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pushrod
directional output interleaved by weak or slow return
stroke.
pushrod Rod transmitting cam motion of valve gear to
rocker or other drive to poppet valve(s).
PUT 1 Pop-up test of ICBM, SLBM, ABM or other
launch system of externally energized cold-launch type.
2 Pilot under training, or tuition, also Pu/t.
put-put Small underpowered aeroplane [onomatopoeia].
PV 1 Pressure/volume or pressure × volume.
2 Private-venture aircraft.
3 Product verification (formerly MQT).
4 Prevailing visibility.
5 Prime vendor.
6 Positive vetting.
7 Post vacant.
8 Parameter value.
PVA 1 Polyvinyl acetate (or pva).
2 Plane view area, normally of precision forging.
PVASI Para, or pulsating, visual approach slope
indicator.
PVB Polyvinyl butyral (or pvb).
PVC 1 Polyvinyl chloride (or pvc).
2 Permanent virtual circuit.
PVD 1 Para-visual director.
2 Plan-view display; -E adds emulator.
3 Peripheral-vision display.
4 Air-data sensor, esp. pitot, pitch, yaw (USSR, R).
PVDF Polyvinylidene fluoride (or pvdf).
PVDU Portable VOR deviation unit.
PVF, pvf 1 Polyvinyl fluoride.
2 Polyvinyl film.
PVI 1 Pilot/vehicle interface.
2 Para-visual indicator.
PVL Prevail.
PVLS Peripheral vertical-launch system.
PVM Primary visual marker.
PVO Air defence of the homeland, made up of IA
(manned interceptors) and ZR (zenith rockets, ie SAMs)
(USSR, R).
PVOR Precision VOR.
PVO-SV Troops of air defence of ground forces
(USSR, R).
PVR Premature voluntary retirement.
PVRD Ramjet (USSR, R).
PVS 1 Pilot’s vision system, or visual subsystem.
2 Prime Vendor Support (USN).
PVS Pitch of tunnel vane set (distance between vanes).
PVT 1 Product verification test.
2 Private [operator].
3 Position/velocity/time.
4 Personal verifier terminal.
PVTOS Physical vapour transport of organic solids, for
space manufacturing.
PVU 1 Portable ventilator unit.
2 Precision velocity update.
PVV Proof vertical velocity (MLG demo case).
PW 1 Pulse width.
2 Plated wire (memory).
3 Potable water.
4 Pursuit, water-cooled (USA 1919–24).
PWA Public Works Administration (US from 1933).
PWB Pilot[’s] weather briefing.
PWBH Pilot’s Weight and Balance Handbook (US).
PWC Professional Women Controllers (US).
pyramidal absorber
PWD Present-weather detector (visibility, precipitation,
snow depth).
PWG Planning Working Group (Eurocontrol).
PWHQ Primary war headquarters.
PWI 1 Proximity, or pilot, warning indicator.
2 Preliminary warning instruction.
PWIN Prototype WWMCCS intercomputer network.
PWM Pulse-width modulation, or modulated: hence
PWMI = * inverter.
PWP 1 Pylon weight plug.
2 Plasticized white phosphorus.
PWQT Potable-water quantity transmitter.
PWR 1 Power.
2 Passive warning radar.
PWRS Prepositioned war reserve stocks.
PWS 1 Proximity warning system (generally helicopter
applications).
2 Performance work statement.
3 Potable water supply.
PWSC Preferred weapon-system concept.
PWSDE Effective power delivered at shaft of turboprop
= ehp.
PWT 1 Propulsion wind tunnel.
2 Plasma wind tunnel.
PWTD Predictive windshear and turbulence detection.
PWW Predictive windshear warning.
PX Post Exchange, became BX and today AAFEX,
which see.
PY 1 Program(me) year.
2 Spray.
P(Y) Precise encrypted (GPS).
PYBBN Pitch yaw balanced-beam nozzle.
pylon 1 Rigid pillar-like structure projecting upwards to
carry load (eg engine) or protect occupants in overturn
(crash *).
2 Streamline-section structure transmitting stress from
external load to airframe, eg engine pod, ordnance, drop
tank etc. Can extend above or below wing or horizontally
or at other angle from fuselage. For engine pod often
extended to *strut.
3 Object on surface used as landmark for race turning
point.
4 Object on surface used as reference for pilots
performing flight manoeuvres.
5 Aircraft [usually private or club] tipped on nose, tail
in air (colloq.).
pylon select I/O device linking crew to WCS (weapon
control system) or Navwass, enabling specific pylons, ie
particular portions of load, to be selected for attack on
particular target.
pylon spar Principal structural member of engine pylon
normally (in case of wing engine) linking engine mounts
direct to wing box.
pylon strut Pylon (2) linking engine pod to wing or rear
fuselage.
Pyralin Cellulose-base transparent plastic formerly
used for windows.
pyramidal absorber Family of absorbers of EM radiation
(ie RAM 2) and noise, characterized by entire surface
of structure being covered by long pointed pyramids with
apices pointing towards source of radiation. Similar
geometry is found in airframe underlying structure of lowobservables
aircraft.
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