Glossary of aviation
Terms
and abreviations.
QUADRAPLANE, QUADRUPLANE - An aircraft having four or more
wingforms.
RADAR APPROACH CONTROL FACILITY (RAPCON) - A terminal ATC
facility that uses radar and non-radar capabilities to provide
approach control services to aircraft arriving, departing,
or transiting airspace controlled by the facility. This facility
provides radar ATC services to aircraft operating in the vicinity
of one or more civil/military airports in a terminal area.
The facility may provide services of a ground-controlled approach
(GCA). A radar approach control facility may be operated by
FAA or a military service, or jointly. Specific facility nomenclatures
are used for administrative purposes only and are related
to the physical location of the facility and the operating
service generally:
Army Radar Approach Control (ARAC) (Army)
Radar Air Traffic Control Facility (RATCF) (Navy/FAA)
Radar Approach Control (RAPCON) (Air Force/FAA)
Terminal Radar Approach Control (TRACON) (FAA)
Tower/Airport Traffic Control Tower (ATCT) (FAA only
towers delegated approach control authority)
RADIO COMPASS SEE RADIO NAVIGATION
RAMJET - An aerodynamic duct in which fuel is burned to produce
a high-velocity propulsive jet. It needs to be accelerated
to high speed before it can become operative.
RING COWLING - A circular engine FAIRING.
ROGALLO WING - A flexible, delta-wing plan in which three
rigid members are shaped in the form of an arrowhead and joined
by a flexible fabric, which inflates upward under flight loads.
Originally specific to paragliders, but now found on some
powered aircraft.
ROLL - Of the three axes in flight, this specifies the action
around a central point. Compare PITCH and YAW.
ROTARY ENGINE - A powerplant that rotates on a stationary
propeller shaft. An American invention by Adams-Farwell Co
(1896), it was first used for buses and trucks in the US (1903),
then copied by French engineers for early aircraft engines
(1914).
ROTORCRAFT - A heavier-than-air aircraft that depends principally
for its support in flight on the lift generated by one or
more rotors. Includes helicopters and gyroplanes.
RUDDER - The movable part of a vertical airfoil which controls
the YAW of an aircraft; the fixed part being the FIN.
SAILPLANE - An unpowered, soaring aircraft capable of maintaining
level flight for long periods of time after release from tow
and of gaining altitude using wind currents, as opposed to
a GLIDER.
SCRAMJET - Acronym for supersonic combustion ramjet, in which
combustion occurs at supersonic air velocities through the
engine.
SCUD - A low, foglike cloud layer.
SEAPLANE - A water-based aircraft with a boat-hull fuselage,
often amphibious.The term is also used generically to define
a similar Flying Boat and a pontoon FLOATPLANE.
SECONDARY STALL - Any stall resulting from pulling back too
soon and too hard while recovering from any other stall. Usually
a HIGH-SPEED or ACCELERATED STALL.
SERVICE CEILING - The height above sea level at which an
aircraft with normal rated load is unable to climb faster
than 100' per minute under Standard Air conditions.
SESQUI-WING - A lesser-span additional wingform, generally
placed below the main planes of an aircraft, generally a biplane.
SHOULDER-WING - A mid-wing monoplane with its wing mounted
directly to the top of the fuselage without use of CABANE
STRUTs.
SIDESLIP - A movement of an aircraft in which a relative
flow of air moves along the lateral axis, resulting in a sideways
movement from a projected flight path, especially a downward
slip toward the inside of a banked turn.
SINK, SINKING SPEED - The speed at which an aircraft loses
altitude, especially in a glide in still air under given conditions
of equilibrium.
SKID - Too shallow a bank in a turn, causing an aircraft
to slide outward from its ideal turing path.
SLATS - Movable vanes or auxiliary airfoils, usually set
along the leading edge of a wing but able to be lifted away
at certain angles of attack.
SLIP - Too steep a bank in a turn, causing an aircraft to
slide inward from its ideal turing path.
SLIPSTREAM - The flow of air driven backward by a propeller
or downward by a rotor.
SLOT - A long, narrow, spanwise gap in a wing, usually near
the leading edge, to improve airflow at high angles of attack
for slower landing speeds.
SLOTTED FLAP - A flap that, when depressed, exposes a slot
and increases airflow between itself and the rear edge of
the wing.
SMOH - "Since Major Overhaul," an acronym seen
in reference to the operating hours, or time remaining, on
an engine.
SPECIAL USE AIRSPACE (SUA) - Airspace of defined dimensions
identified by an area on the surface of the earth wherein
activities must be confined because of their nature and/or
wherein limitations may be imposed upon aircraft operations
that are not a part of those activities:
Alert Area - Airspace which may contain a high volume of pilot
training activities or an unusual type of aerial activity,
neither of which is hazardous to aircraft. Alert Areas are
depicted on aeronautical charts for the information of non-participating
pilots. All activities within an Alert Area are conducted
in accordance with Federal Aviation Regulations, and pilots
of participating aircraft as well as pilots transiting the
area are equally responsible for collision avoidance.
Military Operations Area (MOA) - Airspace established outside
of Class A airspace area to separate or segregate certain
non-hazardous military activities from IFR traffic and to
identify for VFR traffic where these activities are conducted.
Prohibited Area - Airspace designated under part 73 within
which no person may operate an aircraft without the permission
of the using agency.
Restricted Area - Airspace designated under FAR Part 73, within
which the flight of aircraft, while not wholly prohibited,
is subject to restriction. Most restricted areas are designated
joint use and IFR/VFR operations in the area may be authorized
by the controlling ATC facility when it is not being utilized
by the using agency. Restricted areas are depicted on enroute
charts. Where joint use is authorized, the name of the ATC
controlling facility is also shown.
Warning Area - A warning area is airspace of defined dimensions
extending from 3 nautical miles outward from the coast of
the USA, that contains activity that may be hazardous to non-participating
aircraft. The purpose of such warning area is to warn non-participating
pilots of the potential danger. A warning area may be located
over domestic or international waters or both.
SPLIT FLAP - A FLAP built into the underside of a wing, as
opposed to a Full Flap wherein a whole portion of the trailing
edge is used.
SPOILER - A long, movable, narrow plate along the upper surface
of an airplane wing used to reduce lift and increase drag
by breaking or spoiling the smoothness of the airflow.
SPORT PILOT - Special FAA certification enabling "budget"
pilotry; see LIGHT SPORT AIRCRAFT and LSA feature.
SPONSON - A short, winglike protuberance on each side of
a seaplane to increase lateral stability.
SQUAWK - A four-digit number which is dialed into his transponder
by a pilot to identify his aircraft to air traffic controllers
STABILATOR - A movable horizontal tail that combines the
actions of a stabilizer and elevator, increasing longitudinal
stability while creating a pitching moment.
STABILIZER - The fixed part of a horizontal airfoil that
controls the pitch of an aircraft; the movable part being
the ELEVATOR.
STAGGER - The relative longitudinal position of the wings
on a biplane. Positive Stagger is when the upper wing's leading
edge is in advance of that of the lower wing [eg: Waco YKS],
and vice versa for Negative Stagger [eg: Beechcraft D17].
STALL - (1) Sudden loss of lift when the angle of attack
increases to a point where the flow of air breaks away from
a wing or airfoil, causing it to drop. (2) A maneuver initiated
by the steep raising of an aircraft's nose, resulting in a
loss of velocity and an abrupt drop.
STANDARD AIR (Standard Atmosphere) - An arbitrary atmosphere
established for calibration of aircraft instruments. Standard
Air Density is 29.92 inches of mercury and temperature of
59° F, equivalent to an atmospheric air pressure of 14.7#
per square inch.
STANDARD RATE TURN - A turn in which the heading of an aircraft
changes 3° per second, or 360° in two minutes.
STATIC WIRE - A clip-on wire used to ground an aircraft by
drawing off static electricity, a potential fire hazard, during
refueling.
SUA SEE SPECIAL USE AIRSPACE
SUPERSONIC - Speed of flight at or greater than Mach 1.0;
literally, faster than the speed of sound.
SWEEPBACK - A backward inclination of an airfoil from root
to tip in a way that causes the leading edge and often the
trailing edge to meet relative wind obliquely, as wingforms
that are swept back.
SWING-WING - A wing whose horizontal angle to the fuselage
centerline can be adjusted in flight to vary aircraft motion
at differing speeds.
TAILDRAGGER SEE CONVENTIONAL GEAR
TARMAC - (1) A bituminous material used in paving; a trade
name for Tar MacAdam. (2) An airport surface paved with this
substance, especially a runway or an APRON at a hangar.
TAS - True Air Speed. Because an air speed indicator indicates
true air speed only under standard sea-level conditions, true
air speed is usually calculated by adjusting an Indicated
Air speed according to temperature, density, and pressure.
Compare CALIBRATED AIR SPEED and INDICATED AIR SPEED.
TCA SEE CONTROLLED AIRSPACE
TERMINAL RADAR SERVICE AREA (TRSA) - Airspace surrounding
designated airports wherein ATC provides radar vectoring,
sequencing, and separation on a full-time basis for all IFR
and participating VFR aircraft. Service provided at a TRSA
is called Stage III Service. TRSAs are depicted on VFR aeronautical
charts. Pilot participation is urged but is not mandatory.
TETRAHEDRON - Ground-based, free-rotating, triangular-shaped
wind direction indicator, genrally placed near a runway.
THRUST - The driving force of a propeller in the line of
its shaft or the forward force produced in reaction to the
gases expelled rearward from a jet or rocket engine. Opposite
of DRAG.
TORQUE - A twisting, gyroscopic force acting in opposition
to an axis of rotation, such as with a turning propeller;
aka Torsion.
TOUCH-AND-GO - Landing practice wherein an aircraft does
not make a full stop after a landing, but proceeds immediately
to another take-off.
TRACTOR - A propeller mounted in front of its engine, pulling
an aircraft through the air, as opposed to a PUSHER configuration.
TRAILING EDGE - The rearmost edge of an AIRFOIL.
TRANSPONDER - An airborne transmitter that responds to ground-based
interrogation signals to provide air traffic controllers with
more accurate and reliable position information than would
be possible with "passive" radar; may also provide
air traffic control with an aircraft's altitude.
TRIKE - Nickname for a weight-shift-control aircraft, such
as a paraglider.
TRIM TAB - A small, auxiliary control surface in the trailing
edge of a wingform, adjustable mechanically or by hand, to
counteract ("trim") aerodynamic forces on the main
control surfaces.
TRUE AIRSPEED - The speed of an aircraft along its flight
path, in respect to the body of air (air mass) through which
the aircraft is moving. Also see CALIBRATED AIRSPEED, GROUND
SPEED, INDICATED AIRSPEED.
TRUE NORTH - The northern direction of the axis of the Earth;
aka "Map North." GEOGRAPHIC NORTH, as opposed to
MAGNETIC NORTH.
TURBOJET - An aircraft having a jet engine in which the energy
of the jet operates a turbine that in turn operates the air
compressor.
TURBOPROP - An aircraft having a jet engine in which the
energy of the jet operates a turbine that drives the propeller.
Paragliding Spain Center
