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photonics
as distinct from electrons, with properties based on an
arrangement of atoms on an artificial structure.
photonics Using light to process RF signals.
photon rocket Theoretically achievable rocket whose
working fluid is light, ie stream of photons; small thrust
but in deep space very high I sp , and vehicle velocity could
be significant fraction of that of light.
photopic vision Using retinal cones, hence colours distinguishable.
photo reconnaissance Military mission to bring back
images of scenes in enemy territory, such as buildings and
structures, troop movements, ships and results of previous
attacks. Can be high vertical, low oblique, stereo, overlapping
strip, etc.
photosensitivity Degree to which substance changes
chemical or electrical state when light falls on it.
photosensor Device operating by photoconductivity, eg
light valve.
photosmoke method One of two techniques for
measuring smokiness of jet by direct determination of
optical density (other is Hartridge); gives output in PSU.
photosphere Intensely hot, bright outer layer of Sun’s
atmosphere.
phototheodolite Instrument comprising camera whose
azimuth and elevation are precisely recorded (usually on
its own film).
phototransistor Solid-state device, originally Ge wafer,
generating holes by light absorption and multiplying this
photocurrent by transistor action at collector.
phototube Electron tube (vacuum tube) containing
photoemissive cathode and collecting anode (usually plus
other sub-devices).
photovoltaic cell Transducer which, like photoelectric
cell, converts EM radiation in visible or near-visible wavelengths
into electricity; unlike photocell its purpose is to
generate usable current instead of merely giving signal or
serving other purpose calling for very low power; example
is solar cell.
phraseology Accepted forms of speech, codes phonetic
alphabet, etc, used to facilitate telecommunications,
usually by voice.
PHS Precision hover sensor.
PHT 1 Private pilot, helicopter, recreational, transition.
2 High-temperature platform.
phugoid One of the five classical modes of aeroplane
motion, a long-period oscillation of pitch axis, perpetually
hunting about level attitude and trimmed speed, a
switchback trajectory at almost unvarying AOA; noun
and also adj, eg * oscillation.
phut-phut Put-put.
PHY Physical interface (device).
P hvd Fluid system pressure, esp. hydraulic test pressure
of rocket motor case.
physics package Warhead of an air-delivered NW [freefall
or cruise missile] (RAF usage).
PI 1 Point of interception (navigation plot).
2 Photographic interpreter (or interpretation).
3 Process (or program) instruction.
4 Practice interception.
5 Program introduction (D adds ‘document’).
6 Production investment.
7 Production installation, of new equipment in Service
aircraft.
8 Product improvement.
9 Precipitation identification.
10 Parameter identifier.
11 Pipeline inspection.
12 Principal investigator.
13 Performamce Index [usual meaning in flight-control
systems].
14 Parallel interface [bus].
Pi Input power, esp. of jammer.
PIA 1 Pilots’ International Association [office,
Minneapolis, MN] (US).
2 Pilot-interpreted approach.
3 Proprietary Industries Association (US).
4 Performance integrity and availability.
5 Pittsburgh Institute of Aeronautics [PA15236] (US).
PIAC, Piac Peak instantaneous airborne count[s].
PIAG, Piag Propulsion Installation Advisory Group
(Int.).
Pianeg, Pianet Planning the implementation of an
improved AFS/AFTN network (ICAO).
piano hinge One continuous along edge of hinged item.
piano keys Black/white runway end markings (colloq.).
piano wire Finest steel wire normally produced;
0.8–0.95% C, very high uts, accurate dimensionally.
PIB Preflight information bulletin.
Pibal Pilot-balloon aloft (observation).
PIC 1 Pilot in command.
2 Prime integration contract.
3 Price-improvement curve.
4 Potential icing [category].
PCA, PICA Phenolic-impregnated carbon ablator.
Picao, PICAO Provisional ICAO (1945–47).
Picasso Predicted ionograms correlated against
segmented swept output (ionospheric analysis).
PICC Processor interface controller and communication.
piccolo actuator PFCU or other actuator whose output
is generated by row of parallel jacks fitting within thin
aerofoil.
piccolo tube Tube perforated by (usually linear) row of
holes from which hot deicing air is blown, usually to
impinge on inside surface of a leading edge.
pick-a-back 1 See composite aircraft.
2 Superimposed printed-circuit boards.
picket 1 AEW or AWACS aircraft.
2 Instrumented oceangoing ship on missile range.
picketing Securing aircraft against movement when
parked in open, normally by attachment to heavy masses
or spiral rods screwed into ground.
picketing anchor Spiral rod with eye at upper end.
pickle Tactical air code: moment of manual triggering of
system, esp. release of ordnance on surface target.
pickle button That commanding release of airdropped
stores.
pickled facility Warm long-term storage, esp. for NW.
pickling Soaking in dulute acid solutions to remove
oxides or other surface films or inter-crystalline carbides
and surface scale. Principal acids are HCl, H 2 SO 4 , HNO 3
and HFl.
pick-off Sensor of angular motion or position; many
types, eg electric potentiometer, angular digitizer, photocell,
magnetic coil moving-iron reluctance bridge, or
fluidic valve or gate.
pickoff excitation Normally a frequency.
pickoff excitation
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