GLOSSARY

FAA terms, defined and cited

Every definition is plain English and carries the exact FAA passage it comes from, so you can check it against the source. Spans all 13 knowledge tests.

55 terms

Above Ground Level (AGL)AGLAirspaceAn altitude measured upward from the terrain directly below the aircraft. Cloud ceilings and Part 107 altitude limits are stated in feet AGL.
Aeronautical Decision-Making (ADM)ADMAcronyms & AbbreviationsA structured way of thinking through the safest course of action in flight, weighing hazards and risk instead of reacting on instinct.
Angle of AttackAOA, AoAAircraft SystemsThe angle between the wing's chord line and the oncoming relative wind. Lift rises with angle of attack until the critical angle, where the wing stalls regardless of airspeed.
Best Angle of Climb Speed (VX)VX, VxAircraft SystemsThe speed that produces the most altitude gained per unit of horizontal distance, used to clear an obstacle on a short-field takeoff.
Best Rate of Climb Speed (VY)VY, VyAircraft SystemsThe speed that produces the most altitude gained per unit of time, used for a normal climb to cruise altitude.
Best Single-Engine Rate of Climb Speed (VYSE)VYSE, blue lineAircraft SystemsIn a light twin, the speed that gives the best rate of climb, or least sink, with one engine inoperative; it is marked by the blue radial line.
Center of Gravity (CG)CGLoading & PerformanceThe point where the aircraft's weight is considered to act, and where it would balance if suspended; its position must stay within the approved forward and aft limits.
Class A AirspaceClass AAirspaceThe high-altitude controlled airspace running from 18,000 feet MSL up through FL600, where every flight must be operated under instrument flight rules.
Class B AirspaceClass B, Bravo airspaceAirspaceThe controlled airspace around the busiest airports, shaped like an upside-down wedding cake, that requires an ATC clearance before you enter.
Class C AirspaceClass C, Charlie airspaceAirspaceControlled airspace around busy airports with a tower and radar approach control, where you must establish two-way radio contact before entering.
Class D AirspaceClass D, Delta airspaceAirspaceControlled airspace surrounding a tower-equipped airport, typically up to 2,500 feet above the field, that requires two-way radio contact before you enter.
Class E AirspaceClass E, Echo airspaceAirspaceAll the controlled airspace that is not Class A, B, C, or D, providing room to safely separate and control IFR traffic across most of the country.
Class G AirspaceClass G, Golf airspace, uncontrolled airspaceAirspaceUncontrolled airspace where ATC provides no separation service, extending from the surface up to the base of the overlying Class E airspace.
Complex AirplaneRegulations & CertificationAn airplane with retractable landing gear, flaps, and a controllable pitch propeller; operating one as pilot in command requires a one-time instructor endorsement.
Crew Resource Management (CRM)CRMAcronyms & AbbreviationsThe use of all available resources, including people, equipment, and information, to manage a flight safely; the single-pilot version is called single-pilot resource management.
Declaration of ComplianceDOCRegulations & CertificationA record a drone producer submits to the FAA attesting that a design meets the applicable remote identification or operations-over-people requirements.
Density AltitudeDAWeatherPressure altitude corrected for temperature; high density altitude means thin air, which cuts engine power, propeller thrust, and wing lift so the aircraft performs as if much higher.
Dew Point and Temperature Spreaddewpoint, temperature dew point spreadWeatherThe dew point is the temperature at which air becomes saturated; a small gap between temperature and dew point signals high humidity and the chance of fog or low clouds.
High-Performance AirplaneRegulations & CertificationAn airplane with an engine of more than 200 horsepower; acting as pilot in command of one requires a one-time instructor endorsement.
HypoxiaAircraft SystemsA shortage of oxygen reaching the body's tissues, common at altitude, that impairs judgment and coordination and can occur before a pilot notices the symptoms.
IMSAFE ChecklistIMSAFEAcronyms & AbbreviationsA personal fitness-for-flight self-check covering Illness, Medication, Stress, Alcohol, Fatigue, and Emotion that a pilot runs before deciding to fly.
Instrument Flight Rules (IFR)IFRRegulations & CertificationThe rules for flying by reference to instruments and electronic navigation when outside visual reference is not safe, used throughout the clouds and in low visibility.
Instrument Meteorological Conditions (IMC)IMC weatherWeatherWeather below the minimums for visual flight, so poor in visibility, cloud clearance, or ceiling that flight must be conducted under instrument flight rules.
Land and Hold Short Operations (LAHSO)LAHSOAirspaceAn ATC procedure used when takeoffs and landings happen on intersecting runways, asking a pilot to land and stop before a crossing runway or point.
LatitudeparallelsNavigation & ChartsThe measurement of position north or south of the equator, drawn as parallels and given in degrees, minutes, and seconds.
Load FactorG load, GsAircraft SystemsThe ratio of the load on the wings to the aircraft's weight, expressed in Gs; it climbs steeply in steep turns and pull-ups and raises the stall speed.
LongitudemeridiansNavigation & ChartsThe measurement of position east or west of the Prime Meridian at Greenwich, drawn as meridians and given in degrees, minutes, and seconds.
Magnetic Variationvariation, magnetic vs trueNavigation & ChartsThe angular difference between true north and magnetic north at a location; pilots apply it to convert between true and magnetic courses when navigating.
Maneuvering Speed (VA)VA, design maneuvering speedAircraft SystemsThe speed below which a single full deflection of one flight control will stall the wing before it overstresses the airframe, so it is the target speed for turbulence.
Mean Sea Level (MSL)MSLAirspaceAn altitude measured upward from average sea level. Airspace floors and ceilings, terrain, and obstacle heights on charts are usually given in feet MSL.
METARAviation Routine Weather ReportWeatherA coded report of current surface weather observed at an airport, giving wind, visibility, clouds, temperature, dew point, and altimeter setting.
Military Operations AreaMOAAirspaceAirspace with defined limits used to separate military training activity from IFR traffic; VFR pilots may enter but should stay alert for fast-moving military aircraft.
Minimum Control Speed (VMC)VMC, Vmc, red lineAircraft SystemsIn a light twin, the slowest speed at which directional control can be kept after the critical engine fails with the good engine at takeoff power; marked by the red radial line.
Notice to Air Missions (NOTAM)NOTAM, Notice to AirmenAirspaceA time-critical notice about conditions or changes, such as closed runways or restrictions, that pilots must review during flight planning because it is too new for charts.
PAVE ChecklistPAVEAcronyms & AbbreviationsA preflight risk framework that sorts hazards into Pilot, Aircraft, enVironment, and External pressures so a pilot can weigh each area before departing.
Pilot Weather Report (PIREP)PIREPWeatherA report of weather actually encountered in flight, such as turbulence, icing, or cloud tops, that pilots pass to controllers or flight service to help others.
Pressure AltitudePAWeatherThe altitude read when the altimeter is set to the standard 29.92 inches of mercury; it is the starting point for computing density altitude and performance.
Prohibited AreaP-areaAirspaceAirspace where flight is not allowed at all, established for security or national welfare reasons and charted with a P and a number, such as P-40.
Remote Identification (Remote ID)Remote IDRegulations & CertificationThe requirement for most drones to broadcast identification and location while flying, working like a digital license plate for unmanned aircraft.
Restricted AreaR-areaAirspaceAirspace containing hazards such as artillery or missile activity where flight is not wholly banned but is subject to restrictions and often needs authorization from the controlling agency.
Runway IncursionAirspaceAny event on the runway surface, involving an aircraft, vehicle, person, or object, that creates a collision hazard or a loss of required separation from an aircraft taking off or landing.
Sectional Chartsectional aeronautical chartNavigation & ChartsThe most common VFR chart, at a scale of 1:500,000, showing terrain, airports, airspace, and navigation aids for visual cross-country flying.
Small Unmanned AircraftsUAS, small UAS, droneRegulations & CertificationUnder Part 107, a drone that weighs less than 55 pounds at takeoff, counting everything carried on board or attached to it.
Spatial DisorientationAircraft SystemsA loss of awareness of the aircraft's attitude and position caused by misleading sensory signals, especially when a pilot loses outside visual reference in cloud or at night.
Special Use AirspaceSUA, SAOAirspaceAirspace set aside where certain activities must be confined or where limits are placed on aircraft not taking part, including prohibited, restricted, warning, and military operations areas.
Stall Speed in Landing Configuration (VSO)VSO, VS0Aircraft SystemsThe power-off stall speed with gear and flaps down at maximum landing weight; it is the bottom of the white arc on the airspeed indicator.
Standard AtmosphereISA, International Standard AtmosphereWeatherAn agreed reference atmosphere used to calibrate instruments and compare performance, defined at sea level as 15 degrees Celsius and 29.92 inches of mercury.
Temporary Flight RestrictionTFRAirspaceA short-notice restriction on flight in a defined area, published by NOTAM to protect people, property, or events such as disasters, VIP movements, or major sporting events.
Terminal Aerodrome Forecast (TAF)TAFWeatherA forecast of expected weather within about five statute miles of an airport, written in the same code as a METAR and typically valid for 24 to 30 hours.
Useful LoadLoading & PerformanceThe weight an aircraft can carry beyond its empty weight, including crew, passengers, baggage, usable fuel, and drainable oil; it is gross weight minus empty weight.
Visual Flight Rules (VFR)VFRRegulations & CertificationThe rules for flying by outside visual reference, which set the ceiling and visibility a pilot must have to navigate and see and avoid other traffic.
Visual Meteorological Conditions (VMC)VMC weatherWeatherWeather good enough, in terms of visibility, distance from clouds, and ceiling, to meet or beat the minimums required for flight under visual flight rules.
Wake Turbulencewingtip vorticesAircraft SystemsThe rotating cores of air, or wingtip vortices, shed by a wing producing lift; they sink and drift, so pilots stay above and upwind of a preceding heavy aircraft's path.
Warning AreaW-areaAirspaceAirspace extending from three nautical miles off the coast that contains activity possibly hazardous to aircraft, over waters where the United States does not have sole jurisdiction.
Weight and BalanceLoading & PerformanceThe process of checking that an aircraft is loaded within its maximum weight and its center of gravity limits, which every pilot must confirm before flight.