the Aviation Dictionary

power brake control valve . prearranged coordination
power brake control valve - A pressure regulator
between the aircraft hydraulic system and the brake
cylinders. The amount of pressure applied to the brakes
is directly proportional tothe force the pilot puts on the
brake pedals.
power control system - A control system in which the
normal movement of the controls iaassisted by the use
of hydraulic or pneumatic actuators to reduce the
amount of force the pilot must apply.
power density - In radar, the amount of radar energy
per cross-sectional area.
power enrichment system -A carburetor subsystem for
a reciprocating engine that increases the fuel mixture
when the engine is operating at full power.
power factor - The ratio of the resistance of an
electrical circuit to the circuit impedance measured by
a wattmeter.
power frequency - Frequency of AC electricity used for
heat and light. Commercial power frequency in the
U.S. is 60 Hz, and the aircraft power frequency is 400
Hz.
power lever -- The cockpit lever that connects to the fuel
control unit for scheduling fuel flow to the combustor.
Also referred to as power control lever or throttle.
power lever angle (PLA) - A protractor on the fuel
control showing movement of the power lever in
degrees.
power loading - The ratio of an aircraft's maximum
gross weight to the brake horsepower produced by the
engines.
power overlap - The time in which two or more
cylinders of an engine are simultaneously on the power
stroke. The more cylinders an engine can have on the
power stroke at one time, the greater the power overlap
and the smoother the operation.
power pump - A hydraulic pump driven by the aircraft
engine or by an electric motor.
power recovery turbine (PRT) - A power recovery
device used on the Wright R-3350 engine. The exhaust
gases spin a series of small turbines that are clutched to
the crankshaft by fluid-coupling devices.
power section - That portion of a radial engine on
which the cylinders are mounted.
power stroke - The movement of the piston of an
aircraft reciprocating engine when the piston is forced
down by the expanding gases. This is the only time
work is accomplished by the engine.
power supply - The part of an electronic circuit that
supplies the filament and plate voltages for the
operation of the circuit.
power transformer - An electrical power supply
transformer that changes voltage to that needed for the
operating unit.
-
power turbine - A turbine rotor connected to an output
shaft but not connected to the comDressor. Also
referred to as fiee power turbine.
powered-lift - A heavier-than-air aircraft capable of
vertical takeoff, vertical landing, and low speed flight
that de~ends vrinci~allv on engine-driven lift devices
A . -
or engine thrust for lift during these flight regimes and
on non-rotating airfoil(s) for lift during horizontal
flight.
powered parachute - A powered aircraft comprised of
a flexible or semi-rigid wing connected to a fuselage so
that the wing is not in position for flight until the
aircraft is in motion. The fuselage of a powered
parachute contains the aircraft engine, a seat for each
occupant, and is attached to the aircraft's landing - gear. -
powerplant - The complete installation in an aircraft of
the engine, propeller, and all of the accessories and
controls needed for its proper operation.
powerplant technician - A person who holds a
certificate from the FAA authorizing him or her to
perform maintenance or inspection on the powerplant,
including the propeller, of certificated aircraft.
practical test standards (PTS) -An FAA published list
of standards that must be met for the issuance of a
particular pilot certificate or rating. FAA inspectors
and designated pilot examiners use these standards
when conducting pilot practical tests and flight
instructors should use the PTS while preparing
applicants for practical tests.
practice instrument approach - An instrument
approach procedure conducted by a VFR or an IFR
aircraft for the purpose of pilot training or proficiency
demonstrations.
Pratt truss - A truss
structure in which the
vertical members
carry only compressive
loads, and
ihe diagonal
members carry only tensile loads. A Pratt truss is used
for most fabric-covered wings.
preamplifier - An electronic circuit component that
amplifies an extremely weak input signal to a value
strong enough to be used in other amplifiers.
prearranged coordination - A standardized procedure
that permits an air traffic controller to enter the
airspace assigned to another air traffic controller
without verbal coordination. The procedures are
defined in a facility directive that ensures standard
separation between aircraft.
Aircraft Technical Book Company
P.O. Box 270
Tabernash, CO 80478
http:llwww.ACTechbooks.com