the Aviation Dictionary

thermograph three-D (3-D) cam
thermograph - A thermometer that continuously
records temperatures on a chart.
warning light in the cockpit. This is done by thermal
expansion of metals.
thermometer - An instrument for measuring thickness gauges - A measuring tool consisting of a
temperature.
series of precision-ground steel blades of various
thicknesses: It is used to determine the clearance or
thermonuclear action - The release of heat, light, and
separation between parts.
electromannetic - radiation from the fusion or fission of
nuclear material.
thimble - The part of a micrometer caliper that is turned
thermopile - A collection of thermocouples connected
to rotate the spindle.
in a series used to measure minute changes in thinner -A solvent used to reduce the viscosity of dope
temperature or changes in the flow of electrical current. or paint.
thermoplastic - A plastic material used in advanced third-class lever - A lever that provides a fractional
composites as a matrix material. Heat is used during disadvantage, i.e., one in which a greater force is
the forming operation. It is not a permanent shape, required than the force of the load lifted. For example,
however, if heated again it will soften and flow to form if a muscle pulls with a force of 1,800 Ibs. in order to
another shape (Plexiglas windshield). lift a 100 Ib. object, a mechanical advantage of 100/1.800
is obtained. This is a fractional disadvantage, since it is
thermoplastic material - A resin-bascd plastic material
less than 1.
that can be softened by heat and cooled many times
without losing its tensile strength.
thixotropic - In composites, an agent used to thicken a
resin system without adding weight. Makes the resin
thermoplastic resin - A resin material that softens with
system less dense. Thixotropic agents include chopped
the application of heat. Most aircraft windshields and
fibers, microballons, and fiber flox. Some agents give
side windows are made of this material.
more strength than others.
thermosafety discharge indicator - A red blowout disc
thirotropic agent - A added to a resin to
located on the outside of an aircraft fuselage or engine
increase its resistance to flow.
nacelle that blows out to vent a cylinder of
high-pressure gas in the event of an overpressure thread - 1. Projecting helical grooves cut around the
condition caused by heat.
outside of a bolt, fitting, or pipe and on the inside of a
bolt or fitting. 2. A very fine strand of linen, cotton, or
thermoset - A plastic material used in advanced
other material used to make yam or fabric.
composites as a matrix material. Heat is used to form
and set the part permanently. Once cured, it cannot be thread chaser - A tool used to remove contamination
reformed by applying heat. Most composite structural from a threaded device.
components are made of thermoset plastics.
thermosetting material - A plastic material that
remains hard once it is hardened by chemical means or
by heat and pressure.
thermosetting resin - A widely used resin that usually
sets by chemical means and maintains its hardness
even when heat is applied.
thermosphere - The area of the atmosphere above the
mesosphere that has little practical influence over the
weather. The thermosphere is marked by generally
increasing temperature with altitude.
thermostat - A device that functions to establish or
maintain a desired temperature produced by a heater or
air-conditioning system.
thermostatic bypass valve - A temperature-sensing
valve in an engine oil cooler, used to direct the oil
either through the core of the cooler or around the
inside of the cooler shell to maintain the proper oil
temperature.
thermoswitch fire detector - A device that closes an
electrical contact in the presence of heat, illuminating a
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thread gauge - A gauge with a series of V-notches cut
along one edge. Used to check the number of threads,
or the pitch, of a screw or bolt.
thread insert - An internally threaded bushing designed
to be molded in or inserted into soft or brittle materials
to increase their strength and minimize the wear of the
threaded assembly.
thread pitch - The distance from the peak of one thread
to the peak of the next thread on a screw, bolt, or other
thread fitting. Also referred to as a screw pitch gauge.
thread plug gauge - A golno-go type gauge to be
screwed into internal threads.
thread ring gauge - A ring-type gauge used for
checking external threads.
three-axis autopilot - An automatic flight control
system that controls an aircraft about all three axes.
three-D (3-D) cam - Part of a linkage system, this
multi-labeled cam can rotate and move up and down to
allow a cam follower riding on its surface to seek an
infinite number of positions. Used to miniaturize
linkage systems such as in fuel controls.