FAR Part 137 - Agricultural Aircraft OperationsQBR>
FAR Part 141 - Pilot School
FERRY FLIGHTA flight for the purpose of (1) returning an aircraft to base; (2) delivering an aircraft from one location to another; (3) moving an aircraft to and from a maintenance base. Ferry flights, under certain conditions, may be conducted under terms in a special flight permit.
FINThe fixed part of a vertical airfoil that controls the yaw of an aircraft; the movable part being the RUDDER. Sometime referred to as Vertical Stabilizer.
FIREWALLA fire-resistant bulkhead that isolates the engine from other parts of an airplane's structure.
FISHTAILINGA rudder-controlled side-to-side [yawing] motion to reduce air speed, generally prior to landing.
FIVE-BY-FIVE (5x5)In radio jargon, affirms that a radioed transmission was received clear and loud. Rated one to five, with the first figure for clearness and the second second for loudness.
FLAPA movable, usually hinged AIRFOIL set in the trailing edge of an aircraft wing, designed to increase LIFT or DRAG by changing the CAMBER of the wing or used to slow an aircraft during landing by increasing lift. Also see FOWLER FLAP, SLOTTED FLAP, and SPLIT FLAP.
FLAPERONA control surface combining the functions of a FLAP and an AILERON.
FLAREA maneuver performed moments before landing in which the nose of an aircraft is pitched up to minimize the touchdown rate of speed.
FLIGHT ENVELOPEAn aircraft's performance limits, specifically the curves of speed plotted against other variables to indicate the limits of speed, altitude, and acceleration that a particular aircraft can not safely exceed.
FLIGHT LEVEL (FL)A level of constant atmospheric pressure related to a reference datum of 29.92 inches of mercury. Each is stated in three digits that represent hundreds of feetflight level 250 represents a barometric altimeter indication of 25,000', flight level 255 an indication of 25,500'.
FLIGHT PLANSpecified information relating to the intended flight of an aircraft that is filed orally or in writing with an FSS or an ATC facility.
FLIGHT SERVICE STATION (FSS)Air traffic facilities which provide pilot briefing, enroute communications and VFR search and rescue services, assist lost aircraft and aircraft in emergency situations, relay ATC clearances, originate Notices to Airmen, broadcast aviation weather and NAS information, receive and process IFR flight plans, and monitor NAVAIDs. In addition, at selected locations, FSSs provide Enroute Flight Advisory Service (Flight Watch), take weather observations, issue airport advisories, and advise Customs and Immigration of transborder flights.
FLOATPLANEA water-based aircraft with one or more mounted pontoons, as differentiated from a hulled SEAPLANE or Flying Boat, but sometimes used generically.
FLYING WIRESInterplane bracing wires that help support wingloads when the plane is in flight. Direction of travel is upward and outward from the fuselage to the interplane struts. Also known as LIFT WIRES, the opposite of LANDING WIRES.
FOWLER FLAPTrademark name of a split-flap attached to a wing through a system of tracks and rollers to roll the flap backward and downward, increasing the wing area.
FRISE AILERONA type of aileron that has a beveled leading edge projecting beyond its inset hinges. When lowered, it forms an extension of the wing surface; when raised, its nose protrudes below the wing, increasing DRAG and reducing YAW. Named after its inventor, British engineer Leslie George Frise.
FSS SEE FLIGHT SERVICE STATION
FUSELAGEAn aircraft's main body structure housing the flight crew, passengers, and cargo and to which the wings, tail and, in most single-engined airplanes, engine are attached. French: fuselé, tapering.
g or G SEE LOAD FACTOR
GCAGround-Controlled Approach; part of ILS.
GENERAL AVIATIONThat portion of civil aviation which encompasses all facets of aviation except air carriers holding a certificate of public convenience and necessity from the Civil Aeronautics Board and large aircraft commercial operators.
GLASS COCKPITSaid of an aircraft's control cabin which has all-electronic, digital and computer-based, instrumentation.
GLIDERAn unpowered aircraft capable of maintaining altitude only briefly after release from tow, then gliding to earth. Compare SAILPLANE.
GLIDE SLOPE(1) The angle between horizontal and the glide path of an aircraft. (2) A tightly-focused radio beam transmitted from the approach end of a runway indicating the minimum approach angle that will clear all obstacles; one component of an instrument landing system (ILS).
GPSGlobal Positioning System; satellite-based navigation.
GREEN LIGHTApproval for landing. A carryover expression from days when aircraft for the most part had no radios, and communication from a control tower was by means of a light-gun that beamed various green, red, and yellow signals to pilots in the air and on the ground.
GROSS WEIGHTThe total weight of an aircraft when fully loaded; aka Takeoff Weight.
GROUND CONTROLTower control, by radioed instructions from air traffic control, of aircraft ground movements at an airport.
GROUND EFFECTIncreased lift generated by the interaction between a lift system and the ground when an aircraft is within a wingspan distance above the ground. It affects a low-winged aircraft more than a mid- or high-winged aircraft because its wings are closer to the ground; aka GROUND CUSHION.
GROUND SPEEDThe actual speed that an aircraft travels over the groundits "shadow speed"; it combines the aircraft's AIR SPEED and the wind speed relative to the aircraft's direction of flight.
GULL-WINGDescriptive of wing in frontal view bent as the wing of a seagull; a distinctive shallow, inverted "V" shapesee Stinson SR-7 or inverted gull-wing Vought F4U.
HANGARAn enclosed structure for housing aircraft. Originated with lake-based floating homes of the original German Zeppelins in which they were "hung" from cables, which explains the erroneous, oft-seen spelling of "hanger." French: shed, outbuilding, from Latin: angarium,shed.
HELICOPTERA wingless aircraft acquiring its lift from revolving blades driven by an engine about a near-vertical axis. A ROTORCRAFT acquiring its primary motion from engine-driven rotors that accelerate the air downward, providing a reactive lift force, or accelerate the air at an angle to the vertical, providing lift and thrust.
HIGH-SPEED STALLAny stall made to occur at more than 1g, such as pulling out of a dive or while turning.
HORSEPOWERThe motive energy required to raise 550# one foot in one second, friction disregarded.
HYPERSONICSpeed of flight at or greater than Mach 5.0, exceeding SUPERSONIC.
IFRInstrument Flight Rules, governing flight under instrument meteorological conditions.
ILSInstrument Landing System. A radar-based system allowing ILS-equipped aircraft to find a runway and land when clouds may be as low as 200 feet (or lower for special circumstances).
INDICATED AIRSPEED (IAS)A direct instrument reading obtained from an air speed indicator uncorrected for altitude, temperature, atmospheric density, or instrument error. Compare CALIBRATED AIRSPEED and TRUE AIRSPEED.
INSTRUMENT METEOROLOGICAL CONDITIONS (IMC)Meteorological conditions expressed in terms of visibility, distance from clouds, and ceiling less than minima specified for visual meteorological conditions (VMC).
IRON COMPASSRailroad tracks, as favored by pilots of yore as a dependable aid to surface navigation.
JOYSTICKA single floor- or roof-mounted control sticksideways movement produces ROLL, and forward/backward movement produces PITCH (rudder pedals produce YAW).
KNOTOne nautical mile, about 1.15 statute miles (6,080'); eg: 125kts = 143.9mph.
LAMINAR-FLOW AIRFOILA low-drag airfoil designed to maintain laminar flow over a high percentage of the chord about itself. Often relatively thin, especially along the leading edge, with most of its bulk near the center of the chord.
LIFTThe force exerted on the top of a moving airfoil as a low-pressure area that causes a wingform to rise.
LIFT-DRAG RATIOThe lift coefficient of a wing divided by the drag coefficient, as the primary measure of the efficiency of an aircraft; aka L/D Ratio.
LIFT WIRESInterplane bracing wires that help support wingloads when the plane is in flight. Direction of travel is upward from the bottom of the fuselage to the top of the interplane struts. Also known as FLYING WIRES, the opposite of LANDING WIRES.
LIGHT SPORT AIRCRAFTSpecial FAA certification class (LSA) for an aircraft other than a helicopter or powered-liftsingle-engine aircraft, airship, balloon, GLIDER, GYROCOPTER, ROTORCRAFT, weight-shift-control aircraft. While limiting the types of aircraft that could be flown by a Sport Pilot, it simplified requirements for a obtaining a pilot license and did not require a medical examination. SEE LSA feature.
LIQUID COMPASSA non-electronic, calibratable compass floating in a liquid as a panel instrument; aka Wet Compass.
LOAD FACTOR (g)The proportion between lift and weight commonly seen as g (sometimes capitalized)a unit of force equal to the force of gravity times one.
LOFTINGDesign or fabrication of a complex aircraft component, as with sheet metal, using actual-size patterns or plans, generally laid out on a floor. The term is borrowed from boat builders.
LONGERONA principal longitudinal member of a fuselage's framing, usually continuous across a number of supporting points.
LOOP ANTENNAA circular radio antenna, either in the open or in a streamlined, teardrop housing, remotely turned 360° to fine-tune a station in league with other radio-directive devices. See also RADIO COMPASS, RADIO DIRECTION FINDER.
LORANLong Range Navigation system, which utilizes timing differences between multiple low-frequency transmissions to provide accurate latitude/longitude position information to within 50'.
LTALighter-than-air craft, generally referring to powered blimps and dirigibles, but often also includes free balloons.
Mach or m.A number representing the ratio of the speed of an object to the speed of sound in the surrounding air or medium in which it is moving.
MAGNETIC COMPASSThe most common liquid-type compass, capable of calibration to compensate for magnetic influences within the aircraft.
MAGNETIC COURSECOMPASS COURSE ± deviation.
MAGNETIC NORTHThe magnetic North pole, located near 71° North latitude and 96° West longitude, that attracts a magnetic compass which is not influenced by local magnetic attraction, as opposed to GEOGRAPHIC NORTH.
MAGNETO, MAGAn accessory that produces and distributes a high-voltage electric current for ignition of a fuel charge in an internal combustion engine.
MAGNUS EFFECTThe effect on a spinning cylinder or sphere moving through a fluid, in which force acts perpendicular to the direction of motion and to the direction of spin. This is used to advantage in baseball, in which the trajectory of a pitched ball is a distinct curve. Applied to aeronautics in experimental wingforms, the Magnus Theory states that if air is directed against a smooth, revolving cylinder, whose circumferential speed is greater than that of the air current, a force is directed against one side of the cylinderair compressed on one side and vacuum formed on the othercreating lift. Named after physicist Heinrich Gustav Magnus (1802-70).
A marker beacon is a 75 Mhz signal located about 5 miles from the threshold
of a runway. It is a part of an
MEAN SEA LEVEL SEE MSL
METARAcronym in FAA pilot briefings and weather reports simply means an "aviation routine weather report," but nobody seems certain about the original source. The format was introduced by the French on 1 Jan 1968, but was not adopted by USA and Canada until 1 July 1996, and is thought to be a contraction from MÉTéorologique ("Weather") Aviation Règuliére ("Routine"). FAA and NOAA specifically define METAR as "an approximate translation from the French."
MOA SEE SPECIAL USE AIRSPACE
MONOCOQUEType of fuselage design with little or no internal bracing other than bulkheads, where the outer skin bears the main stresses; usually round or oval in cross-section. Additional classifications are (1) Semi-Monocoque, where the skin is reinforced by longerons or bulkheads, but with no diagonal web members, and (2) Reinforced Shell, in which the skin is supported by a complete framework or structural members. French: monocoque,single shell.
MSLMean Sea Level. The average height of the surface of the sea for all stages of tide; used as a reference for elevations, and differentiated from AGL.
NACELLEA streamlined enclosure or housing to protect something such as the crew, engine, or landing gear. French: nacelle,from Latin, navicella,little ship.
NATIONAL AIRSPACE SYSTEM (NAS)The common network of US airspace; air navigation facilities, equipment and services, airports or landing areas; aeronautical charts, information and services; rules, regulations and procedures, technical information, and human resources and material. Included are system components shared jointly with the military.
NDBNon-Directional Beacon. An LF, MF, or UHF radio beacon transmitting non-directional signals whereby the pilot of an aircraft equipped with direction finding equipment can determine his bearing to or from the radio beacon and "home" on or track to or from the station. When the radio beacon is installed in conjuncion with the Instrument Landing System (ILS) marker, it is normally called a Compass Locator.
OVERSHOOTTo land well beyond a runwway or planned spot. Opposite of UNDERSHOOT.
PANTSA popular word for streamlined, non-load bearing fairings to cover landing wheels. Also sometimes called Spats or, when fully enclosing the wheel struts, Skirts.
PARPrecision Approach Radar, a ground-radar-based instrument approach providing both horizontal and vertical guidance
PATTERNThe path of aircraft traffic around an airfield, at an established height and direction. At tower-controlled fields the pattern is supervised by radio (or, in non-radio or emergency conditions by red and green light signals) by air traffic controllers.
PAYLOADAnything that an aircraft carries beyond what is required for its operation during flight, theoretically that from which revenue is derived, such as cargo and passengers.
PCA SEE CONTROLLED AIRSPACE
PHONETICS SEE ALPHABET
PILOT IN COMMAND (PiC)The pilot responsible for the operation and safety of an aircraft during flight time.
PITCH(1) Of the three axes in flight, this specifies the vertical action, the up-and-down movement. Compare ROLL and YAW. (2) The angle of a propeller or rotor blade in relation to its arc; also the distance advanced by a blade in one full rotation.
PITOT TUBEMore accurately but less popularly used, Pitot-Static Tube, a small tube most often mounted on the outward leading edge of an airplane wing (out of the propeller stream) that measures the impact pressure of the air it meets in flight, working in conjuction with a closed, perforated, coaxial tube that measures the static pressure. The difference in pressures is calibrated as air speed by a panel instrument. Named after French scientist Henri Pitot (1695-1771).
POSITIVE CONTROLThe separation of all air traffic within designated airspace by air traffic control.
POWER LOADINGThe GROSS WEIGHT of an airplane divided by the rated horsepower, computed for Standard Air density.
PUSHERA propeller mounted in back of its engine, pushing an aircraft through the air, as opposed to a TRACTOR configuration.
RADIO COMPASS SEE RADIO NAVIGATION
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.
ROLLOf the three axes in flight, this specifies the action around a central point. Compare PITCH and YAW.
ROTARY ENGINEA 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).
ROTORCRAFTA 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.
RUDDERThe movable part of a vertical airfoil which controls the YAW of an aircraft; the fixed part being the FIN.
SAILPLANEAn 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.
SCRAMJETAcronym for supersonic combustion ramjet, in which combustion occurs at supersonic air velocities through the engine.
SCUDA low, foglike cloud layer.
SEAPLANEA 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 STALLAny stall resulting from pulling back too soon and too hard while recovering from any other stall. Usually a HIGH-SPEED or
SERVICE CEILINGThe 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.
SHOULDER-WINGA mid-wing monoplane with its wing mounted directly to the top of the fuselage without use of CABANE STRUTs.
SIDESLIPA 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 SPEEDThe speed at which an aircraft loses altitude, especially in a glide in still air under given conditions of equilibrium.
SKIDToo shallow a bank in a turn, causing an aircraft to slide outward from its ideal turing path.
SLATSMovable vanes or auxiliary airfoils, usually set along the leading edge of a wing but able to be lifted away at certain angles of attack.
SLIPToo steep a bank in a turn, causing an aircraft to slide inward from its ideal turing path.
SLIPSTREAMThe flow of air driven backward by a propeller or downward by a rotor.
SLOTA 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 FLAPA 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 AreaAirspace 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 AreaAirspace designated under part 73 within which no person may operate an aircraft without the permission of the using agency.
Restricted AreaAirspace 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 AreaA 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 FLAPA FLAP built into the underside of a wing, as opposed to a Full Flap wherein a whole portion of the trailing edge is used.
SPOILERA 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 PILOTSpecial FAA certification enabling "budget" pilotry; see LIGHT SPORT AIRCRAFT and LSA feature.
SPONSONA short, winglike protuberance on each side of a seaplane to increase lateral stability.
SQUAWKA four-digit number which is dialed into his transponder by a pilot to identify his aircraft to air traffic controllers
STABILATORA movable horizontal tail that combines the actions of a stabilizer and elevator, increasing longitudinal stability while creating a pitching moment.
STABILIZERThe fixed part of a horizontal airfoil that controls the pitch of an aircraft; the movable part being the ELEVATOR.
STAGGERThe 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 TURNA turn in which the heading of an aircraft changes 3° per second, or 360° in two minutes.
STATIC WIREA clip-on wire used to ground an aircraft by drawing off static electricity, a potential fire hazard, during refueling.
SUA SEE SPECIAL USE AIRSPACE
SUPERSONICSpeed of flight at or greater than Mach 1.0; literally, faster than the speed of sound.
SWEEPBACKA 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-WINGA 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.
TASTrue 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.
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.
TETRAHEDRONGround-based, free-rotating, triangular-shaped wind direction indicator, genrally placed near a runway.
THRUSTThe 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.
TORQUEA twisting, gyroscopic force acting in opposition to an axis of rotation, such as with a turning propeller; aka Torsion.
TOUCH-AND-GOLanding practice wherein an aircraft does not make a full stop after a landing, but proceeds immediately to another take-off.
TRACTORA propeller mounted in front of its engine, pulling an aircraft through the air, as opposed to a PUSHER configuration.
TRAILING EDGEThe rearmost edge of an AIRFOIL.
TRANSPONDERAn 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.
TRIM TABA 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 AIRSPEEDThe 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 NORTHThe northern direction of the axis of the Earth; aka "Map North." GEOGRAPHIC NORTH, as opposed to MAGNETIC NORTH.
TURBOJETAn aircraft having a jet engine in which the energy of the jet operates a turbine that in turn operates the air compressor.
TURBOPROPAn aircraft having a jet engine in which the energy of the jet operates a turbine that drives the propeller.
ULTRALIGHTAn aeronautical vehicle operated for sport or recreational purposes which does not require FAA registration, an airworthiness certificate, nor pilot certification. Primarily single-occupant vehicles, although some two-place vehicles are authorized for training purposes. Operation of an ultralight vehicle in certain airspaces requires authorization from ATC.
UNCONTROLLED AIRSPACEClass G Airspace; airspace not designated as Class A, B, C, D or E.
UNDERCARRIAGEThe landing gear of a land-based aircraft, including struts, frames, and wheels.
UNDERSHOOTTo land short of a runwway or planned landing spot. Opposite is OVERSHOOT.
UNICOMUniversal Communication. A common radio frequency (usually 121.0 mHz) used at uncontrolled (non-tower) airports for local pilot communication.
UPWASHThe slight, upward flow of air just prior to its reaching the leading edge of a rapidly moving airfoil.
UPWIND TURNLong a point of contest among pilots, there is in reality no such thing as far as the airplane is concerned. Proponents claim that airplanes lose air speed when turning upwind, while opponents (and the laws of physics) argue that an airplane, like a boat in a river whose speed is only relative to the water and not the shore, is unaffected within the movement of an air mass and that it loses only ground speed.
USEFUL LOADThe weight of crew, passengers, fuel, baggage, and ballast, generally excluding emergency or portable equipment and ordnance.
VVelocity, now used in defining air speeds:
VA = Maneuvering Speed (max structural speed for full control deflection)QBR>
VD = Max Dive Speed (for certification only)QBR>
VFE = Max Flaps Extended SpeedQBR>
VLE = Max Landing Gear Extended SpeedQBR>
VLO = Max Landing Gear Operation SpeedQBR>
VNE = Never Exceed SpeedQBR>
VNO = Max Structural Cruising Speed QBR>
VS0 = Stalling Speed Landing Configuration QBR>
VS1 = Stalling Speed in a specified ConfigurationQBR>
VX = Best Angle of Climb Speed QBR>
VXSE = Best Angle of Climb Speed, one engine outQBR>
VY = Best Rate of Climb SpeedQBR>
VARIOMETERA panel instrument, often as simple as a tiny ball in a vertical tube, indicating subtle OITCH movements of an aircraft.
VENTRAL FINA fin/rudder extension on the bottom of a fuselage. Opposite of DORSAL FIN.
VENTURI TUBEA small, hourglass-shaped metal tube, usually set laterally on a fuselage in the slipstream to create suction for gyroscopic panel instruments. Now outdated by more sophisticated means.
VFRVisual Flight Rules that govern the procedures for conducting flight under visual conditions. The term is also used in the US to indicate weather conditions that are equal to or greater than minimum VFR requirements. Also used by pilots and controllers to indicate a type of flight plan.
VFR ON TOPFlight in which a cloud ceiling exists but modified VISUAL FLIGHT RULES are in effect if the aircraft travels above the cloud layer.
VISUAL METEOROLOGICAL CONDITIONS (VMC)Meteorological conditions expressed in terms of visibility, distance from clouds, and ceiling equal to or better than specified minima.
VORVHF OmniRange. A ground-based navigation aid transmitting very high frequency (VHF) navigation signals 360° in azimuth, on radials oriented from magnetic north. The VOR periodically identifies itself by Morse Code and may have an additional voice identification feature. Voice features can be used by ATC or FSS for transmitting information to pilots.
VORTACVOR + TACAN (Tactical Air Navigation); combined radio navigation aids.
VSIVertical Speed Indicator. A panel instrument that gauges rate of climb or descent in feet-per-minute (fpm). Also Rate Of Climb Indicator.
WASH-IN, WASH-OUTA method of increasing lift by increasing (Wash-In) or decreasing (Wash-Out) the angle of incidence on the outer part of an airplane wing to counteract the effects of engine torque.
WET COMPASS SEE COMPASS
WINGLETA small, stabilizing, rudderlike addition to the tips of a wing to control or employ air movement.
WING LOADINGThe maximum take-off gross weight of an aircraft divided by its wing area.
YAWOf the three axes in flight, this specifies the side-to-side movement of an aircraft on its vertical axis, as in skewing. Compare PITCH and ROLL.
YOKEThe control wheel of an aircraft, akin to a automobile steering wheel.