, Tews Tactical electronic-warfare suite, or elec-
tronic warning system.
TEWT Pronounced tute, tactical exercise without
troops.
Textolite Obsolete ‘plastics’; hot pressed canvas/resin
laminates.
textured visuals Visuals whose CGI tones are not plain
grey shades but have texture corresponding to real life,
giving enhanced spatial cues. Usually achieved by digital
and photographic imagery combined.
TEZ Total exclusion zone.
TF 1 Trip fuel.
2 US military engine-designation prefix: turbofan.
3 US military aircraft designation prefix: fighter
trainer; dual version of established fighter.
4 Turbine fuel is available.
5 Toroidal field.
6 Technology forecasting.
7 Torpedo (armed) fighter (UK, pre-1953).
8 Terrain-following.
9 Thin film.
10 Tandem fan.
11 Task force.
terrestrial refraction TF
633
12 Toll free.

13 Time/frequency (or T/F).
T
f
1 Temperature at flexible T-O rating.
2 Fuel temperature.
t
f
Radar frame time.
TFA Transfer-function analyser.
t
fa
Average time between false alarms.
T-fast Technology for frequency-agile digital synthe-
sized transmitters.
TFB Tower fly-by.
TFC 1 Total final consumption.
2 Tactical fusion centre (AAFCE).
3 Tactical fire control.
4 Tactical flag command; C adds centre.
tfc Traffic (FAA).
TFD 1 Thin-film diode.
2 Time/frequency display.
TFE 1 Terrain-following E-scope.
2 Therminioc fuel element.
3 Tetrafluoroethylene, major additive to magnesium
IRCM.
TFEC Tactical fighter electronic combat.
TFEL Thin-film electroluminescent display, a CRT
alternative.
TFF Tri-fluid fuel.

TFG 1 Thrust-floated gyro.
2 Tactical Fighter Group.
TFH Thick-film hybrid.
TF/HF Tandem fan, hybrid fan.
T-fix Elapsed time since last update of position of
moving surface target.
TFK Trainer facility kit.
T-Flir Targeting FLIR.
TFM 1 Tactical flight management system.
2 Traffic flow management.
TFMS Tactical frequency-management system.
TFOV Total field of view, limited in HUD by head
freedom and optical aberrations.
TFP Technology forecast panel
TFPA Torso front protective armour.
TFPRT Thin-film platinum resistance thermometer.
TFR 1 Terrain-following radar.
2 Total fuel remaining.
3 Temporary flight restriction area (FAA).
TFS Tactical Fighter Squadron.
TFSB Tungsten-filament seven-bar display.
TFSF Time to first system failure.
TFSUSS Task-force on scientific users of space station.
TFT 1 Thin-film transistor.
2 Trim for takeoff.
TFTA
2
Terrain following, terrain avoidance, threat
avoidance.
TFTP Trivial file transfer protocol.

TFTS 1 Tactical Fighter Training Squadron.
2 Terrestrial flight telecommunications, or telephone,
system.
TFU 1 Turret Flir unit.
2 Technical follow-up.
TFW Tactical Fighter Wing.
TFWC Tactical Fighter Weapons Center.
TG 1 Transportgeschwader (G).
2 Tactical, or Task, Group.
3 Techniques generator (EW).
4 Transmission gate.
5 Training glider (USAAF, 1941–47).
6 Timer – VDL management entity.
7 Terminal guidance.
Tg Tropical Gulf.
TGA Target gate analysis.
TGAT Tactical GPS anti-jam technology.
TGB Transfer gearbox.
TGC 1 Travel-group charter (US term, basically = UK
ABC).
2 Turbulence gain control.
TGCR Tactical generic cable replacement (FO trans-
mission system).
TG4 Maximum time between GSIF’s timer.
TGG Third-generation gyro (Northrop).
TGIF Transportable ground interface facility.
TGL 1 Touch-and-go landing (ICAO).
2 Temporary guidance leaflet (FAA).
TGO Thermally-grown oxide.
TGP 1 Twin-gyro platform.

2 Terminally guided projectile.
TGS 1 Triglycine sulphate; pyroelectric IR detector
material.
2 Taxiing, or taxiway, guidance system, (ICAO) or
sign.
3 Turreted gun system.
4 Maximum link-overlap timer.
TGSM Terminally guided sub-muniton.
TGT Turbine gas temperature.
2 Target.
3 Titanium/graphite/titanium.
Tgt Opp Target of opportunity.
TG3 Ground-station’s maximum time between trans-
missions.
TGW Terminally guided weapon.
TH True heading.
T
H
Total temperature.
THAAD Theater high-altitude air defense [S adds
system] (USA).
THAD Terminal-homing accuracy demonstrator.
Thagg Tactical high-antijam GPS guidance.
THAR Tyre height above runway.
THAWS, Thaws Tactical homing and warning system
(RCA).
THDG True heading.
THDR Thunder.
theatre Geographical area of military operations in
which commander of unified or specified command has

complete responsibility; today used as adjective, often
synonymous with tactical.
theatre range Range of combat aircraft within a theatre,
as distinct from deploy range.
Thel, THEL 1 Tactical high-energy laser.
2 Theater high-energy laser (US, Israel).
Thelact Tactical high-energy laser advanced-concept
technology.
The LTAS The Lighter-Than-Air Society (Akron, OH,
US).
Themis Thermal-emission imaging system.
Then Year Actual funds voted or spent; must be
factored for inflation to enable comparison to be made
with ‘now’.
theodolite Optical sight or telescope whose az/el can be
accurately read off angular scales.
T
f
theodolite
634
theoretical gravity That at Earth’s surface if Earth’s
mass was reshaped as perfect sphere.
theoretical thrust coefficient A thrust/time value for
solid-propellant rockets computed from large equation
involving an effective value and assumed conditions for
various areas and pressures. Symbol C
°
1
.
therapeutic adaptor Coupled to continuous-flow oxygen

mask, approximately triples flow rate; used for passengers
with respiratory or heart problem.
therapeutic oxygen Administered primarily to treat
ailment, eg pulmonary or cardiac faults.
therm Non-SI unit of energy = 10
5
BTU = 105.506 MJ.
thermal 1 Local column of rising air in atmosphere,
usually caused by surface heat source.
2 To use (1) as energy input for soaring flight.
thermal acoustic fatigue Fatigue of structure caused by
impingement or close proximity of hot gas jet.
thermal anticing Anticing by heating affected surface.
thermal barrier Notional barrier to further increase in
some variable, eg flight speed in atmosphere or turbine
entry temperature in engines, caused by inability of
materials to withstand increased temperatures.
Continually being eroded by new refractory materials.
thermal barrier coating Vast range of refractory
materials, usually deposited by electron beam or plasma
spray, based on zirconia, yttrium and similar exotics.
thermal battery Electrical cell stored inactive and
activated chemically for one-shot high-power output.
thermal blooming See blooming.
thermal coefficient of expansion Increase of (1) length
per unit length, or (2) area per unit area, or (3) volume per
unit volume, caused by rise in temperature of 1°C (often
defined as from 0° to 1°C, or from 15° to 16°C).
thermal conductance Rate of flow of heat per unit time
through unit cross-section area; 1 BTU.ft

-2
h.°F = 5.67826
Wm
-2
h.°C; 1 Wm
-2
h.°C = 0.17611 BTU.ft
-2
.h.°F.
thermal conductivity Time rate of flow of heat through
unit area normal to temperature gradient per unit T°
difference. Symbol
λ
or k, rate given by Fourier’s law. SI
unit is Wm
-1
K
-1
; Imperial (obs.) might be BTU ft
–1
s
–1
F
–1
.
thermal cueing unit Adjunct to FLIR-based attack
system which puts marker boxes round all likely surface
targets, picking them according to their high temperature,
and which automatically feeds target co-ordinates to the
attack system if any of these boxes is touched by the pilot

on the HDD touch display.
thermal cycling Oscillating between low and high
temperatures.
thermal de-icing De-icing by heating affected surface.
thermal diffusivity Measure of transfer of heat by dif-
fusion analogous to viscous motion; symbol
α
=
λ
/
ρ
C
p
.
thermal diode Solid-state generator of electricity
comprising layer of semiconductor at room temperature
joined by thermal insulative layer to layer heated to
250–450°C.
thermal efficiency Basic efficiency parameter of heat
engine, defined as percentage ratio of work done in given
time to mechanical equivalent of heat energy burned in
fuel supplied in same period.
thermal emission EM radiation solely due to body’s
temperature (which if hot enough contains strong visible
radiation).
thermal excitation Acquisition of excess energy by
atoms or molecules as result of collisions.
thermal expansion Increase in dimensions caused by
increase in temperature.
thermal exposure Calories/cm

2
received by normal
surface in course of complete NW detonation (DoD).
thermal fatigue Mechanical fatigue caused by stresses
repeatedly imposed by thermal cycling.
thermal gradient See temperature gradient.
thermal gradiometer Airborne instrument for detecting
thermals by thermocouples on wing-tips which, in
presence of temperature difference, sends electrical signal
to cockpit indicator.
thermal heating Tautological; kinetic heating is meant.
thermal imagery Produced by measuring and electroni-
cally recording thermal radiation from objects (NATO).
Normally IR wavelengths only are implied. Hence
thermal imaging, to produce pictorial displays or print-
outs showing variation of temperature over field of view.
thermal index A forecast value of the temperature differ-
ence between sinking and rising air.
thermal instability Any combination of temperature
gradient, thermal conductivity and viscosity resulting in
convective currents, eg wind in atmosphere.
thermal keel Generated by positioning engine jet nozzles
well forward under the fuselage [helps reduce generation
of sonic boom].
thermal lift 1 Lift due to thermal (1).
2 Lift imparted to air mass because of greater density of
cold surrounding air, not quite synonymous with (1).
thermal load Imprecise term usually meaning temp-
erature gradient or temperature stress.
thermally expanded metal Fabrication of parts from

aluminium alloy sheets rolled together with intervening
patterns of ‘ink’; the latter prevents the sheets bonding
and, on subsequent heating, expands to force the
unbonded parts to fit a mould.
thermal neutron Neutron slowed, eg in moderator, to
thermal equilibrium with surroundings at about 2,200 m/s
(so-called slow neutron); * analysis is principal method
used in detecting presence of explosives.
thermal noise RF noise caused by thermal agitation in
dissipative body (any conductor or semiconductor), also
called Johnson noise.
thermal picture synthesizer Matrix of heat-emitting thin-
film resistors on Si substrate, each representing
individually addressed pixel to give overall large picture
rate of 50 Hz.
thermal protection Protection against kinetic heating
during atmospheric entry (re-entry) of spacecraft struc-
ture, RV or other body, esp. one intended for repeated
space missions.
thermal pulse Total IR emission from NW detonation,
or plot of IR flux against time during complete burst and
fireball climb.
thermal radiation 1 See thermal emission.
2 Total heat and light radiation produced by NW
detonation (DoD).
thermal relief valve Safety valve in fluid system to guard
against excessive pressure caused by overheating.
thermal runaway 1 Fault condition with element of
danger affecting Ni/Cd batteries characterized by par-
ticular cells losing resistance (possibly because of high

temperature) and thus taking increased current, lowering
resistance still further in chain-reactive process.
theoretical gravity thermal runaway
635
2 Similar divergent overheating in current-carrying
transistor.
thermal sensitivity Of IR camera, quantified difference
in temperature required to output different tonal value
between black/white, typically 0.02–0.1°C.
thermal shock Severe mechanical stress resulting from
sudden extreme temperature gradient.
thermal soaring See soaring.
thermal stress See temperature stress.
thermal switch Switch activated by temperature differ-
ence or particular temperature.
thermal thicket Flight conditions in which kinetic
heating (or other thermal problems) is a factor to be
considered but does not yet impose a thermal barrier
(colloq.).
thermal wind Notional vector difference between winds
at different heights, caused by horizontal variation of
atmospheric temperature and hence pressure at all upper
heights (note: not pressure surfaces).
thermal X-rays EM radiation, mainly in soft (low
energy) X-ray region, emitted by extremely hot NW
debris.
thermel Any device based on Seebeck, eg thermocouple,
thermopile.
thermie Non-SI unit of work (mechanical energy); 1 th
= 4.1855 MJ.

thermionic Involving electrons emitted from hot bodies.
thermionic converter Electric generator powered by hot
emitter and cold collector.
thermionic rectifier Depends on unidirectional electron
flow from cathode to anode.
thermionic tube See thermionic valve.
thermionic valve Evacuated capsule, usually glass,
containing heated cathode emitting electrons attracted to
anode, usually via one or more intervening control elec-
trodes usually called grids. In US called vacuum tube.
thermistor Protective resistor based on semiconductor
having high negative temperature coefficient of
resistance.
thermite Mixture of finely divided magnesium and iron
oxide used as heat source in welding and as incendiary
filling; originally spelt with capital T.
thermobaric warhead Creating both high-temperature
and blast-wave effects [often said of FAE].
thermobarograph Provides continuous readout of
temperature and pressure.
thermochemistry Branch of chemistry concerned with
thermally induced reactions and relationship between
chemical changes and heat.
thermochromic LO technology in which appearance is
changed by variation in temperature.
thermochromic tube CRT with phosphor replaced by
heat-sensitive layer.
thermocline Sharp submarine temperature gradient.
thermocouple Instrument based on Seebeck effect
which measures temperature difference between pair of

dissimilar-metal junctions; much used for high-
temperature measures using refractory metals, and in
common copper/constantan junction at room temp-
erature, eg for met. observation.
thermodynamics Science based upon heat flow and
temperature changes, esp. those in moving fluids.
thermodynamic cycle Operating cycle of any heat
engine. In some, eg virtually all piston engines, one parcel
of fluid at a time goes through complete ** in same
enclosed (usually variable-size) volume; in others, eg gas
turbines, continuous flow of fluid goes through ** by
passing from one part of device to another, each com-
ponent handling only one part of **. The working fluid
may be recycled, continually changing state liquid/
vapour.
thermodynamic efficiency See thermal efficiency.
thermodynamic energy equations Exact expressions of
variation of pressure, volume and temperature in
reversible processes in perfect gas.
thermodynamic equilibrium Time-invariant state in
which all processes are balanced by reverse process and
entropy production vanishes.
thermoelectric cooling Local cooling using Peltier and
cooling ‘hot’ junction; ‘cold’ junction then falls to desired
level at -20 to -30°C.
thermoelectric generator Electric generator based on
thermocouples using Seebeck, Thompson, Kelvin or
Peltier effects; common spacecraft systems use nuclear
reactor or radio-isotope to heat junction often based on
Ge/Si alloy.

thermogram 1 Single-line output of traditional thermo-
graph.
2 Pictorial output of thermographic camera.
thermograph Recording thermometer using pen/chart
or light-spot trace on film. Output is a thermogram.
thermographic camera IR camera, usually of IRLS type.
thermography Translation of temperature changes in a
scanned scene into visual picture, today important in mili-
tary and civil aerial reconnaissance, industrial process
control, medicine and many other fields. Either
black/white (black = cold, white = hot) or colour.
thermohydrometer Hydrometer with thermometer,
giving two chart outputs.
thermometer Instrument for measuring temperature.
thermometer screen Louvred box screening
thermometer from direct sunlight; usually contains other
met. instruments and in US called instrument shelter.
thermonuclear Processes in which extremely high
temperatures are used to initiate fusion of light nuclei.
thermonuclear weapon Hydrogen bomb.
thermopile
Thermoelectric generator comprising stack
of thermocouples.
thermoplastic recording Patented (GE) process for
recording sound or video signals via electron beam direct
on thermoplastic layer heated by microscopic currents
induced in underlying conductive layer.
thermoplastics Large class of synthetic polymers which
may be repeatedly softened and remoulded by heating.
thermosetting plastics Synthetic polymers that are chem-

ically changed irreversibly by chemical action, for
example a hardening agent, or by EM radiation, notably
heat or UV irradiation, generally setting hard.
thermosphere Outermost region of atmosphere from top
of mesosphere outwards into space, characterized by
more or less steadily increasing temperature with distance
from Earth.
thermostat Device for maintaining a desired temp-
erature by taking action at preset limits of low and high
temperature.
thermotropic model Atmosphere used in forecasting one
temperature and one pressure surface.
Thesh Threshold, also Thld, THR.
thermal sensitivity Thesh
636
theta Greek letter
θ
, used for many parameters,
including pitch angle (thus,
θ
= pitch rate) and azimuth
(hence R
θ
). See Appendix 1.
THI Tactical hit indicator.
thickened fuel Aircraft fuel designed to resist fine dis-
persion and instead to break down in crash into globules
with near-zero surrounding vapour; generally synony-
mous with gelled fuel.
thick-film Very diverse technology of electronics

involving processing, high-current devices, current-
generation (inc. solar cells) and many other topics, mainly
using insulating substrates but often with semiconductor
layer.
thickness Of wing, maximum straight-line distance from
external skin of upper surface to external skin of lower
surface measured in plane of aerofoil profile and perpen-
dicular to chord line.
thickness/chord Ratio of thickness to chord of wing,
both measured in plane of aerofoil profile at same station.
thickness distance Distance aft of leading edge of
maximum thickness of supersonic rhomboidal or double-
wedge wing, expressed as % chord.
thickness gauge See feeler gauge.
thickness lines Lines joining points on chart where
vertical distance between pressure surfaces is everywhere
same.
thickness ratio Wing t/c ratio.
thimble 1 Pear-shaped eye around which end of control
cable is spliced.
2 Ratchet turning knob of hand micrometer.
3 Pimple-like radome, especially on or under nose
[usually adjective].
thin-case bomb Conventional bomb for blast effect
against soft target. Also called light-case (UK, WW2).
thindown Progressive energy loss by primary cosmic
rays in ionising surrounding medium.
thin-film circuit Electrical or electronic circuit formed by
depositing thin film on (usually insulating) substrate;
normal manufacturing methods are vacuum deposition

and cathode sputtering. Films may be conductive, semi-
conductor or insulating.
thin-film lubrication Imperfect, with occasional
metal/metal contact.
thin-film transistor IGFET constructed by evaporating
on to insulating substrate metal electrodes, semi-
conductor layer(s), insulating upper layer and metallic
gate; abb. TFT.
think tank Centralized group of people normally
working for government or large corporation engaged in
futures, forecasting, ultra-new technologies and other
disciplines calling for visionary judgement.
thinner(s) Solvents for paint, dope and other liquids to
reduce viscosity.
thin route Airline route, usually intercontinental,
offering only modest traffic.
thin-tape system Applied to aircraft skin to increase
stealthiness of joints.
THIR Temperature, humidity and IR radiometer.
third-angle projection Convention in engineering
drawing in which front view, side elevation and plan each
show face nearest to it in adjacent view; traditional US
arrangement becoming standard in European aerospace.
third-level carrier Generalized term for ‘third tier’ of
scheduled airline operations, also called feeder or
commuter and often of radial nature serving single city
hub. No clear demarcation separating from second-level
(local-service or regional).
thixotropic Becoming liquid when vibrated or stirred,
setting after standing for a period.

THK 1 Turk Hava Kurumu (national air-sport associa-
tion, Turkey).
2 Thick.
THL 1 Tailplane hinge line.
2 Tourelle hélicoptere leger (F).
Thld Threshold.
THN Thin.
ThO
2
Thorium oxide.
Thor, THOR 1 Thermionic opening reactor (burst
power up to GW range).
2 Terahertz operational reachback (Darpa).
thorium Th, silvery radioactive metal, density 11.7, MPt
1,750°C.
Thornel Tradename for carbon and graphite fibres.
thou Thousandth of an inch, 25.4 µ.
THP 1 Thrust horsepower, often thp.
2 Through-hole plated.
3 Turbo-hydraulic pump.
4 Total-head pressure.
THR 1 Threshold, threshold lights.
2 Turboreacteur à hélice rapide = propfan (F).
3 Thrust.
thread chaser Tool for removing contamination, eg
paint or dirt, from thread.
thread filter Long fine screwthread on outer surface of
cartridge inserted tightly into surrounding unthreaded
cylinder to filter fine fragments, typically as last-chance *
before oil reaches vital feed jets.

thread gauge Hand gauge with many specimen threads,
one of which is matched with part.
threading the needle Process of accurately flying through
a small gate in airspace, eg in setting a speed record
(colloq.).
thread insert Steel helix screwed into soft (eg aluminium)
hole.
threat 1 Hostile anti-aircraft defences, especially air-
defence radars, SAM systems, AAA and fighters.
2 A target that has satisfied the * -detection logic and
therefore requires a traffic or resolution advisory (TCAS).
Threat awareness unit Minimum time flight crew need to
discern collision threat and take avoiding action; per-
formance envelope of aircraft divided by closure rate of
intruder.
threat circle Projected on cockpit display showing
computed region in which LO aircraft might expect to be
detected by particular hostile radars.
threat cloud Total collection of warheads, chaff and
other penetration aids in ICBM attack.
threat evaluation Process of detecting, analysing and
classifying hostile offensive systems, either in warning of
attack or during penetration of hostile territory when
systems are surface-to-air.
threat library Numerical characteristics of hostile
threats, especially EM emitters, stored in friendly
computer (eg of RWR receiver).
threat simulation Simulation of hostile offensive
systems, eg by add-ons to RPV target to include
emissions, dispensed payloads and jamming.

three-axis autopilot Has authority in pitch, roll and yaw.
theta three-axis autopilot
637
3-bar VASI Comprises VASI plus additional pair of
upwind (210 m, 700 ft) wing bars symmetrically disposed
about centreline each having at least two light units, for
use by LEW aircraft.
three-bearing nozzle Propulsive nozzle able to vector in
two planes for STOVL.
three-body problem Mechanics of motion of small body
in gravity of two others.
three-control aeroplane Conventional, with separate
pilot input for each rotational axis.
3-D cam Cam whose profile varies across its width and
which moves axially as well as rotationally.
3-D flow Fluid flow which cannot be represented fully in
2-D, eg flow over a real wing.
3-D radar Radar enabling position of target to be deter-
mined in 3-D space, either by Cartesian methods or, more
often, by az/el plus slant range.
3-D tool Jig or fixture used to define exact shape of
finished assembly, eg complex hydraulic piping or wiring
loom.
3E Environment, efficiency, economy.
three-float seaplane Main float on the centreline and
stabilizing float on left and right.
3GCS Third-generation cellular system[s].
three greens Landing gear is down and locked (colloq.).
3He Helium, valency 3.
3LM Third-level maintenance.

three-moment equation For solving bending moments
and other loads at ends of two adjoining spans of con-
tinuous beam.
3-P Planning, production, progress.
three-phase current Alternating electrical current made
up of three phases, each with vector separation of 120°;
carried by triple wire.
three-phase equilibrium See triple point.
3
φ
Three-phase current [3-phi].
three-pointer altimeter Dial instrument with short
needle for thousands (ft or m), mid-length for hundreds
and longest for tens.
three-point landing Correctly judged landing by
tailwheel-type aeroplane in which main and tail wheels
touch ground simultaneously with wing stalled.
three-point mooring Mooring for aerostat in which three
lines are run (often from single point, eg nose of airship)
to three ground anchors, usually at apices of equilateral
triangle.
three-point tanker Equipped with two outer-wing
HDUs and one at the tail.
3-pole switch Opens and closes three conductors or
circuits.
three-poster STOVL or V/STOL vectored-thrust
propulsion system having three jets; normally two cold
fan jets and one hot core jet, but alternatively two main
(rear) jets plus an auxiliary nose jet fed via a bleed air duct.
three-shaft engine Gas turbine having LP, IP and HP

shaft systems.
three-stream engine 1 Turbofan (HBPR) in which fan
thrust (probably VIGV modulated) and core jet are used
for propulsion and LP compressor (core supercharger) is
used for blowing purposes.
2 Any engine in which fan thrust, core thrust and lift
thrust or bleed are used separately.
3 to 1 rule Air distance 3 n.m. for each 1,000 ft lost in
letdown.
3-view drawing GA drawing, normally showing eleva-
tion (left side), front and plan.
3-way switch Routes input along either of two outputs.
3-wire Target of most carrier arrested landings, No 3
wire; hence ** landing.
3-wire circuit Neutral wire between two outer wires,
latter having potential difference from neutral equal to
half that between them.
threshold 1 Beginning of usable portion of runway, ie
downwind end.
2 In automatic control systems, point at which response
is first noticed, usually defined in terms of input displace-
ment (see * level).
3 Flight condition when fixed-wing aerodyne is on
point of stall.
4 Point at which sound just becomes audible (* of audi-
bility or of hearing), normally 2 × 10
-5
N/m
2
.

5 EAS giving lowest comfortable cruising, possibly
higher than that for minimum fuel.
6 See thresholds.
threshold contrast Smallest contrast in luminance visible
under given conditions.
threshold crossing height Height of glideslope above
threshold.
threshold curve Plot of sound frequency against noise
level in dB (or other noise measure) just audible against
quiet background, eg anechoic chamber.
threshold displacement Linear distance between end of
full-strength runway pavement and displaced threshold,
with latter shown on airfield charts as white bar across
runway crossed by narrow black line, and expressed as
minus quantity in certain navaid figures, eg Vorloc II
= Ҁ380 ft.
threshold dose Minimum quantity of radiation
producing detectable biological effect.
threshold illuminance Minimum value of illuminance
eye can detect under given dark adaptation and target
size; also called flux-density threshold.
threshold level Threshold (2), esp. in rate gyro devel-
oping electrical output as function of rate of turn; that
angular rate after rotational acceleration from rest at
which there is first indication of output, or change in
output; normal unit is °/s × 10
-6
.
threshold lights If fitted, bidirectional units, showing
green towards approach and red towards runway, in

continuous row across threshold (rare at displaced
threshold).
threshold limit value Average airborne concentration of
toxic substance[s] normal person can withstand 8 h per
day 5 days per week, usually expressed as ppm or mg/m
3
at 25°C/760 mm Hg.
threshold marking For simple runway, runway number
in white, visible to pilot on approach; if displaced
threshold, preceded by white transverse bar touched by
four arrowheads pointing upwind and preceded by series
of centreline arrows. For instrument runway, four bold
white axial stripes in rectangular group on each side
preceeding runway number.
thresholds Limits on programme monetary changes
imposed by US Defense Secretary.
threshold sampling time Time since overhaul at which
engines are removed and inspected in preparation for
extension in TBO; * may be less or more than new TBO.
threshold speed V
T
, VAT and VT max.
3-bar VASI threshold speed
638
THR HOLD Thrust, or throttle, hold.
THRFTR Thereafter.
throat Point of smallest cross-section in duct, especially
that in con/di nozzle, supersonic tunnel upstream of
working section, and rocket engine or motor thrust
chamber and nozzle.

throatable Jet or fluid flow controllable by changing
shape or area of throat (unusual except in tunnels).
throat control In gas turbines, system controlling flow
through nozzle guide vanes upstream of turbine.
throatless chamber Rocket thrust chamber without
throat yet still achieving supersonic expansion, eg multi-
chamber toroidal type.
throatless shear(s) Power shear for cutting large sheet or
plate which may be rotated during cut to leave curved
edge.
throat microphone Microphone held against skin of
throat; better for deep or guttural voices or languages.
throttle 1 Input control, usually hand lever rotating
through arc, for main vehicle propulsion.
2 System responsible under pilot for varying engine
power.
3 Valve in carburettor or fuel control which governs
admission to engine of either air, fuel or (piston engine
only) mixture.
4 To reduce power of engine, also called to * back.
5 To constrict fluid flow path and thus reduce mass
flow.
throttle back To reduce power.
throttle friction Pilot-operated device which greatly
increases resistance of throttle lever(s) to movement,
effectively locking them in set position; also called friction
lock.
throttle icing Ice accretion in carburettor near or on
partially closed throttle (3).
throttle lock See throttle friction.

throttle push Pilot action to increase power.
throttle sensitivity Change in thrust or power per unit
movement of throttle lever.
throttle tension Locking resistance value of friction lock.
throttling capability Range of thrust expressed as
percentage to 100, over which liquid rocket (occasionally
other type of engine or propulsion) is designed to operate.
through-deck ship Generally, one with flight deck un-
obstructed by any full-width superstructure, even though
not necessarily extending to bow.
through-stick feedback Characteristic of some auto-
pilots that, when engaged, pilots flight controls move.
through-thickness pinning Repair of major damage to
composite structure in which numerous fine pins are
collapsed by a foam carrier.
throw 1 Part of crankshaft to which conrod attached,
comprising webs and crankpin.
2 Loose measurement of distance to which ECS fresh-
air inlet projects, in absence of bulk cabin air movement.
thrower ring Flange on rotating shaft which flings off
leakage oil or other fluid.
throw weight Total mass of payload carried by ballistic
missile, in case of ICBM including warheads, RVs, decoys
and other penaids, post-boost propulsion and terminal
guidance systems.
THRP Port throttle (caption).
THRS Starboard throttle (caption).
THRU 1 Through.
2 I am switching you to
thrust Force, esp. that imparting propulsion, SI unit is

newton (N), conveniently multiplied in kN = 224.80 lb st;
1 lb st = 4.44483 N. Useful * of turbofan or turbojet is
resultant of all * generated by fan (positive), front of
combustor (positive), turbines (negative) and nozzles
(negative), * at each location being AP + where A
is area of flow cross section, P is pressure, W is mass flow
and V flow velocity. Overall net * is A (P-Po) +
where P is static pressure at nozzle, Po local atmospheric
pressure, V
j
is jet velocity and V velocity of aircraft.
thrust angle Acute angle between axis of nozzle of
canted solid motor and centreline axis of vehicle,
measured in plane passing through both axes if possible.
thrust augmentation Usually means afterburning, but
also applied to water injection, and to piston engine
ejector-exhaust schemes.
thrust-augmented wing Aeroplane wing in which
enhancement of circulation by powered-lift system also
gives significant additional thrust (many arrangements,
but augmentation of thrust invariably secondary
objective).
thrust axis Axis along which resultant propulsive thrust
acts. With a turbofan this is resultant of fan and core jets,
and with a turboprop that of propeller and (probably
angled) jet. In multiengined aircraft * can oscillate
because of engines outboard on flexible wing.
thrust bearing Bearing, usually tapered roller, needle or
ball, that resists axial shaft load due to propeller thrust.
thrust buildup Sequence of programmed events in large

rocket engine between ignition and liftoff.
thrust bump Sudden uncommanded change [especially
increase] in thrust.
thrust chamber Complete thrust-producing portion of
liquid rocket engine comprising combustion chamber and
nozzle, often mounted on gimbals; not applicable to other
types of engine.
thrust coefficient 1 For propeller, basic performance
calculation method based on Drzwiecki method of plot-
ting grading curve of thrust against blade radius, yielding
value k
T
, constant for each value of advance ratio J; **
then equals k
T
J
2
and has symbol C
T
. This is also measured
thrust divided by
ρ
n
2
D
4
where
ρ
is density, n rpm and D
diameter.

2 For rocket motor, measured ** is thrust: time integral
over action-time interval divided by product of average
throat area and integral of chamber pressure: time over
action-time interval, symbol C
f
.
3 For CC/BLC blowing slit, T/qS.
thrust component In propeller theory (Drzwiecki), force
on one element parallel to axis of rotation, T
c
; convenient
to plot T
c
as ordinate against blade radius, area under
curve being measure of total thrust, T = N½
ρ
V
2
∫
r
o
T
c
dr
where N is number of blades, ½
ρ
V
2
dynamic head and T
c

integrated between axis of rotation (or, in practice,
spinner diameter) and tip radius r.
thrust control computer AFCS computer providing
control of engine N
1
and thrust, computation of engine
limit parameters, and autothrottle.
thrust cutoff See cutoff.
thrust decay Gradual falloff in thrust of solid motor,
W(V
j
ҀV)
–––––––––
g
WV
–––––
g
THR HOLD thrust decay
639
usually a slow fall from peak to cutoff or burnout
followed by rapid ** over 2 to 8 s and to zero after perhaps
10–12 s.
thrust-decay system Idle-area reset (turbofan).
thrust deflector Various schemes for V/STOL or
STOVL, see four-poster, switch-in deflector, vectored
thrust, etc.
thrust equivalent horsepower See thrust horsepower.
thruster Small propulsor, normally any of many kinds
of rocket, used for spacecraft attitude control or fine
adjustment of velocity.

thrust face Side of propeller blade corresponding to
underside of aerofoil.
thrust/frontal area Jet-engine thrust divided by engine’s
nominal or published frontal area; fair criterion in early
days of jet propulsion but today meaningless. Important
only in highly supersonic aircraft, in which area of
propelling nozzle exceeds that of engine.
thrust horsepower Seldom-used measure attempting to
determine power imparted to aircraft. For propeller
aircraft normally engine bhp or shp multiplied by
propeller efficiency (in case of turboprop plus a variable
component due to exhaust thrust). For jet engines, basi-
cally thrust actually imparted to aircraft multiplied by
TAS, keeping units compatible. See equivalent horse-
power.
thrust lever Jet-engine throttle, or power lever.
thrust line Thrust axis.
thrust loading W/F, total mass (in this case, weight) of
jet-propelled vehicle divided by aggregate thrust, usually
calculated for SLS-TO condition; units lb/kN =
224.8 lb/lb st, reciprocal 0.004448; 1 lb/lb st = 102.04 kg
kN
-1
, reciprocal 0.0098.
thrust meter Instrument for measuring thrust, more
commonly of jet engine.
thrust power Appears always to be synonymous with
thrust horsepower.
thrust rating computer Central element in auto power
management system (ATS).

thrust rating panel AFCS cockpit display of limiting and
target values of engine parameters, and selectors for oper-
ating mode (climb, cruise, MCT or TO/GA) or FTO
temperature(s).
thrust reverser See reverser.
thrust section Portion of vehicle, esp. slender rocket,
containing propulsion.
thrust specific fuel consumption See specific fuel
consumption.
thrust spoiler Pilot-controlled spoiler which when actu-
ated diverts jet from jet engine (esp. from turbofan core)
to reduce thrust close to zero. Lighter and simpler than a
reverser and merely eliminates possibly embarrassing
idling thrust.
thrust structure In large ballistic vehicle propelled by
multiple rocket chambers, structure which transmits
thrust from all chambers and diffuses it into airframe.
Normally large tubular truss structure at rear but can
include side structures for laterally attached motors, eg
SRBs.
thrust terminator Any quick-acting device for termi-
nating thrust of solid rocket motor, including blow-off
ports, nozzle ejection and inert-liquid injection into case.
thrust time lag Time from abrupt throttle movement to
reach stabilized thrust or power.
thrust-vectoring Control of vehicle trajectory by
rotating thrust line, esp. that of rocket; may involve
gimballed chamber, rotation of chamber about skewed
axis, inert-liquid injection at nozzle-skirt periphery, jet
tabs, spoilers, refractory vanes and other methods; abb.

TVC.
thrust-weight ratio Basic measure of combat aeroplane
performance: thrust (normally SLS-TO) divided by total
mass of aircraft.
thrust wire Diagonal bracing wire transmitting airship
propulsion thrust to envelope.
THRUT Throughout.
THSA Trimmable horizontal-stabilizer actuator.
THSD Thousand[s].
THT Transient heat transfer.
THUM, Thum Meteorological readings of temperature
and humidity, hence * flight.
thumbprint Common meaning is aircraft T/W (thrust:
weight ratio) plotted against W/S (wing loading).
thumbstick Pilot input controller, eg for RPV or anti-
tank missile, in form of miniature stick operated by
thumb, typically attached to pistol grip and with * pivots
between vertical thumb and operator.
Thump Meteorological readings of temperature,
humidity and pressure.
thunderstorm effect Error, possibly approaching 180°,
of ADF in vicinity of thunderstorm; needle may point to
nearby Cb or flick over, giving false indication of station
passage.
thyratron Gas-discharge triode used as relay, switch or
sawtooth generator.
thyristor Multilayer semiconductor device also called
Si-controlled rectifier; bistable, in one state high-
impedance in both directions, in other high-impedance in
one direction only.

THz Terahertz.
TI 1 Target indicator.
2 Thermal imager, or infra-red.
3 Training [or tactics] instructor.
4 Trial installation.
5 Thermal index.
Ti Titanium; hence such alloys as Ti3Al2.5V, Ti6Al4V,
Ti6Al2Sn4Zr2Mo and Ti10V2Fe3Al.
TIA 1 Type inspection and authorization; allows FAA
to fly new aircraft.
2 Telephone interface adaptor card (TRV).
3 Telecommunications Industry Association (US).
TIAA Travel Industry Association of America.
TIACA The International Air Cargo Association
TIAD Tactical internet for air defence.
TiAl General symbol for titanium aluminides.
TIALD Thermal imaging airborne laser designator.
ti-aluminides Alloys of titanium and aluminium.
TIAS 1 Target identification and acquisition system
(ARMs).
2 True indicated airspeed.
TIB Technical Intelligence Bureau (former UK govern-
ment department, still a title in many countries).
TIBA Traffic information broadcast by aircraft.
Tibs, TIBS 1 Tactical information broadcast service
(USAF).
2 Telephone information briefing service.
TiB
2
Titanium boride.

TIC 1 Technical information centre.
thrust-decay system TIC
640
2 Tantalum integrated circuit.
3 Target-insertion controller.
4 Total inventory count.
5 Transport & Infrastructure Committee (US House of
Reps.).
6 Technologies of information and communication
(also F).
tic Visual marking pulse on telemetry readout indi-
cating time intervals, often every 0.5 s (see time *).
TICC Technical Information and Communications
Committee (ATA).
TICCS, TIC
2
S Target information command and
control system.
tick Audible marking pulse serving as regular (often
infrequent, eg each 10 s or 60 s) time signal.
ticket Pilot’s licence (colloquial, especially pre-1914).
TICM Thermal-imaging common module(s).
TiCo Titanium-colombium.
Ticonal Magnetic alloy of Ni/Co plus a little Al/Cu.
tic-tac airplane Miniature free-flight aircraft for sonic-
boom research.
TID 1 Tactical (or target) information display.
2 Touch input device.
3 Technical-interface description.
tiddleywinks effect Tendency of nose gear to project

stones and other loose objects laterally.
TIDLS, Tidals Tactical information data-link system.
TIDP Telemetry and image data processing.
tie Structural member normally loaded in tension.
tie bar Filament-wound tension member connecting
helicopter main-rotor blade to hub; fatigue-proof because
of large number of load-bearing members. Also called
dog-bone.
TIEC Tactical information exchange capability (RAF).
tied gyro Gyro whose rigidity is related to Earth rather
than space; eg that in traditional horizon has axis tied by
gravity aligned with local vertical.
tied on Air-intercept code: “Aircraft indicated is in
formation with me.”
tiedown 1 Picketing arrangement for aircraft left in open
(US).
2 Cargo lashing.
tiedown diagram Drawing illustrating method of
securing particular type or item of cargo in particular
vehicle (DoD).
tiedown point Permanent attachment point for cargo
provided on or in vehicle (DoD); hence * pattern.
tiedown test Rocket engine static test.
tie rod General term for tie of rod-like form, esp. with
threaded ends.
tiers Different levels assigned to subcontractors in
major programme; Tier 1 are usually assigned responsi-
bility for design and test, as well as manufacture.
Ties Tactical information exchange system.
TIF, Tif 1 Takeoff inhibit function, temporarily

suppresses all non-essential cockpit warnings.
2 Text interchange format.
3 Terminal interface function.
4 Tactical Imagery Intelligence Flight [not TIIF]
(RAF).
TIFS Total in-flight simulator.
TIG 1 Tungsten inert-gas welding.
2 Time of ignition.
Tiger 1 Targeting by image georegistration.
2 Terrifically insensitive to ground effect radar.
tightening Tendency of aeroplane or glider trimmed for
level flight to increase rate of a commanded turn or dive
pull-out, demanding a push force on stick or yoke to hold
constant g.
TIGO Prefix, US piston engine, turbocharged, direct-
injection, geared, opposed cylinders.
TiGr Titanium/graphite composite.
TII Threshold inspection interval.
TiiMs Texas Institute for Intelligent Bio-Nano
Materials and Structures for Aerospace Vehicles.
til Until.
tile 1 Thin-film or thick-film substrate; also occasion-
ally used for substrate of solar cell.
2 Discrete unit of surface thermal-protection system for
RV or large spacecraft, eg Space Shuttle, inspectable and
replaceable.
Till Tracking [and] illuminating laser (ABL).
TILS Tactical ILS.
tilt
1 Angular deviation of locus of centroids of sections

of helicopter main-rotor blade from plane of rotation
(BSI). Measured as forward or backward though actually
up/down.
2 Angular movement or offset of camera axis about
aircraft longitudinal axis (NATO).
tilt angle Angle between axis of air camera and aircraft
vertical (OZ) axis; normally angle at perspective centre
between photograph perpendicular and plumb line
(NATO).
tilt-body vehicle Usually synonymous with tilting
fuselage, standing upright on its tail for VTOL. A totally
different species has the wing and power (lift/propulsion)
system able to rotate up to 90° with respect to the free-
pivoted wing and tail; this family are usually STOLs.
tilting-duct VTOL VTOL aeroplane which in hovering
mode is lifted by ducted propellers or fans rotated through
approx. 90° for translational flight.
tilting-engine/jet/propeller/wing Same definition as
above but for different pivoted component. Tilting-jet
means entire engine is pivoted.
tilting fuselage Unusual class of VTOL aeroplanes in
which fuselage can be pivoted near mid-length, in some
cases complete with attached wing, in order for jet thrust
to act vertically. Also called nutcracker aircraft.
tilting head 1 Rotorcraft head pivoted about lateral axis
relative to supporting structure.
2 Machine-tool cutter and drive pivoted about hori-
zontal axis.
tilting-nozzle VTOL Not used; term is jet-deflection,
vectored-thrust, lift/cruise, vectoring or vectored-jet.

tilt-rotor VTOL aeroplane lifted in hovering mode by
one or (usually) more rotors which are rotated through
approx. 90° for translational flight.
tilt-wing VTOL aeroplane whose wing, carrying
complete propulsion system, is pivoted upwards through
approx. 90° in vertical mode, thrust then exceeding total
weight.
TIM 1 Total inventory management.
2 Training integrated [or integration] management [S
adds systems].
3 Target information module.
time Normally measured by subatomic frequency refer-
ence, eg crystal clock, but defined according to position of
celestial reference point; depending on which point chosen
tic time
641
* called solar (Sun), lunar (Moon) or sidereal (vernal
equinox), solar being subdivided into mean or apparent
according to which Sun. Practical time designated GMT
or according to designated longitude zone. SI unit is s,
3,600 to h, 86,400 to week.
timebase 1 Straight line traced by spot on CRT or other
display of cartesian and several other types providing
timescale for measurement, eg of target range.
2 Straight line, regularly incorporating time tic, on data
readout.
time between overhauls, TBO Period recommended by
manufacturer and beyond which all warranties become
invalid and operation may be in violation of certification.
time box Small box, usually rectangular or square,

which moves along cockpit display future track,
according to flight plan, at selected groundspeed.
time-change item One whose operation is limited to
number of operating hours, number of operating cycles or
(rarely) passage of time, and which must be periodically
replaced on this basis.
time circle Basic symbology of many HUDs and other
attack systems in which bright circle starts at 60 s and
unwinds anticlockwise to 180° at 30 s and to vanish at 0 s.
time-compliant technical order Mandatory instruction
for modification or for retrofit of equipment.
time constant 1 Usually, time taken from start of input
signal for instrument to indicate specified % final reading;
for exponential response, eg thermometer, time to reach
63.2% final reading; also called relaxation time, lag coef-
ficient. Same meaning in charge/discharge of electrical
C/R circuit or current in L/R circuit.
2 Time taken for aeroplane to reach maximum angular
velocity [any axis] after hard-over control input.
TIMED, Timed Thermosphere, ionosphere, meso-
sphere, energetics and dynamics satellite launched 2001
(NASA).
time dilation Apparent slowing-down of time as
observer’s speed reaches significant fraction of that of
light; also called clock paradox or twin paradox.
time dilution of precision Measure of errors [usually in
navigation] resulting from errors or variation in measured
or calculated time.
time/distance/speed scale Simple written scale, either
purchased (in which case of sliderule type) or prepared

before flight, with which unknown distance or speed can
be immediately read if other two factors are known.
time-division multiplex Dividing several continuous
measures, eg in telemetry system, or several input signals,
to form single continuous interlaced pulse train sent over
single channel to multiple receivers.
time-division multiplex access When multiple transmit-
ters are using a single carrier the carrier is time-shared to
avoid messages being garbled at receiver.
time group Four digits denoting time in hours and
minutes, such as 1730.
time hack Time at which a future event is scheduled, eg
at which a particular squadron is to start engines (colloq.
chiefly military).
time in service For maintenance time records, aircraft
log and similar purposes, elapsed time from aircraft
leaving surface until touching it again on landing (FAA).
time lag Any delay between stimulus and response, or
cause and effect, esp. that between start of signal and full
indication by instrument.
time mean bleed Short period of time during which large
RCS bleeds are expected to be used, and beyond which
thrust must be reduced.
time of flight Elapsed time from weapon launch, release
or departure from gun muzzle to instant it strikes target
or detonates.
time-of-flight spectrometer Instrument sorting particles,
esp. neutrons, according to time to travel known distance.
time of origin Local time message is released for
transmission.

time of useful consciousness See time reserve.
time on target 1 Time, either planned or actual, at which
aircraft attacks or photographs target.
2 Time at which NW detonation is planned at specified
GZ (DoD).
time over target Time at which aircraft arrive(s) over
designated point for purpose of conducting an air mission
on a target (USAF).
time pulse distributor EDP (1) circuit that generates
timing pulses during machine cycle, gated by command
generator to carry out commanded operations.
time reserve Time between sudden total loss of oxygen
supply and time when human can no longer be relied upon
to function normally or rationally.
time-response parameter Addition of input time delay to
assessment of response to pilot input of pitch rate
[rotation] and normal acceleration.
Time-Rite Patented indicator of piston position for
timing (1).
time series Sequence of time-variant measures, either
continuous (eg barograph trace) or discrete (eg hourly
met. pressure readings).
time sharing 1 Use of one EDP (1) processor or
computer, usually large and beyond means or require-
ments of each customer, by a number of customers or
users whose programs are run in short bursts in time-
division multiplexed form switched according to cyclic
formula agreed between users (in simplest form, a round
robin).
2 Planned allocation of time to external scanning [typi-

cally 18 s] and to looking around cockpit [typically 3 s].
time signal 1 Broadcast signal used as very accurate time
reference.
2 Time reference mark along border of reconnaissance
imagery or other film.
time/size plot Diagram whose ordinate is a measure of
aircraft size, eg MTOW or pax seats, and abscissa is time
in years.
time slot Slot (3).
time/speed scale Scale for given groundspeed used in
conjunction with plotting chart or topographical map.
timeswitch Electrical switch activated by time of day or
elapsed time from a start point.
time/temperature cycle recorder Records time engine
spends at critically high TGT, to give realistic indication
of hot-end life.
time tic Time reference mark along telemetry readout;
usually small inverted V every second along straight time-
base.
time tick Regular time signal of one or more audible
brief sounds.
time to go In air intercept, time to fly to offset point from
any other initial position; after offset point, time to fly to
intercept point (DoD).
timebase time to go
642
time zone Regions of local standard time, esp. over sea
areas, where they are exactly divided by 15° widths of
longitude.
timing 1 Angular positions of piston-engine crankshaft

at which valves first rise from seats or touch them again,
and at which spark occurs; also called valve *, ignition *.
2 In US, assessment of human pilot’s ability to co-
ordinate flight controls on correct time basis for smooth
manoeuvres; not often regarded as a topic elsewhere
unless demonstrably faulty.
timing consideration Measure of time missile (or,
possibly, other weapon such as aeroplane) is exposed on
ground between withdrawal from hardened shelter and
launch (probably arch.).
timing disc Disc, engraved marking or other feature on
piston engine to assist establishing exact crankshaft
angular positions for timing purposes.
timing parallax Film distance between time signal (2)
and corresponding frame of imagery.
timing pulse Pulse used as time reference in telemetry,
radar and SSR and other electronic systems.
TiMMC Titanium metal-matrix composite.
Timos Total-implant MOS device or circuit.
Tims, TIMS 1 Technology integration of missile
subsystems.
2 Tactical information management system.
3 Training Integration Management System, flight
scheduling and student records (USAF).
tin 1 Soft white metal, density 7.31, MPt 231.85°C,
symbol Sn (stannum).
2 To coat surface of mild steel sheet with tin to prevent
corrosion.
3 To coat metal surface with solder before making joint.
4 Aircraft, not necessarily metal (US colloq.).

Tina Thermal-imaging navigation aid.
tinfish Torpedo (UK colloq.).
TINS, Tins Thermal-imaging navigation system, or set.
Tinsel Transmitter carried by bomber to jam ground
instructions to German fighters (RAF WW2).
tin-strip Metal prefabricated-plank airstrip for STOVL.
t
int
Integration time, especially radar filter integration
time.
tin-tray game Stewardess trolley race.
tin wing Lightplane whose wings are metal-skinned.
TIO US piston engine designation: turbocharged, direct
injection, opposed.
TIOS Two-in-one service (Satcoms).
TIP 1 Message code: until past specified waypoint or
other point (ICAO).
2 Tracking and impact prediction.
3 Technical information panel (Agard).
4 Test integration plan.
5 Tailored instruction program (US).
6 Threat image projection, to test X-ray baggage
screeners.
7 Technical improvement program, or technically
improved product (IFF).
8 Transit improvement program.
9 Tiros information processor.
tip 1 Extremity of aerofoil.
2 Angle of rotation of reconnaissance camera about
aircraft transverse axis; also called pitch.

3 Wing-tip fuel tank (DoD) (colloq., adjective).
tip aileron Aileron forming most or all of tip of wing.
tip cargo Special cargo, eg radioactive isotopes, carried
in small compartment in wingtip of some transports.
tip chord Chord at tip of aerofoil, esp. wing, normally
measured parallel to plane or symmetry of wing (for
variable-sweep, at minimum sweep angle) between points
where straight leading/trailing edges meet curvature at tip.
Where both edges have pronounced sweep at tip, or where
they are joined by line not parallel to plane of symmetry
(eg Lightning, Tornado) other definitions apply, often
unique to type.
tip cropping Cutting off at Mach angle.
tip dragger 1 Spoiler above wingtip used asymmetrically
to cause yaw.
2 Sailplane (colloq.).
tip drive Rotation of main rotor(s) of rotocraft by thrust
applied at or near tips.
tip droop Downward folding of wingtips through large
angle, usually 60°–80°, to move forward aerodynamic
centre of wing at supersonic speed and decrease trim drag;
in some aircraft (XB-70) also generated compression lift.
tip float See stabilizing float.
tip generator Wingtip vortex generator.
TIPI Tactical information processing and interpreta-
tion system (USAF).
tip in To bank steeply away from takeoff flight path.
tip jet Any system providing propulsive thrust at the tip
of a helicopter main-rotor blade: pressure jet, cold
[compressed-air] jet, ramjet, pulsejet, rocket or turbojet.

tip loss Inefficiency of tip of aerofoil in lifting mode
caused by spanwise deflection of isobars and relative
wind, in some transonic cases approaching 90° and
making tip mere dead weight.
tip loss factor Correcting factor in calculating lift of
rotorcraft lifting rotor to allow for tip loss.
tip-path plane Plane containing path of tips of helicopter
or other rotorcraft main lifting rotor, tilted in direction of
travel or horizontal acceleration.
tipping See propeller tipping.
tip pod Streamlined container carried centred on or
below tip of aerofoil.
tip radius Usually synonymous with radius.
tip rake See rake.
Tips, TIPS 1 Total integrated pneumatic system (C-5).
2 Telemetry integrated processing system (AFSC).
3 Technical issue panels (FAA).
4 Transatlantic industrial proposal solution[s] (AGS6).
tipsail See winglet.
tip shroud Shroud 1.
tip speed Tangential speed of rotating tip of propeller or
rotor due solely to its rotation and ignoring superimposed
vehicle airspeed; i.e., V = r
ϖ
, radius multiplied by angular
velocity.
tip stall Stall of tip of aerofoil, esp. wing, while
remainder of surface remains unstalled; common con-
dition caused mainly by higher lift coefficient at tip unless
stall strip applied inboard.

tip tank Fuel tank formed as streamlined body, jettison-
able or otherwise, carried centred on or below wingtip.
tip trailing vortex See vortex.
tip vortex See vortex.
TIR 1 Total indicator reading.
2 Target-illuminating radar.
3 Tracking and illuminating radar
4 Thermal-imaging radar.
time zone TIR
643
5 Traffic information radar.
6 Thermal infra-red.
7 Twin intermeshing rotors (helicopter).
TIRC Tactical IR countermeasure.
tire UK spelling ‘tyre’ is used in this dictionary.
tiredness General deterioration of airframe caused by
long and intensive use, primarily manifest in repeated
cyclic loading and successive severe gusts but also
including superficial damage caused by impact of steps,
ground vehicles, stones etc; no significant crack need be
present but many structural parts will not be original and
many boltholes will be oversized and re-reamed for bolts
of increased diameter.
Tiros TV/IR observation satellite[s].
Tirp Terminal instrument radar procedure.
TIRS Transverse-impulse rocket subsystem (planetary
lander).
TIRSS Theatre intelligence, reconnaissance and
surveillance study (USAF).
TIS, tis 1 Tracking information (or instrumentation)

subsystem.
2 Thermal-imaging sensor, or system.
3 Tactical Intelligence Squadron.
4 Traffic information service(s) [aircraft-position
datalink, ground or airborne receiver].
5 Tactical input segment (satellite).
Tisar Terrestrial inverse SAR.
Tis-B Traffic information service, broadcast (FAA).
TISD Tactical Information Systems Division (Langley
AFB).
Tiseo Target-identification system, or sensor, electro-
optical.
TISH, Tish Thermal-imaging sensor head.
TISS, Tiss Thermal-imaging security system, or surveil-
lance system.
TIT Turbine inlet temperature; see turbine temp-
eratures.
tit Any control button, especially to fire guns (UK,
colloq., WW2).
Titan Thunderstorm identification, analysis and
‘nowcasting’, under development from 1990s (USWB,
NASA, FAA).
titanium Ti, hard silvery metal, density 4.5, MPt
1,660°C, reactive but bulk metal passivated by
oxide/nitride coating in atmosphere, vast range of aero-
space uses, main tonnage Ti-Al-V alloys, seeTi.
titanium aluminides Rapidly growing range of refrac-
tory (820°C) metals with properties marred only by poor
toughness and ductility.
Tite Tews intermediate test equipment.

title block Standardized rectangular format on drawing,
usually lower right corner, listing title, part numbers, mod
states, names of draughtsmen/tracers etc, dates and other
information.
titles Name of owner or operator painted on commer-
cial or GA aircraft, to be read from a distance.
TIU Time insertion unit.
TIV Tactical intervention vehicle.
TIVO US piston-engine designation: turbocharged,
direct injection, vertical crankshaft (for helicopter),
opposed.
TIW Total[ly] integrated warfare.
TIZ Traffic information zone.
TJ Turbojet.
TJAG The Judge Advocate-General.
TJF Transportable JTIDS facility (RAF).
TJRJ Turbojet/ramjet or turboramjet.
TJS Tactical jamming system.
TK 1 Turbocharger (R, G).
2 Thermal keel.
Tk Track, track angle.
TKE, TkE Track-angle error.
TKF 1 Tactical combat aircraft (G).
2 Takeoff, also TKO,Tkof.
TKM Tonne-kilometres.
TKOF, tkof Takeoff.
TKP 1 Tonne-km performed; basic measure of airline
traffic.
2 Transport clearing house (R).
TKS Chemical de-icing pastes and pumped liquid (typi-

cally 60% aqueous solution of glycol), from
Tecalemit/Kilfrost/Sheepbridge-Stokes.
TKT Sandwich of Teflon/Kapton/Teflon, uniquely
resistant even to electric arcing.
TL 1 Thermoluminescence.
2 Transition level.
3 Transmission loss.
4 Until.
5 Terminal location (Acars/AFEPS).
6 Turbinen-luftstromtriebwerke = turbojet (G).
T/L Top level.
TLA 1 Towed linear-array sonar.
2 Throttle- [or thrust-] lever angle.
TLAR 1 “That looks about right”.
2 Top-level aircraft requirements [for reliability].
TLBR Tactical laser beam recorder.
TLC 1 Trans-lunar coast.
2 Ton[ne]s lifting capacity.
3 Through-life costs.
4 Takeoff and landing chart program.
5 Tender loving care.
TLD 1 Technical-log defect.
2 Top-level domain.
TLDHS Target location designation and hand-off
system.
TLDM Royal Malaysian navy.
TLE 1 Type life extension.
2 Target-location error.
3 Treaty-limited equipment.
TLG Tail landing gear.

TLI Trans-lunar insertion.
TLLF Tactical low-level flight, or flying.
TLM Telemetry-word.
TLMC Time limits and maintenance checks.
TLO 1 Terminal learning objective.
2 Touchdown/, or takeoff/, liftoff area [also TLOF].
TLP Tactical leadership program(me).
TLR Target-locating radar.
TLS 1 Tactical, or transponder, landing system.
2 Translunar shuttle.
3 Through-life support.
4 Target level of safety.
5 Training laser system (MoD, UK).
TLSI Technical-log special inspection.
TLSS Tactical life-support system (USAF flight suit).
TLTV Towbarless tractor vehicle.
TLV 1 Transition level.
2 Threshold limit value.
TIRC TLV
644
TLWD Tailwind.
TLWS Tactical laser weapon system.
TM 1 Training memoranda.
2 Tactical missile.
3 Trade mark.
4 Ton-mile (seldom abb.).
5 Transcendental meditation, relevant to aerospace.
6 Transverse magnetic EM propagation mode.
7 Telemetry.
8 Technical manual, or memorandum.

9 Thrust magnitude (of gross thrust vector).
10 Time.
11 Transmit manifold (Awacs).
12 Timer/media (access control).
13 Thermal model.
Tm Tropical maritime.
TMA 1 Terminal manoeuvring (or control) area, ie
terminal airspace.
2 Trimethylamine.
3 Target-motion analysis.
4 Traffic management advisor (FAA).
5 Timer/media access.
TMAC Tactical medium-altitude camera.
TMB 1 Time mean bleed.
2 Turbulent mixing boundary.
TMBACA Times microwave broadband airborne cable
assembly.
TMC 1 Thrust-management computer [F adds func-
tion, S system].
2 Titanium [or titanium-aluminide metal-] matrix
composite.
3 Terminal control.
TMCR Total maintenance-cost reduction.
TMCS Technical monitoring and control[ling] system.
TMD 1 Tactical munitions dispenser.
2 Theatre missile defence.
3 Test, measure and diagnose [or measurement and
diagnostic].
4 Tactical modular display.
TME Total mission energy, normally in non-SI kWh.

TMEL Trimethyl-ethyl lead.
TMET Tethered medium Earth terminal.
TMF 1 True-mass flowmeter.
2 Thrust-management function.
TMG 1 Track made good.
2 Thermal/meteoroid garment.
3 Towing motor glider.
4 Ton-miles per gallon.
T/MGS Transportable/mobile ground station.
TMIS Technicians maintenance information system.
TML 1 Tetramethyl lead.
2 Terminal.
3 TV microwave link.
TMM Tantalum manganese-oxide metal device.
TMMC Titanium/metal-matrix composite.
TMMS TOW mast-mounted sight.
TMN True Mach number.
TMO 1 Traffic management office (AFSC).
2 Ten [nautical] miles out [from threshold].
TMP 1 Transverse-magnetized plasma.
2 Twin machine-gun pod.
3 Theatre mission planning; S adds system.
4 Test-measurement program[me].
TMPA Traffic-management program alert.
tmpr, tmprly Temporarily.
TMRC Technical-manual reference card.
TMS 1 Thrust-management system.
2 Test and monitoring station.
3 Traffic, or technical, management system, or
specialist.

4 Tactical mission system (helicopters).
5 Transformer mains supply.
TMSA 1 Trainer-mission simulator aircraft.
2 Technical Marketing Society of America.
TMT Technology management team (ASTOVL).
TMU 1 Traffic management unit (FAA).
2 Transducer matching unit (sonar).
TMW Tomorrow.
TMXO Tactical miniature crystal oscillator.
TN 1 Nuclear, thermonuclear (weapon prefix, USSR).
2 Technology need.
3 Technical note.
4 True north.
TNA 1 Truth in Negotiations Act (US Congress).
2 Training-needs analysis.
3 Thermal- neutron analysis, or activation.
4 Twin altitude.
TNAV, T-nav So-called four-dimensional navigation
system commanding three spatial dimensions and time.
TNC Terminal node controller.
TND Trace narcotics detector.
TNDCY Tendency.
TNE Tungsten nuclear engine.
TNEL Total noise exposure level; see noise.
TNF Theatre nuclear forces (S
3
or S-cubed adds ‘sur-
vivability, security and safety’).
TNGT Tonight.
TNH Turn height.

TNI 1 Total noise index; see noise.
2 Trusted network interpretation.
TNR Transfer of control message, non-radar.
TNS Technical news-sheet.
TNT 1 Trinitro-toluene; for * equivalent see yield.
2 Tragflügel neue technologie, advanced supercritical
wing (G).
TNW 1 Theatre nuclear weapon.
2 Tactical nuclear warfare.
TO, T-O 1 Takeoff.
2 Technical order.
3 Table of organization.
TOA 1 Total obligation[al] authority, sum that may be
obligated in coming FY for contracts possibly running for
many years hence.
2 Time of arrival, hence TOA/DME.
3 Usually plural, transportation operating agencies
(MAC, MSC and MTMC, US).
4 Training options analysis [software tool].
TOAA Takeoff obstacle accountability areas (study).
TO&E Table of organization and equipment.
toboggan In-flight refuelling technique in which shallow
dive is maintained to match speeds of fast tanker (if neces-
sary with spoilers or airbrakes) and slow receiver.
TOC 1 Top of climb.
2 Total operating cost (often t.o.c.).
3 Travel order card.
4 Tactical operations center (US).
5 Transfer of communication[s].
Toca Theatre operational CIS(3) architecture.

TLWD Toca
645