the Aviation Dictionary

by an absorbent developer. A crack appears as a line on
the surface of the developer.
dynafocal engine mount - A mount that attaches an
aircraft engine - onto the airframe in which the extended
center line of all of the mounting bolts would cross at
the center of gravity of the engine and propeller
combination.
dynamic - Continuous review, evaluation, and change
to meet demands.
dynamic balance - The condition that exists in a
rotating body in which all of the rotating forces are
balanced within themselves and no vibration is
produced by the body in motion.
dynamic braking - A method of slowing the rotation of
equipment driven by an electric motor. Braking is
accomplished by disconnecting electrical power from
the motor and replacing it with a resistance load. The
inertia of the m~tor/equipment causes the motor to
become a generator and the resistance absorbs the
electrical output of the motor and thus resists and slows
the rotation.
dynamic damper - A counterweight on the crankshaft
of an aircraft engine. It is attached in such a way that it
can rock back and forth while the shaft is spinning and
absorb dynamic vibrations. In essence, it changes the
resonant frequency of the enginelpropeller
combination.
dynamic factor - The ratio between the load carried by
any part of an aircraft when accelerating and the
corresponding basic load.
dynamic load - The effective weight of an aircraft. It is
the actual weight of the aircraft multiplied by the load
factor (G-load). When an aircraft is sitting on the ramp,
the load factor is one and the dynamic load equals the
weight of the aircraft. In flight, if the aircraft is
experiencing a load factor of two (as it would be if in a
level 60" bank turn) the dynamic load would be twice
the actual weight of the aircraft.
dynamic microphone - A device used to convert
acoustic pressure waves into electrical waves.
Incoming sound impinges a movable diaphragm that
has a coil of wire on it. The coil is in a magnetic field
and its movement produces an electrical signal that
correlates to the sound.
dynamic pressure - The product 'I2 p v2, where p is the
density of the air and V is the relative speed of the air.
dynamic restrictions - Those restrictions imposed by
the local facility on an "as needed" basis to manage
unpredictable fluctuations in traffic demands.
dynamic rollover - The tendency of a helicopter to
continue rolling when the critical angle is exceeded, if
one gear is on the ground, and the helicopter is pivoting
around that point.
Aircraft Technical Book Company
P.O. Box 270
Tabernash, CO 80478
http://w.ACTechbooks.com
dynafocal engine mount . Dzus fastener
dynamic stability - The property of an aircraft that
causes it, when disturbed from straight and level flight,
to develop forces or moments that restore the original
condition of straight and level.
dynamometer - An instrument used to measure torque
force or power.
dynamotor - A machine with two windings on a single
armature that simultaneously operates as a motor with
one of the windings - and as a - generator with the other.
The armature windings are usually different so that the
voltage on the generator side is different from the
voltage on the motor side and the machine acts as a
rotary transformer.
dynatron effect - The area of operation in a tetrode
electron tube where plate current decreases as plate
voltage increases. This effect is caused by secondary
electrons to the screen grid.
dyne - A unit of force. Dyne is the amount of force
required to accelerate one gram of mass one centimeter
per second squared. In science, the term is slowly
becoming obsolete.
dynode - The elements in a multiplier tube that emit
secondary electrons.
Dzus fastener - A patented form of cowling fastener in
which a slotted stud is forced over a spring steel wire
and rotated to lock the wire in a cam.