Tulca aviation Dictionary

Alpha Bismillah Charlie Delta Echo
Foxtrot Golf Hotel insaallah Juliett Kilo Lima Mike November Oscar Piaggio Quebec Romeo Sierra Turks Uniform Victory Water X-ray Yankee Zulu Main Page

P FACTOR

P factor A tendency for an aircraft to yaw to the left due to the descending propeller blade on the right producing more thrust than the ascending blade on the left. This occurs when the aircraft s longitudinal axis is in a climbing attitude in relation to the relative wind. The P factor would be to the right if the aircraft had a counter-clockwise rotating propeller.

P time Proposed Departure Time. The time a scheduled flight will depart the gate (scheduled operators) or the actual runway off time for nonscheduled operators. For EDCT purposes, the ATCSCC adjusts the P time for scheduled operators to reflect the runway off times.

pack carburizing A heat treatment method for case-hardening steel parts in which the parts are packed in the carburizing compound, placed into a drum, and heated to a temperature of about 1500 F.

package A complete assembly unit.

packing The hydraulic seal that prevents fluids from leaking between two surfaces that move in relation to each other.

packing ring An O-ring used to confine liquids or gases, preventing their passing between a fixed body and a movable shaft.

paint An aircraft finish that consists of pigments suspended in a solvent-type vehicle. The paint protects and improves the appearance of the aircraft.

paint drier Any substance added to paint to improve its drying properties.

paint stripper A chemical material that softens the paint film and loosens its bond to the metal, thus enabling the paint to be easily wiped or washed away.

pal nut A thin, pressed-steel check nut screwed down over an ordinary nut to prevent it from coming loose or backing off.

palladium A metallic element with a symbol of Pd and an atomic number of 46.

pan A hollow depression or shallow metal object used to hold oil.

pancake landing An aircraft landing procedure in which the aircraft is on an even plane with the runway. As the aircraft reduces speed and lift, it drops to the ground in a flat or prone attitude.

panel Any separate or distinct portion of an aircraft surface.

pan-head screw A machine screw or sheet metal screw that has a large, slightly domed head.

pan-pan-pan The international radio-telephony urgency signal. When repeated three times, indicates uncertainty or alert followed by the nature of the urgency.

pants Streamlined airplane wheel covers.

paper electrical capacitor An electrical component that uses two strips of metal foil for its plates and strips of waxed paper as its dielectric.

parabola A plane curve equally distant from a fixed point and a fixed line.

parabolic light reflector A light reflector, such as a light bulb, with a curved or parabolic surface.

parabolic microphone A sensitive, highly directional microphone mounted at the focal point of a parabolic dish capable of picking up sound from long distances.

parachute A device used or intended to be used to retard the fall of a body or object through the air.

parachute A large cloth device shaped like an umbrella used to retard the fall of a body or object through the air.

par-al-ketone A heavy, waxy grease used to protect control cables and hardware fittings from corrosion on seaplanes.

parallax Apparent displacement of an object if first viewed from one position and then from another.

parallax The apparent change in relationship of two objects when viewed from different locations not in line with the objects.

parallel 1. Lines that run in the same direction and will never meet or cross because the distance between them is constant. 2. Having more than one path for electron flow between the two sides of the electron source.

parallel access In computers, a term used to describe a method of accessing data simultaneously, or all data at the same time.

parallel circuits Two or more complete circuits connected to the same two power terminals.

parallel ILS approaches Approaches to parallel runways by IFR aircraft that, when established inbound toward the airport on the adjacent final approach courses, are radar separated by at least 2 miles.

parallel lines Two or more lines extending in the same direction and at the same distance apart at all points.

parallel MLS approaches See parallel ILS approaches.

parallel of latitude Any of the imaginary lines on the surface of the Earth parallel to the equator and representing degrees of latitude on the Earth s surface.

parallel offset route A parallel track to the left or right of the designated or established airway/route. Normally associated with Area Navigation (RNAV) operations.

parallel operation In computers, an operation that moves information simultaneously over several lines as opposed to serially, which moves information one bit at a time over a single line. Also used to describe an operation using more than one processor simultaneously.

parallel resonant electrical circuit A circuit made up of an inductor and a capacitor connected in parallel. If a circuit is resonant, the inductive reactance and the capacitive reactance are equal at a particular frequency. Also referred to as a tank circuit

parallel runways Two or more runways at the same airport whose centerlines are parallel. In addition to runway number, parallel runways are designated as L (left) and R (right) or, if three parallel runways exist, L (left), C (center), and R (right).

paralleling Controlling the output of more than one generator in order to share a load equally. This involves matching the voltage outputs, the frequency (of AC generators) and the phase relationship of the AC current (of AC generators).

paralleling generators An operational procedure in which the output voltages of multi-engine aircraft electrical system generators are adjusted to share the electrical load equally. This involves matching the voltage outputs, the frequency (of AC generators) and the phase relationship of the AC current (of AC generators).

paramagnetic material A material that becomes magnetic when placed in a strong magnetic field and retains some level of magnetic property as long as the strong magnetic field is present. However, when the strong magnetic field is removed, the material loses its magnetic properties.

parameter A quantity or constant whose value varies with the circumstances of its application.

parasite drag That part of total drag created by the form or shape of airplane parts.

parasite drag Drag caused by the friction of the air flowing over a body. Parasite drag increases as airspeed increases.

parasol wing airplane An airplane having one main supporting surface mounted above the fuselage on cabane struts.

parcel A volume of air, small enough to contain uniform distribution of its meteorological properties, but large enough to remain relatively self-contained and respond to all meteorological processes.

Parco lubrizing Anti-friction coatings that contain solvent-based suspensions of solid lubricants instead of a coloring pigment.

Parkerizing A method of treating metal parts by immersing them in a solution of phosphoric acid and manganese dioxide. Used to protect the surface from rusting.

Parker-Kalon (PK) screws Self-tapping sheet metal screws. PK screws are made of hardened steel, and have sharp, coarse threads that combine drilling, tapping and fastening.

parking brake A mechanical or hydraulic brake system used to prevent an aircraft from moving from its parked position.

part number An identification number assigned to a particular part or assembly by the manufacturer.

part power trim check The act of trimming the engine with the power lever against a trim stop or rig pin, then checking the EPR or N1 speed against a trim curve for ambient conditions. If the correct values are not present, adjustment of the fuel control, referred to as trimming, is required.

partial obscuration Denotes that 1/8th or more of the sky, but not all of the sky, is hidden by surface-based (excluding precipitation) phenomena in the atmosphere.

partial panel Controlling the airplane without the benefit of all instrumentation due to failure of one or more instruments in flight. Pilots are required to demonstrate basic attitude instrument flying on partial panel and are also required to fly a partial panel instrument approach during the practical test for the instrument rating.

partial pressure The gases that make up the atmosphere each exert a partial pressure. When all of the partial pressures are added together, they equal the total atmospheric pressure.

partial-panel flight Instrument flight without vacuum-powered gyroscopic instruments. Remaining instruments would be the altimeter, airspeed indicator, turn coordinator, vertical speed indicator, and magnetic compass.

particle A small piece of any substance or matter.

particulates Very small liquid or solid particles in the atmosphere. When suspended in the atmosphere, they are called aerosols.

parting agent In composites, a lubricant used to prevent the part from sticking to the mold.

parting film In composites, a layer of thin plastic to prevent bagging materials from sticking to the part. It can be perforated to vent excess resin. It is removed after cure. Can be used instead of peel ply.

parts manufacturing approval (PMA) Approval by the Federal Aviation Administration to design and manufacture aircraft replacement parts for sale directly to the public.

pascal A metric unit of pressure. Equals one newton per square meter.

Pascal s law A basic law of fluid power that states that pressure in an enclosed container is transmitted equally, undiminished to all points of the container, and acts at right angles to the enclosing walls.

passenger mile An airline statistic used to track utilization of aircraft. One passenger mile is equal to one passenger traveling one mile. Five passengers traveling 100 miles would equal 500 passenger miles.

passivating A treatment of corrosion-resistant steels after welding. The purpose is to remove iron from the surface and expose more chromium, allowing a chrome rich oxide film to form and protect the surface from corrosion.

passive electrical circuit An electrical circuit that does not contain any source of electrical energy such as a battery or generator. Such circuits would include only passive electronic components. One example would be a filter (consisting of inductors and capacitors) in a receiver circuit that is powered only by the received signal.

passive electrical component An electrical component, such as resistor, capacitor or inductor, that produces no gain in the circuit.

passive satellite A passive satellite reflects received radio signals back to Earth without amplification.

passive sonar A device for detecting the presence of an object by the sound it emits in water. Sonar stands for sound navigation ranging.

passive video Refers to segments of video that are simply watched by the students.

patch A small piece of material used for strengthening, reinforcing, or covering a hole or weak spot in a structure.

pattern 1. A model, guide, or plan used to form or make things. 2. The flight pattern an aircraft must follow when approaching the airport for landing and when leaving the airport after taking off. Aircraft operating from the airport must follow the same flight pattern in order to reduce the danger of an in-flight collision.

pawl A pivoted stop in a mechanical device that allows motion one way but prevents it in the opposite direction. It is commonly used in a ratchet mechanism.

payload That part of the useful load of an aircraft that is over and above the load necessary for the operation of the vehicle. The term used for passengers, baggage, and cargo.

P-channel field effect transistor (FET) Similar to an N-channel FET but with the types of material reversed. Control is achieved by the application of positive voltage to the gate.

peak alternating current The greatest amount of current that flows in one alternation of alternating current. The greatest amount of deviation from the zero line of deviation as measured on an oscilloscope.

peak inverse voltage The maximum voltage that can be applied safely to an electron tube in the direction opposite to normal current flow.

peak value The maximum value of AC or voltage measured from the zero reference line.

peak wind The maximum wind speed since the last hourly observation.

peak-to-peak voltage Absolute value of the difference between the maximum positive and maximum negative values of an AC waveform.

pedestal grinder A grinder mounted on a pedestal and stands on the floor of the shop.

peel ply In composites, a layer of fabric used in manufacturing to vent excess resin up into the bleeder material. It prevents bagging materials from sticking to the part, and it leaves a very finely etched surface for painting. It is removed after cure.

peel strength In composites, the amount of strength it takes a part to resist the stress applied from peeling apart of two plies.

peen To round over or flatten the end of a shaft or rivet by light hammer blows.

peened surface A marked surface as from an impact with a blunt instrument. Caused by careless handling or concentrated load sufficient to permanently deform the metal surface.

pencil compass A drawing instrument that uses a pencil to draw circles or arcs.

pendular action In rotorcraft, the lateral or longitudinal oscillation of the fuselage due to it being suspended from the rotor system.

pendulum A body suspended from a fixed point but that is free to swing back and forth or oscillate.

pendulum valves Gravity-operated air valves over the discharge ports of a pneumatic gyro horizon s rotor housing. When the gyro tilts, the pendulum valves change the airflow from the housing and cause a precessive force that erects the gyro.

pentagrid converter A five-grid electron tube that serves as a mixer, local oscillator, and first detector in a superheterodyne radio receiver.

pentode A five-element vacuum tube or electron tube containing five electrodes: cathode, plate, control grid, suppressor grid, and screen grid.

perceptions The basis of all learning. Perceptions result when a person gives meaning to external stimuli or sensations. Meanings, which are derived from perceptions, are influenced by an individual s experience and many other factors.

percussive welding A resistance welding process in which an electrical arc and pressure are simultaneously applied across the materials being welded.

perfect dielectric A dielectric that has no conductivity. A perfect dielectric is an insulator that returns all of the used energy to establish an electric field when the electrical field is removed.

perforate To create a hole in a material such as paper.

perforated parting film or release film In composites, a thin layer of plastic film used to prevent bagging materials from sticking to the part. The perforations allow some resin to flow through small holes in the plastic. Used in the same way as peel ply.

performance chart A chart detailing the aircraft performance that can be expected under specific conditions.

performance envelope A range of flight conditions and performance for which an aircraft has been designed and tested for. Flying an aircraft outside these parameters is done so at the risk of unknown consequences.

performance number The anti-detonation rating of a fuel that has a higher critical pressure and temperature than isooctane. Isooctane is used as the reference.

performance-based objectives A statement of purpose for a lesson or instructional period that includes three elements: a description of the skill or behavior desired of the student, a set of conditions under which the measurement will be taken, and a set of criteria describing the standard used to measure accomplishment of the objective.

period The time required for one cycle of AC.

period oscillation The amount of time needed to complete one cycle of an oscillation.

periodic event Any regularly repeated event.

periodic inspection Any regularly repeated inspection. An annual or 100-hour inspection of an aircraft is a periodic inspection.

periodic table of chemical elements A table of chemical elements arranged in the order of their atomic numbers.

periodic vibration A vibration that has a regularly recurring resonance.

peripheral equipment Devices that provide support for primary units of equipment. In computers, peripheral equipment would include hard disk drives, floppy drives, modems, and CD ROM drives.

periphery The outside of a circular or curved figure.

Permalloy An alloy of iron and nickel used in the manufacture of permanent magnets.

permamold crankcase An engine crankcase that has been pressure molded in a permanent mold. It is thinner and denser than a sand-cast crankcase.

permanent ballast A weight that has been permanently installed in an aircraft to bring its center of gravity into allowable limits

permanent echo Radar signals reflected from fixed objects on the Earth s surface; e.g., buildings, towers, terrain. Permanent echoes are distinguished from ground clutter by being definable locations rather than large areas. Under certain conditions they can be used to check radar alignment.

permanent magnet A ferrous metal or alloy of ferrous metals usually containing nickel and cobalt, in which the magnetic domains are aligned, and tend to remain aligned. Lines of magnetic flux join the poles of the permanent magnet so that an electrical current can be generated when these lines of flux are cut by a conductor.

permanent magnet speaker A speaker that uses a small permanent magnet to provide the magnetic field for the voice coil.

permanent mold A mold that can be used repeatedly to produce molded parts. Usually constructed of metal or ceramic materials.

permanent set A mechanical deformity caused by excessive stress placed on a material.

permeability The ability of a material to accept and concentrate lines of magnetic flux.

Perminvar Special alloy used for permanent magnets.

persistence In cathode-ray tubes (CRTs), the length of time the phosphorescent glow remains after the electron beam has moved on.

persistence forecast A weather prediction based on the assumption that future weather will be the same as current weather.

person An individual, firm, partnership, corporation, company, association, joint-stock association, or governmental entity. It includes a trustee, receiver, assignee, or similar representative of any of them.

personal checklists To help students determine if they are prepared for a particular flight, encourage them to create personal checklists that state their limitations based on

such factors as experience, currency, and comfort level in certain flight conditions.

personal computer-based aviation training devices (PCATDs) A computer based flight simulator that has been authorized by the FAA to be used for a small portion of the instrument time required for instrument ratings. Uses cathode ray tube computer monitor for display.

personality A set of personal traits and characteristics of an individual.

perspective The technique of representing the spatial relationship of objects as they appear to the eye.

petroleum A substance containing chemical energy and used as a fuel for most of engines. It is a natural hydrocarbon product that was at one time plant or animal life, but was buried under billions of tons of Earth. It is obtained as a liquid from deep wells or from oil shale.

petroleum-zinc-dust compound A material used inside an aluminum terminal lug when swaging the lug onto aluminum wire. The zinc dust abrades the oxides from the aluminum, and the petrolatum prevents its reformation.

pH A measure of acidity and alkalinity of a solution on a 14 point scale where a value of 7 represents neutrality. 1 indicates maximum acidity and 14 indicates maximum alkalinity.

phantom line Thin lines made up of alternating long dashes and two short dashes. Used to show an alternate position or a missing part in a mechanical drawing.

phase 1. The time difference between an event in the voltage waveform and the equivalent event in the current waveform in an AC circuit. 2. A section or a distinguishable part of a maintenance program or inspection.

phase angle The number of degrees of generator rotation between the time the voltage passes through zero and the time the current passes through zero in the same direction.

phase change A change of state.

phase inverter An electronic device that changes the phase of a signal by 180 .

phase lock A method of modulating the phase, condition, or state of one electronic oscillating device so it will exactly follow that of another oscillating device.

phase modulation A method of modulating the carrier wave of a radio signal. The phase angle is changed relative to voltage changes of the input signal.

phase shift The difference in time between similar points of an output and an input electrical wave form.

phenol-formeldehyde resin A thermosetting plastic resin reinforced with cloth or paper to make molded plastic objects.

phenolic material A thermosetting resin or plastic made by condensation of a phenol with an aldehyde and used for molding and insulating.

phenolic plastic Plastic thermosetting phenolic-formaldehyde resin material, reinforced with cloth or paper.

phenolic resin A thermosetting resin produced by the condensation of an aromatic alcohol with an aldehyde, particularly of phenol with formaldehyde.

Phillips-head screw A recessed-head screw designed to be driven with a cross-pointed screwdriver whose point has two distinct tapers and a blunt point. The Reed and Prince is another cross-point driver but it has straight sides, only one taper, and tapers to a point.

P
honetic alphabet

phonetic alphabet Standard words (lexicon) and combinations of words used for each of the letters in the alphabet during radio transmission. Examples of standard phonetic alphabet now in use are:

Alpha Bravo Charlie Delta Echo Foxtrot Golf Hotel india Juliett Kilo Lima Mike November Oscar Papa Quebec Romeo Sierra Tango Uniform Victory Water X-ray Yankee Zulu

phosgene A colorless gas with an unpleasant odor produced when Refrigerant-12 is passed through an open flame. Causes severe respiratory irritation.

phosphate ester-base hydraulic fluid A synthetic, fire-resistant hydraulic fluid used in high-pressure hydraulic systems of modern jet aircraft. It is identified by the specifications MIL-H-8446.

phosphate film A dense, insoluble, inorganic film deposited on the surface of a metal treated with a conversion coating.

phosphor coating A coating for the numerals and pointers on instrument dials. The coating glows when excited with ultraviolet light rays.

phosphorescent paint A paint that absorbs energy from natural light or from ultraviolet light and which continues to glow after the natural light is removed.

phosphoric acid etchant That constituent of a conversion coating that microscopically roughens the surface of the metal being treated and deposits a phosphate film.

phosphorus A chemical element with a sign of P and an atomic number of 15.

photo cell An electronic device that becomes conductive or produces a voltage when struck by light.

photo reconnaissance Military activity that requires locating individual photo targets and navigating to the targets at a preplanned angle and altitude. The activity normally requires a lateral route width of 16NM and altitude range of 1,500 feet to 10,000 feet AGL.

photocathodes An electrode within an electron tube that releases electrons after it has been exposed to light.

photochemistry That branch of chemistry having to do with the effects of light on chemical reactions.

photoconductive cell A photoelectric cell that changes its resistance according to the amount of light exposure. Photoconductive cells are used in photographic light meters.

photodiode A semiconductor diode that can conduct in its reverse direction when light is shown on its junction.

photoelectric characteristics The changes (positive or negative) produced in the electrical characteristics of a material when exposed to light.

photoelectric material Any element that emits electrons when exposed to light. Elements such as alkaline metals, cesium, lithium, and rubidium are photoelectric.

photoelectricity Electricity produced by the action of light on certain photoemissive materials.

photoemissive characteristic The trait of a material to emit electrons when exposed to light.

photoemissivity The tendency of a material to emit electrons when exposed to light.

photon A particle of radiant energy.

photonegative characteristics The characteristics of a material increasing in resistance when exposed to light.

photosensitive The property of emitting electrons when struck by light. See also photoemissive.

photothyristor A semiconductor device that is responsive to visible or infrared radiant energy. May or may not include mounting hardware and/or heat sink.

phototransistor A transistor that can be forward-biased into conduction by applying light to its emitter-base junction.

photovoltaic cell A solid-state electrical component that produces a voltage when exposed to light.

phugoid oscillations Long-period oscillations of an aircraft around its lateral axis. It is a slow change in pitch accompanied by equally slow changes in airspeed. Angle of attack remains constant, and the pilot often corrects for phugoid oscillations without even being aware of them.

physical needs Needs that encompass the necessities for survival, which include food, rest, exercise, and protection from the elements. Until these requirements are satisfied, students cannot fully concentrate on learning.

physical organism A perception factor that describes a person s ability to sense the world around them.

physical properties Those properties of a body that can be determined by methods other than chemical, including weight, strength, and hardness.

physical tables Tables that list the physical properties and characteristics of materials.

physics A natural science that deals with matter and energy and their interaction in the various fields of mechanics.

pi (π) A mathematical constant representing the ratio between the circumference and diameter of a circle with a value of approximately 3.1415927. Represented by the Greek letter π.

pi filter A network consisting of two capacitors and an inductor net arranged in the form of the Greek letter pi (π). It is essentially a capacitor-input filter followed by an L-filter.

piano hinge A continuous metal hinge consisting of hinge bodies attached to both fixed and movable surfaces. A hard steel wire connects the two bodies and serves as the hinge pin.

pickling 1. The treatment of a metal surface with acid to remove surface contamination. 2. Preparing an aircraft engine for longtime storage.

pick-off That portion of a device or system that removes a signal from a sensor.

pico One-millionth of a millionth (0.000,000,000,001) of a unit.

picofarad (pf or μμf) One-millionth (0.000001) of a microfarad.

pictorial diagram A diagram used by maintenance technicians. It can be either a line drawing, sometimes with shading to emphasize shapes, a picture of a part enlarged to show detail, or a photograph of a piece of equipment, illustrating the overall appearance of a unit, its shape, relative sizes and location of components, interconnecting wires, cables, etc.

pictorial drawing A drawing consisting of pictures that shows an object as it appears to the eye.

pie chart A graph drawn in the shape of a circle and divided into pieces like a pie to convey data or proportions.

piezoelectric crystal A thin crystal that produces a voltage when distorted. Used in strain gauges and vibration detectors. Also produces vibration when a voltage is applied. Used in ultrasonic transducers.

piezoelectric effect The property of certain crystals that enables them to generate an electrostatic voltage between opposite faces when subjected to mechanical pressure. Conversely, the crystal will expand or contract if subjected to a strong electrical potential.

piezoelectric transducer An electrical device that enables a mechanical movement to generate an electrical signal.

piezoelectricity Electricity produced when certain crystalline materials such as quartz are subjected to mechanical pressure.

pig iron Crude iron, reduced from the iron ore in a blast furnace.

pigment A powder or paste mixed with a paint finish to give the desired color.

pigtail A piece of wire that sticks out of a component and allows the component to be installed or tied.

pilot 1. A person licensed to operate an airplane, ship, or balloon in flight. 2. A part that guides another part in its movement.

pilot balloon In weather, a small balloon that is released and tracked in order to determine wind direction and speed.

pilot balloon observation In weather, a method of determining wind direction and speed by tracking a pilot balloon. Also referred to as a pibal.

pilot briefing A service provided by the FSS to assist pilots in flight planning. Briefing items can include weather information, NOTAMs, military activities, flow control information, and other items as requested.

pilot chute A small parachute attached to the canopy of the main parachute. The pilot chute pulls the main canopy out of the parachute pack so that it can open.

pilot controlled lighting (PCL) Radio control of lighting is available at selected airports to provide airborne control of lights by keying the aircraft s microphone. The control system consists of a 3-step control responsive to 7, 5, and/or 3 microphone clicks. The 3-step and 2-step lighting facilities can be altered in intensity. All lighting is illuminated for a period of 15 minutes (except for 1-step and 2-step REILs which can be turned off by keying the mike 5 or 3 times, respectively).

Suggested use is to always initially key the mike 7 times; this assures that all controlled lights are turned on to the maximum available intensity. If desired, adjustment can then be made, where the capability is provided, to a lower intensity (or the REIL turned off) by keying the mike 5 and/or three times. Approved lighting systems can be activated by keying the mike as indicated below:

KEY MIKE ( ) times within 5 seconds FUNCTION:

7 times within 5 seconds Highest intensity available

5 times within 5 seconds Medium or lower intensity (Lower REIL or REIL-Off)

3 times within 5 seconds Lowest intensity available (Lower REIL or REIL-Off)

Due to the close proximity of airports using the same frequency, radio controlled lighting receivers can be set at a low sensitivity requiring the aircraft to be relatively close to activate the system. Consequently, even when lights are on, always key mike as directed when overflying an airport of intended landing or just prior to entering the final segment of an approach. This will assure the aircraft is close enough to activate the system and a full 15 minutes lighting duration is available.

pilot error An action or decision made by the pilot that was the cause of, or contributing factor, which led to an accident or incident. This definition also includes failure of the pilot to make a decision or take action.

pilot hole A small hole drilled or punched in sheet metal that is smaller than the bolt or rivet to be used. The pilot hole serves as a guide for final drilling.

pilot in command The person who: (1) Has final authority and responsibility for the operation and safety of the flight; (2) Has been designated as pilot in command before or during the flight; and (3) Holds the appropriate category, class, and type rating, if appropriate, for the conduct of the flight.

pilot light Electrical equipment light indicating power is on.

pilot proficiency award program WINGS is the FAA Pilot Proficiency Award Program designed to encourage general aviation pilots to continue their training. The objective is to provide pilots with the opportunity to establish and participate in a personal recurrent training program. WINGS is an excellent opportunity for pilots to reevaluate their flight proficiency and knowledge. WINGS is open to all pilots holding a recreational certificate or higher with a current medical certificate, when required. After pilots log three hours of dual instruction under the program and attend at least one FAA sanctioned safety seminar, they are eligible to receive and wear a distinctive set of WINGS. They will also receive a certificate of completion. Each twelve-month interval after earning the first set of WINGS, the pilot will be eligible for more WINGS. CFIs can substitute completion of a flight instructor refresher clinic or renewal program for the safety seminar. In addition, they can satisfy the flying portion of the first three phases by providing the

instruction for three WINGS candidates ― a minimum of nine hours of instruction.

pilot weather report (PIREP) A report, generated by pilots, concerning meteorological phenomena encountered in flight.

pilotage Navigation by visual reference to landmarks.

pilot-in-command The person who has final authority and responsibility for the operation and safety of the flight; has been designated as pilot in command before or during the flight; and holds the appropriate category, class, and type rating, if appropriate, for the conduct of the flight.

pilot-induced oscillation (PIO) Rapid oscillations caused by the pilot s over-controlled motions. PIOs usually occur on takeoff or landings with pitch sensitive gliders and in severe cases can lead to loss of control or damage.

pilot s discretion When used in conjunction with altitude assignments, pilot discretion means that ATC has offered the pilot the option of starting climb or descent whenever the pilot wishes and conducting the climb or descent at any rate. The pilot can temporarily level off at any intermediate altitude. However, once the pilot has vacated an altitude, the pilot cannot return to that altitude.

pilot s telephone weather answering service (PATWAS) A recorded, continuous telephone briefing, forecast for the local area within a 50 nautical mile radius of the station. No longer provided by Flight Service Stations, has been replaced by the Telephone Information Briefing Service (TIBS), an automated service.

pin A straight cylindrical or tapered fastener designed to perform an attaching or locating function.

pin contacts Electrical connector contacts, called male contacts, in the form of a set of metal pins in one-half of a connector. These pins fit into sockets, called female contacts, in the other half of a connector.

PIN diode A junction diode with a region of intrinsic semiconductor between layers of n-silicon and p-silicon.

pin holes In composites, small holes caused by the mold used.

pin jack A female receptacle that will accept and hold a small metal pin attached to the end of a wire or a test lead. Pin jacks are used on test equipment such as multimeters.

pin punch A long punch with straight sides. Used to remove bolts and rivets from tight-fitting holes. See also punch.

pin spanner A semi-circular wrench with pins that fit into holes around the edge of a circular nut.

pinch-off voltage In electronics, the reverse bias that must be applied to an FET to reduce source-drain current to a specific value.

pinhole A tiny defect in a finish caused by a bubble in the paint film.

pinion A small cogwheel whose teeth fit into a larger gear.

pinion gear A small gear on a shaft driven by either a sector gear or a toothed rack.

pinked edge The edge of a fabric material that has been cut into a series of small V s to prevent the material from unraveling.

pinked-edge fabric A fabric material with an edge that has been cut into a series of small V s to prevent the material from unraveling.

pinked-edge tape A surface tape whose edges have been cut into small V s.

pinking shears Scissors that cut fabric in a series of small V s.

pinouts Diagrams that show the positions of and name the functions of the connections to the pins of an electronic device.

pint A measure unit of volume equal to 1/2 quart, l/8 gallon, 28.875 cubic inches, or approximately 4.73 x 10-4 cubic meter.

pipe threads The tapered threads on a hollow pipe or a piece of round stock. The taper provides the seal.

piston 1. A cylindrical member that moves back and forth within a steel cylinder. 2. In a reciprocating engine, a cylindrical member that moves back and forth in the cylinder. Alternately compresses the fuel-air mixture and is pushed by the expanding gases to transfer mechanical power to the crankshaft of the engine.

piston displacement The total volume swept by the piston of an engine in one stroke (one half revolution) of the crankshaft. The total displacement of an engine would be equal to piston displacement multiplied by the number of pistons.

piston engine A reciprocating engine.

piston fuel pump Sometimes used as a main fuel pump in place of the more typical spur gear pump. This pump is capable of delivering fuel at higher pressures than other types and can also vary its output per revolution. A variable displacement-type pump.

piston insulator Composition insulators between the hydraulic actuating pistons and the pressure plate. Used to

prevent heat transferring from the pressure plate into the piston where it would likely damage the seals and the fluid.

piston pin The hardened steel pin that attaches the small end of a connecting rod into a piston.

piston pin boss The enlarged area on the interior of a piston that provides additional bearing area for the wrist pin.

piston pump A pump in a fluid power system used to move fluid and apply pressure to the system.

piston ring grooves The grooves in the circumference of a piston into which the piston rings fit.

piston rings Rings made of a special gray cast iron that fit into grooves in the periphery of a piston. Piston rings form a seal between the piston and the cylinder wall.

piston skirt The lower portion of a piston.

piston-type pump A hydraulic fluid pressure pump in which fluid is moved by pistons that move up and down in the cylinders of the pump.

pitch 1. The rotation of an airplane about its lateral axis. 2. The distance between the centers of adjacent rivets in the same row. 3. On threaded fasteners, the distance measured between corresponding points on two adjacent threads.

pitch angle In rotorcraft, the angle between the chord line of the rotor blade and the reference plane of the main rotor hub or the rotor plane of rotation.

pitch attitude The angle of the longitudinal axis relative to the horizon. Pitch attitude serves as a visual reference for the pilot to maintain or change airspeed.

pitch axis The lateral axis of an aircraft or the axis about which an aircraft pitches in a nose-up or nose-down attitude.

pitch, bolt threads The distance from any point on the thread of a screw to the corresponding point on an adjacent thread.

pitch of a propeller Zero-thrust pitch. The distance a propeller would have to advance in one revolution to give no thrust. Also referred to as experimental mean pitch.

pitch of screw thread The distance from the center of one thread to the center of the next thread.

pitch ratio of propeller The ratio of the pitch to the diameter.

pitch setting The propeller blade setting as determined by the blade angle measured in a manner, and at a radius, specified by the instruction manual for the propeller.

pitot pressure Ram or impact pressure used in the measurement of airspeed.

pitot static system The pressure system for airspeed indicators, altimeters, and vertical speed indicators. It consists of the pitot tube and a static port, along with all of the necessary tubing and moisture traps.

pitot tube An open-ended tube that faces directly into the relative airstream of an aircraft and picks up the ram, or pitot, pressure to be used in an airspeed indicator.

pitot-static tube A combination tube with the pick-up for the pitot pressure as well as openings that pick up undisturbed, or static, air pressure.

pitting The formation of small pockets on the surface of a metal.

pitting corrosion A metal corrosion in which small, localized pits filled with the corrosive salts form on the surface of the metal.

pivot trunnion A bearing surface on the top of the landing gear on which the gear rides when folding into the aircraft.

placard Small statement or pictorial sign permanently fixed in the cockpit and visible to the pilot. Placards are used for operating limitations (e.g., weight or speeds) or to indicate the position of an operating lever (e.g., landing gear retracted or down and locked).

plain bearing A simple bearing used to support an aircraft engine crankshaft or camshaft and only designed to take loads that are perpendicular to its face.

plain flap A wing flap in which a portion of the trailing edge of the wing folds down to increase the camber of the wing without increasing the wing area.

plain nut A simple hex nut that has no provisions for locking.

plain overlap seam A seam used for machine sewing of aircraft fabric in which the edge of one piece of fabric laps over the edge of the other and one or more rows of stitches hold the pieces together.

plain rib A rib used to give an airfoil its shape. Also referred to as a former rib.

plain washer A flat washer used to provide a smooth bearing surface for a nut or to shim between a surface and a nut.

plain weave A weaving pattern in which the warp and fill fibers alternate; that is, the repeat pattern is warp/fill/ warp/fill.

plan position indicator (PPI) scope A radar indicator scope displaying range and azimuth of targets in polar coordinates.

plan view The view from the top of an object.

plane of rotation The plane in which a propeller or a helicopter rotor rotates. It is perpendicular to the crankshaft or the rotor shaft.

plane of symmetry A vertical plane that passes through the longitudinal axis of an aircraft and divides the aircraft into two symmetrical sides.

planetary gears A reduction gearing arrangement in which the propeller shaft is attached to an adapter holding several small planetary gears. These gears run between a sun gear and a ring gear, either of which can be driven by the crankshaft, while the other is fixed into the nose section. Planetary gears reduce the propeller speed without reversing the direction of rotation.

planform The outline of a wing as viewed from above. The shape seen when looking at a top view of a blueprint or plan.

plans display A display available in URET CCLD (User Request Evaluation Tool Core Capability Limited Deployment ) that provides detailed flight plan and predicted conflict information in textual format for requested Current Plans and all Trial Plans.

Plante cell A secondary cell in which the pole pieces are formed of sheets of lead and lead dioxide. The electrolyte is a dilute solution of sulfuric acid.

plaque The base for plates of nickel-cadmium (Nicad) batteries. Plaque is covered by nickel, formed under heat and pressure onto a fine mesh nickel screen.

plasma A gas that is sufficiently ionized so as to affect its electrical properties and behavior. Plasmas are used in low temperature forms for the construction of integrated circuits and for providing light in fluorescent lights. In high temperature applications, they are used for cutting and welding metals and for propulsion for interplanetary probes.

plasma arc welding A very localized, high temperature form of welding that minimizes distortion of the metal being welded. See also plasma.

plasma coating The process of applying a thin coating of highly wear-resistant material on the surface of turbine engine parts. The process is accomplished by spraying material under high pressure and high heat onto the surface of the blades.

plasma engine An engine used in outer space that uses plasma technology for propulsion.

plasma generator A device that uses electricity, magnetism, and low pressures to generate ionized plasma gases. Also, a device that uses plasma gases to generate electricity.

plasma torch A device that utilizes hot, high velocity, ionized gases in the cutting and welding of metals.

plastic Any of the thermoplastic or thermosetting polymers used in modem aircraft construction.

plastic range The stress range of a material in which, though the material does not fail when subjected to force, the material does not completely return to its original shape but is deformed.

Plastic Wood A registered trade name for a filler consisting of wood fibers and a resin that sets as plasticizing solvents evaporate.

plasticizer A chemical used in a lacquer finish to give film its flexibility and resilience.

plate 1. The electrode in a vacuum tube that serves as the anode receiving the electrons from the cathode. 2. The active element in a storage battery. 3. Metal of a thickness greater than 1/4 . Metal thinner than is referred to as sheet metal.

plate current In a vacuum tube, the current that flows between the plate and the cathode.

plate glass A rolled sheet of glass that is ground and polished to provide an undistorted view.

plate power supply A high-voltage supply of positive direct current for use in vacuum tubes.

plate resistance In an electron tube, the ratio of a change in plate voltage to a change in plate current given a constant grid voltage.

plate saturation The condition in an electron tube when the plate will no longer attract electrons as fast as they are emitted by the cathode.

plating A process in which one metal is used to cover another using a process of electrical deposition. Specifically, chromium and cadmium are useful metals for covering steel.

platinum A hard, gray metallic element with a symbol of Pt and an atomic number of 78. Platinum has an extremely high melting point and is used for the electrodes of fine-wire spark plugs.

platinum spark plug A fine-wire electrode spark plug that can operate at very high temperatures.

play The relative movement between parts. Play is the amount of movement that occurs in a cockpit flight control before the associated flight surface to move.

P-LEAD

P-lead The primary lead of an aircraft magneto. Connected to the ignition switch.

plenum An enlargement of a duct or an enclosing space in an aircraft engine induction system or air conditioning system. Used to smooth out the pulsations in the flow of the air.

plenum chamber An enclosed volume of air in which the air is held at a slightly higher pressure than that of the surrounding air.

Plexiglas A transparent acrylic plastic material used for aircraft windshields and side windows.

pliers Small, pincher-like hand tools used for holding small objects or for bending and cutting wire.

plies Sheets of material that are laminated together.

plumb A weight attached to a line or string and used to indicate vertical direction. Anything that lines up with the plumb line is said to be plumb or in plumb.

plumb bob A weight attached to a line or string and used to establish a location directly below the point to which the line is attached.

plumb line The straight line of a string to which a plumb bob is attached and hung. Anything that lines up with the plumb line is said to be plumb or in plumb.

plumbing Tubing and fittings or connectors used for transmitting fluid within a structure or piece of equipment.

plumbing connection Threaded connections that join sections of tubing, or which are used to connect the tubing to a component.

plunger A part of a machine that works with a relatively rapid downward motion.

plutonium A radioactive metallic element with the symbol Pu and an atomic number of 94.

ply In composites, one layer of reinforcement in a laminate.

ply rating A load rating for aircraft tires that relates to the strength of cotton plies. For example, a 20-ply rating nylon tire has the same load rating as a tire with 20 cotton plies.

plywood Layers of wood glued together so that the grain in each layer is placed 45 or 90 to the others.

PN Junction In semiconductor devices, a PN junction is fabricated from a single slice of semiconductor with one side doped as P-type and the other side doped as N-type. In operation, the migration of electrons to the P side and the holes to the N side creates a depletion area that resists further migration of ions. The flow of current is then controlled by the types of voltage applied to the ends of the device.

pneudraulic A combination of air and hydraulic pressure.

pneumatic altimeter An altimeter that measures height above a given pressure level. Its calibration is based on a specified lapse rate or change in pressure with height.

pneumatic drill motor An air motor equipped with a chuck to hold twist drills.

pneumatic fire detection system A system that uses a gas-filled continuous tube. The gas expands when heated and acts on a diaphragm to close an electrical circuit and show a warning light in the cockpit.

pneumatic starter Starting motor operated by air pressure.

pneumatic system The power system in an aircraft used for operating landing gear, brakes, wing flaps, etc. with compressed air as the operating fluid.

pneumatic-mechanical fuel control A fuel control that utilizes pneumatic and mechanical forces to operate its fuel scheduling mechanisms.

pneumatics The system of fluid power that transmits force by the use of a compressible fluid.

PNP transistor The three-element semiconductor device made up of a sandwich of N-type silicon or germanium between two pieces of P-type material.

pod An enclosure housing a complete engine assembly.

pogonip A dense winter fog containing frozen particles. Forms in deep mountain valleys.

point out An action taken by a controller to transfer the radar identification of an aircraft to another controller if the aircraft will or can enter the airspace or protected airspace of another controller and radio communications will not be transferred. Also referred to as radar point out.

pointer A thin strip of movable metal moved over a calibrated scale by an analog instrument mechanism. Also referred to as hands or needles.

point-to-point wiring An antiquated method of building electronic units. Electronic components were mounted directly on the chassis and interconnected by means of wires that were integral parts of the components leads or by means of insulated hook up wire.

polar airmass An airmass with characteristics developed over high latitudes, especially within the sub polar highs. Continental polar air (cP) has cold surface temperatures, low moisture content, and, especially in its source regions, has great stability in the lower layers. It is shallow in comparison with Arctic air. Maritime polar (mP) initially possesses similar properties to those of continental polar air, but in passing over warmer water it becomes unstable with a higher moisture content. See also tropical airmass.

polar easterlies Surface winds generated by polar highs north of 60 N latitude.

polar front The semi-permanent, semi-continuous front separating airmasses of tropical and polar origins.

polar front jet stream One of two jet streams that commonly occur in the westerlies. Associated with the polar front.

polar front model An idealized representation of events that follow the development of a frontal low. The surface component of the model describes the structure and behavior of fronts and airmasses in the lower atmosphere.

The upper air part of the model deals with the associated development of troughs, ridges, and jet streams.

polar track structure A system of organized routes between Iceland and Alaska that overlie Canadian MNPS Airspace.

polarity The property of an electrical device having two different types of electrical charges: positive (deficiency of electrons) or negative (excess of electrons).

polarization A degradation in chemical cell performance, particularly in the case of Leclanche cells, caused by gas formation and the resulting insulation of portions of the pole area.

polarized capacitor A capacitor that can only be hooked up to direct current of the proper polarity. Electrolytic capacitors are normally polarized, and are labeled for proper polarity connection.

polarized light Light that has all the light waves in the same plane.

polarized receptacle A receptacle that has its sockets arranged so that the plug can only be inserted one way. This is done either through the shape of the plug/socket in two prong receptacles or by the arrangement of three or more prongs.

pole The designation given to the ends of a magnet.

pole shoes The field assembly part of an electric generator or motor.

poles of a magnet The north and south poles of a magnet where magnetic lines of flux leave the south pole and reenter at the north pole.

polishing The process of producing a smooth surface by rubbing it with fine abrasive wheels, belts, or compounds.

polyacrylonitrile (PAN) The base material used in manufacturing some types of carbon fibers.

polyconic projection A map projection where the parallels of latitude are arcs of a circle centered on the north or south pole and the meridians are straight lines radiating from the poles as in the spokes of a wheel.

polyester fiber A synthetic fiber noted for its mechanical strength, chemical stability, and long life. It is used to make woven fabric for covering aircraft structures.

polyester resin A synthetic resin, usually reinforced with fiberglass cloth or mat, and used to form complex shapes for aircraft structures.

polyethylene A lightweight, thermoplastic resin material with good chemical resistance. Polyethylene resins are used for making containers for liquids and sheets of protective covering material.

polyethylene plastic material A lightweight, thermoplastic resin material that has very good chemical- and moisture-resistant characteristics. It is used for plastic sheeting and containers.

Poly-Fiber A fabric woven from polyester fibers.

polymer paint A fast drying, water-based paint that contains vinyl or acrylic resins. When the water in the paint evaporates, it leaves a waterproof film of the plastic resin.

polymerization The process of joining two or more chemicals with molecules of similar structure, forming a more complex molecule with different physical properties. In this chemical reaction, the material essentially jells.

polymid A translucent plastic material commonly referred to as nylon.

polyphase alternating current Three-phase AC electricity produced by more than one set of generator windings.

polyphase electric motor An induction motor that operates on two-phase or three-phase AC.

polystyrene A transparent plastic used to make cell cases for some nickel-cadmium batteries.

polyurethane enamel A two-component, chemically cured enamel finishing system noted for its hard, flexible, high-gloss finish.

polyvinyl chloride (PVC) 1. A thermoplastic resin used in the manufacture of transparent tubing for electrical insulation and fluid lines that are not subject to any pressure. 2. A popular, low-cost, wire insulating material.

pontoon A float attached to the landing gear of a land airplane to allow it to operate from water.

poor judgment chain A series of mistakes that can lead to an accident or incident. Two basic principles generally associated with the creation of a poor judgment chain are: (1) one bad decision often leads to another; and (2) as a string of bad decisions grows, it reduces the number of subsequent alternatives for continued safe flight. Aeronautical decision making is intended to break the poor judgment chain before it can cause an accident or incident.

pop-open nozzle The afterburner nozzle that pops full open at idle for the purpose of efficient engine operation at very low thrust.

poppet valve A circular-headed, T-shaped valve. Used to seal the combustion chamber of a reciprocating engine, and at the proper time, either admit the fuel-air mixture into the cylinder or conduct the burned exhaust gases out of the cylinder.

porcelain A hard, smooth surfaced ceramic material.

pores Small holes or openings on the surface of metals.

porosity The condition of a material having small pores or small cavities throughout the material.

porous chrome A plating of hard chromium on bearing surfaces. The surface of the plating consists of tiny cracks in which lubricant can adhere to reduce sliding friction.

porous chrome plating An electrolytically deposited coating of chromium on the walls of aircraft engine cylinders. The surface contains thousands of tiny cracks that hold oil to provide for cylinder wall lubrication.

porous salt The residue normally left on the surface of a metal that has been attacked by corrosion.

porpoising Hunting, or oscillating, around the lateral axis of the aircraft normally caused by an incorrectly functioning automatic pilot.

port side The left-hand side of an aircraft or ship as one faces the nose of the aircraft or bow.

position error The error in an airspeed indicator caused by the static source not being exposed to absolutely still air.

position lights Lights on an aircraft consisting of a red light on the left wing, a green light on the right wing, and a white light on the tail. FARs require that these lights be displayed in flight during the hours of darkness.

position report A report over a known location as transmitted by an aircraft to ATC.

position symbol A computer-generated indication shown on a radar display to indicate the mode of tracking

positive Symbol: +. A condition of electrical pressure caused by a deficiency of electrons.

positive acceleration An increase in the rate of change of velocity.

positive angle of attack A flight condition where the angle of attack formed between the relative wind and the chord line of the airfoil is formed with the relative wind being the bottom leg in relation to the chord line and the so-called top surface of the aircraft.

positive buoyancy The tendency of an object, when placed in a fluid, to ascend or float because it is lighter than the fluid it displaces.

positive control Control of all air traffic, within designated airspace, by air traffic control.

positive control area An obsolete term that designated what is now referred to as Class A Airspace.

positive course guidance (PCG) A continuous display of navigational data that enables an aircraft to be flown along a specific course line, e.g., radar vector, RNAV, ground-based NAVAID.

positive electrical charge An electrical condition caused by a deficiency of electrons.

positive feedback In electronics, a signal fed from the output section back into the amplifier to reinforce the input signal.

positive ion An atom that has fewer electrons than protons.

positive logic The logic used in binary computers. The more positive signal is considered to be equal to a one and the less positive or more negative signal is considered to be equal to a zero.

positive static stability The condition of stability of an aircraft that causes it, when disturbed from a condition of straight and level flight, to tend to return to straight and level flight.

positive temperature coefficient A ratio that shows an increase in length, resistance, capacitance, etc. with an increase in temperature.

positive terminal The terminal of a battery or power source where electrons enter the source after they have passed through the external source.

positive transfer of learning Since students interpret new things in terms of what they already know, some degree of transfer is involved in all learning. During a learning experience, knowledge or skills they have gained in the past can aid students.

positive vorticity In weather, the vertical component of vorticity (i.e., a measure of how rapidly the air is spinning) leading to cyclonic flow. It is associated with upward air motions.

positive-displacement pump A fluid pump that moves a specific amount of fluid each time it rotates. Examples of positive-displacement pumps include gear pumps, gerotor pumps, and vane pumps.

positron The positive counterpart of an electron, which has the same mass and spin characteristics as an electron, but with a positive electrical charge.

post exit thrust reverser A thrust reverser used to reverse the hot exhaust stream of a gas turbine engine to help slow the airplane during landings.

postcure During the curing cycle of a manufactured composite component, the postcure is an additional elevated temperature soak to improve the mechanical properties.

pot life The usable life of a resin. The time before it begins to thicken after the catalyst and accelerator have been added.

potassium A metallic element with a symbol of K and an atomic number of 19.

potential The electrical pressure or voltage caused by dissimilar metals in an acid solution or an electrolyte.

potential barrier The difference in forward bias potential between the N side and the P side of a semiconductor. This is the amount of forward voltage necessary to begin current flow through a device. The nominal amount of the potential barrier is 0.3 volts for a germanium device and 0.7 volts for a silicon device. OK, but fails to mention the effect of temperature.

potential difference The difference in voltage that exists between two terminals or two points of differing potential.

potential drop A drop in voltage in an electrical circuit caused by the resistance of current flow through a resistance.

potential energy The energy possessed by an object because of its position, configuration, or chemical arrangement of its constituents.

potential instability A layer of air that is not only potentially unstable, it is conditionally unstable, and has a high moisture content. Potential instability is one of the two basic requirements for the formation of a thunderstorm; the other is initial lift.

potentiometer 1. A variable resistor having both ends and its wiper in the circuit. Used as a voltage divider. 2. An instrument used for measuring differences in electrical potential by balancing the unknown voltage against a known variable voltage.

potentiometer ohmmeter An ohmmeter circuit in which resistance is measured by placing a known voltage across a standard resistor; then the circuit is opened and the unknown resistor is placed in series. The voltage drop across the standard resistor is read and displaced on the meter as ohms.

pot-life In composites, the length of time that the resin, mixed with catalyst, will be in a workable state.

potted circuit connector An electrical circuit connector protected by encapsulating it with an insulating potting compound.

potting compound 1. A resin having filler capability, used to fill cells when making minor repairs to damaged honeycomb panels. 2. A non-hardening, rubber-like material used to moisture proof and protect the wires in certain electrical plugs.

pound A measure of mass equal to approximately 0.454 kg.

pour point 1. The lowest temperature at which a fluid will pour without disturbance. 2. The lowest temperature at which oil will gravity flow.

powder metallurgy A development that makes use of powdered metals rather than ingots. A process used to produce superalloys for high heat, high strength turbine components and for bearing material (sintered bearings).

powdered-iron core A molded, magnetic powdered iron mixed with a binder. Used in magnetic applications when high permeability and low eddy current losses are desired.

power amplifier An electronic device designed to create an increase in power (voltage times amperage) as opposed to an amplifier designed to create an increase in voltage.

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 to the force the pilot puts on the brake pedals.

power control system A control system in which the normal movement of the controls is assisted 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 (P) 1. The time-rate of doing work. Force times distance, divided by time. Power can be expressed in terms of foot-pounds of work per minute, or in horsepower (HP). One HP is 33,000 ft.-lbs. of work per minute. 2. The basic unit of electrical power is the watt, and 746 watts of electrical power is equal to one mechanical horsepower. In electrical problems, power is the product of voltage (E) times current (I) (P = E X I). Power in watts delivered to a circuit varies directly with

the square of the applied voltage and inversely with the circuit resistance.

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 compressor. Also referred to as free power turbine.

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.

powered-lift A heavier-than-air aircraft capable of vertical takeoff, vertical landing, and low speed flight that depends principally on engine-driven lift devices or engine thrust for lift during these flight regimes and on non-rotating airfoil(s) for lift during horizontal flight.

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 the 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.

precession One of the characteristics of a gyroscope that causes an applied force to be felt, not at the point of application, but 90 from that point in the direction of rotation.

precious metal Highly valued metal because of scarcity. Examples of precious metals are gold, silver, and platinum.

precipitable water The amount of liquid precipitation that would result if all water vapor were condensed.

precipitate To condense out of, or to separate from, a mixture.

precipitation Any or all forms of water particles (rain, sleet, hail, or snow), that fall from the atmosphere and reach the surface.

precipitation attenuation In radar meteorology, any process that reduces intensity of radar signals from precipitation.

precipitation fog Fog that develops when rain saturates the air near the ground.

precipitation hardening Hardening caused by the precipitation of a constituent from a supersaturated solid solution. A process of reheating an alloy and allowing it to cool slowly. Allows crystalline structure to harden uniformly.

precipitation heat treatment A step in the heat-treating process of aluminum in which the metal, after having been heated to its critical temperature and quenched, is raised to an elevated temperature and held for a period of time. This process artificially ages the metal and increases its strength.

precipitation static The static heard on communication gear when electricity is discharged from radio antennas or other objects on the aircraft as it flies through clouds containing ice particles.

P
recipitation-induced downdraft

precipitation-induced downdraft Downdrafts present inside of a thunderstorm that are induced by rainfall and are much stronger than downdrafts that exist outside of the thunderstorm.

precision approach (PA) An instrument approach based on a navigation system that provides course and glidepath deviation information meeting the precision standards of ICAO Annex 10. PAR, ILS, and MLS are precision approaches.

precision approach procedure A standard instrument approach procedure in which an electronic glide slope/ glide path is provided; e.g., ILS/MLS and PAR..

precision approach procedure A standard instrument approach procedure in which an electronic glideslope/ glidepath is provided; e.g., ILS, MLS, PAR.

precision approach radar (PAR) A radar system that uses two separate antenna. One is used to determine the aircraft s horizontal position relative to the extended centerline of the runway, and the other to determine the aircraft s vertical position relative to the glideslope leading to the runway. A ground controller directs the pilot of the aircraft horizontally and vertically to maintain position on centerline and on glideslope.

precision measuring instruments Instruments capable of making exact measurements.

precision runway monitor (PRM) Provides air traffic controllers with high precision secondary surveillance data for aircraft on final approach to parallel runways that have extended centerlines separated by less than 4,300 feet. High resolution color monitoring displays (FMA) are required to present surveillance track data to controllers along with detailed maps depicting approaches and no transgression zone.

precision switch A snap-action switch that actuates at the point when a mechanism reaches a very definite position. These switches typically have a plunger that requires an extremely small movement to trip and close the contacts. When the plunger is released, a spring snaps the contacts open.

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PDC

predeparture clearance (PDC) An automated Clearance Delivery system relaying ATC departure clearances from the FAA to the user network computer for subsequent delivery to the cockpit via ACARS (Airline/Aviation VHF data link) where aircraft are appropriately equipped, or to gate printers for pilot pickup.

predrilling The process of drilling a hole that is slightly smaller than required to enable reaming the hole to the proper size later.

pre-exit thrust reverser A thrust reverser system installed forward of the exhaust nozzle.

preferential routes Preferential routes (PDRs, PARs, and PDARs) are adapted in ARTCC computers to accomplish inter/intra-facility controller coordination and to assure that flight data is posted at the proper control positions. Locations having a need for these specific inbound and outbound routes normally publish such routes in local facility bulletins, and their use by pilots minimizes flight plan route amendments. When the workload or traffic situation permits, controllers normally provide radar vectors or assign requested routes to minimize circuitous routing. Preferential routes are usually confined to one ARTCC s area and are referred to by the following names or acronyms:

a. Preferential Departure Route (PDR) A specific departure route from an airport or terminal area to an enroute point where there is no further need for flow control. It can be included in an Instrument Departure Procedure (DP) or a Preferred IFR Route.

b. Preferential Arrival Route (PAR) A specific arrival route from an appropriate enroute point to an airport or terminal area. It can be included in a Standard Terminal Arrival (STAR) or a Preferred IFR Route. The abbreviation PAR is used primarily within the ARTCC and should not be confused with the abbreviation for Precision Approach Radar.

c. Preferential Departure and Arrival Route (PDAR) A route between two terminals that are within or immediately adjacent to one ARTCC s area. PDARs are not synonymous with Preferred IFR Routes but can be listed as such as they do accomplish essentially the same purpose.

preferred IFR routes Routes established between busier airports to increase system efficiency and capacity. They normally extend through one or more ARTCC areas and are designed to achieve balanced traffic flows among high density terminals. IFR clearances are issued on the basis of these routes except when severe weather avoidance procedures or other factors dictate otherwise. Preferred IFR Routes are listed in the Enroute Section. If a flight is planned to or from an area having such routes, but the departure or arrival point is not listed in the Enroute Section, pilots can use that part of a Preferred IFR Route that is appropriate for the departure or arrival point that is listed. Preferred IFR Routes are correlated with DPs and STARs and can be defined by airways, jet routes, direct routes between NAVAIDs, Waypoints, NAVAID radials/ DME, or any combinations thereof.

preflight inspection An aircraft inspection done prior to takeoff to determine that all systems are functioning properly for the intended flight.

pre-flight pilot briefing A service provided by the FSS to assist pilots in flight planning. Briefing items can include weather information, NOTAMs, military activities, flow control information, and other items as requested. Also referred to as a pilot briefing.

preform In composites, a preshaped fibrous reinforcement of mat or cloth formed to the desired shape on a mandrel or mock-up before being placed in a mold press.

preformed control cable Steel aircraft control cable whose individual strands were formed into a spiral before the cable was woven. This relieves the bending stresses within the cable and prevents the strands from spreading out when the cable is cut.

preignition Ignition occurring in the cylinder before the time of normal ignition. Preignition is often caused by a local hot spot in the combustion chamber igniting the fuel-air mixture.

pre-installation checks Checks made on a unit before installation.

pre-oiling A procedure that ensures oil has reached all critical lubrication points before an engine is started. Methods of pre-oiling include accumulators that maintain oil pressure in the system when the engine is not operating and operating the oil pump by itself before starting.

preparation The first step of the teaching process, consisting of determining the scope of the lesson, the objectives, and the goals to be attained. This portion also includes making certain all necessary supplies are on hand. In using the telling and doing technique of flight instruction, this step is accomplished prior to the flight lesson.

pre-preg In composites, reinforcing material that is pre-impregnated with resin/catalyst mixture. The resin system is in the B-stage and requires refrigerated storage. When heated, the resins begin to glow and will complete the cure when the temperature is elevated to its cure temperature for the proper amount of time.

prerotation In a gyroplane, it is the spinning of the rotor to a sufficient r.p.m. prior to flight.

presentation The second step of the teaching process, consisting of the delivery of the knowledge and skills that make up the lesson. The delivery would be by either the lecture method or demonstration-performance method. In the telling and doing method of flight instruction, this is where the instructor both talks about and performs the procedure.

press brake A sheet metal bending tool in which the sheet is placed on the bed with the sight line directly under the edge of the clamping bar with the correct bend radius die. The clamping bar is brought down to hold the sheet firmly in place and a bending leaf is raised until it bends the metal to the proper angle.

press fit A tight interference fit between machine parts. Requires one part to be pressed into the other.

press-to-test light A light that is tested by pressing the light fixture to complete the circuit to ground. If the light illuminates, the bulb is good.

pressure Force per unit area.

pressure altimeter A barometric instrument that indicates altitude. When set to standard sea level pressure of 29.92 inches of mercury, it indicates pressure altitude. When set to the local altimeter setting, it indicates indicated altitude from which true altitude can be calculated.

pressure altitude The height above the standard pressure level of 29.92 in. Hg. It is obtained by setting 29.92 in the barometric pressure window and reading the altimeter.

pressure capsule The portion of a structure subjected to pressurization. Usually consists of the cabin and cockpit.

pressure carburetor A fuel metering system that senses the relationship between impact air pressure and venturi pressure to provide a metering force for the fuel.

pressure casting A method of casting metal parts by forcing molten metal into permanent molds.

pressure controller That portion of a turbocharger control system that maintains the desired manifold pressure.

pressure demand oxygen system A demand oxygen system that supplies 100% oxygen at sufficient pressure above the altitude where normal breathing is adequate. Also referred to as a pressure breathing system.

pressure fed gun A paint spray gun in which the material is fed to the gun by air pressure on the pot or cup holding the material.

pressure gauge snubber A unit installed in the pressure gauge line that stabilizes pressures and allows the needle of the pressure gauge to give a steady reading.

pressure gradient The rate of change of pressure per unit distance at a fixed time.

pressure gradient force The force that arises because of the pressure of a pressure gradient.

pressure jump In weather, a sudden change in pressure reading.

pressure line Tubing that carries hydraulic fluid under pressure from the pump to the selector valve or the control valve.

pressure plate A heavy, stationary disc in a multiple disc brake. It is provided with a wear surface on one side only, and the pistons press against its backside to force the disk stack over against the back plate.

pressure port The opening in a device through which pressure is introduced.

pressure pot A container holding the material to be sprayed. An agitator keeps the material in motion, and a regulator maintains the proper air pressure on the material to feed it to the gun.

pressure ratio One pressure divided by another, used to describe certain engine functions. See also compressor pressure ratio; engine pressure ratio.

pressure ratio controller In turbocharged engines, controls the maximum turbocharger compressor discharge pressure (34 + or - .5 in. Hg to critical altitude of 18,000 ft.).

pressure reducing valve A device that reduces the pressure of a liquid or gas from a high value to a fixed lower value.

pressure regulator In a hydraulic system, a device that maintains a constant output pressure from a constant displacement pump by bypassing a portion of the fluid back to the inlet side of the pump.

pressure relief valve In a hydraulic system, a pressure control valve that bypasses fluid back to the return manifold or reservoir in the event the pressure rises above a predetermined level.

pressure seal A seal installed in a pressure bulkhead to permit a cable to pass through it.

pressure sensing switch An electrical switch that will open or close when a predetermined pressure is reached in a system.

pressure, static The pressure measured in a duct containing air, a gas or a liquid in which no velocity (ram) pressure is allowed to enter the measuring device. Symbol Ps.