Reference

Aviation glossary

Every technical term used elsewhere in the manual, defined in the fewest words that remain honest. Click a term for the full definition.

86 terms

Accident Chain Linked sequence of failures RISK · Risk Management: The set of individually manageable errors, hazards, and decisions that link together to produce an accident.
ADM Aeronautical Decision-Making RISK · Risk Management: The systematic approach to consistently determining the best course of action in response to a given set of circumstances.
AGL Above Ground Level WX · Meteorology: Altitude measured from the ground directly below the aircraft, as opposed to sea level.
Ailerons Roll control surfaces AERO · Aerodynamics: The hinged control surfaces on the outboard trailing edge of each wing that produce roll by differentially changing lift.
Airfoil Wing cross-section AERO · Aerodynamics: The two-dimensional shape of a wing seen from the side; its geometry sets the lift and drag characteristics.
Alternate Airport Filed backup destination OPS · Strategy & Tactics: An airport nominated on the flight plan where the flight can land if the intended destination becomes unavailable.
Angle of Attack Wing-to-wind angle (α) AERO · Aerodynamics: The angle between the wing's chord line and the relative wind. The wing stalls when α exceeds its critical value, regardless of airspeed or attitude.
ATIS Automatic Terminal Information Service NAV · Navigation: A continuously broadcast recording of routine airport information — weather, active runways, NOTAMs — that pilots monitor before contacting the tower.
Best Glide V_G AERO · Aerodynamics: The airspeed that produces the maximum lift-to-drag ratio, and therefore the flattest engine-out glide.
Callout Verbalized flight parameter CRM · Crew & Team Coordination: A standardized spoken statement of a flight state — 'V1', '500 above', 'stable' — that shares situation awareness and forces cross-checking.
Camber Airfoil curvature AERO · Aerodynamics: The curvature of the mean line of an airfoil; positive camber shifts the zero-lift angle so the wing produces lift at 0° pitch.
Carburetor Ice Induction icing in the venturi SYS · Mechanical Systems: Ice that forms in a carburetor's venturi from the temperature drop of expanding fuel-air mixture, possible even in warm outside air.
CAS Calibrated Airspeed SYS · Mechanical Systems: Indicated airspeed corrected for instrument and position error.
CDI Course Deviation Indicator NAV · Navigation: The needle that shows displacement from a selected VOR radial or ILS localizer course.
Ceiling Lowest broken/overcast WX · Meteorology: The height above ground of the lowest broken (BKN) or overcast (OVC) layer, or the vertical visibility into an obscuration.
Challenge-Response Checklist discipline CRM · Crew & Team Coordination: A checklist technique where one crewmember reads the item and the other verifies and responds.
Chord Wing reference line AERO · Aerodynamics: The straight line from the leading edge to the trailing edge of an airfoil; angle of attack is measured from it.
Constant-Speed Propeller Governed pitch propeller SYS · Mechanical Systems: A propeller whose blade pitch is continuously adjusted by a governor to hold a selected RPM regardless of power or airspeed.
Continuation Bias Plan-continuation error RISK · Risk Management: The tendency to press on with the original plan in the face of mounting cues that it is no longer safe.
Crab Wind-correction heading NAV · Navigation: A heading offset into the wind that keeps the aircraft tracking a desired ground course.
CRM Crew Resource Management CRM · Crew & Team Coordination: The discipline of using all available resources — people, information, equipment — to manage a flight safely.
Crosswind Component Wind perpendicular to runway AERO · Aerodynamics: The component of the wind vector perpendicular to the runway centerline, computed from wind speed and the angle between wind and runway.
Dead Reckoning Heading + time + wind NAV · Navigation: Navigation computed from a known starting point using heading, airspeed, wind, and elapsed time.
Density Altitude Pressure altitude + temperature correction WX · Meteorology: The pressure altitude corrected for non-standard temperature; the altitude at which the airplane 'thinks' it is.
Dew Point Saturation temperature WX · Meteorology: The temperature at which the air, cooled at constant pressure, becomes saturated with water vapor.
Displacement Taxi Floats fully in the water HYDRO · Hydrodynamics & Floatplanes: Slow floatplane taxi where the floats displace their weight in water — the safe, low-speed mode for maneuvering in confined areas.
Diversion Course change to a new destination OPS · Strategy & Tactics: A pre-briefed decision to abandon the planned destination and proceed to an alternate airport because conditions or aircraft state warrant it.
Drag Aerodynamic resistance AERO · Aerodynamics: The component of the aerodynamic force parallel to and opposite the direction of flight; the sum of parasite and induced drag.
Empennage Tail assembly SYS · Mechanical Systems: The tail structure of an aircraft — horizontal stabilizer, elevator, vertical stabilizer, and rudder — that provides pitch and yaw stability and control.
Flaps High-lift devices AERO · Aerodynamics: Trailing-edge devices that increase wing camber (and sometimes area) to raise the coefficient of lift for takeoff and landing.
Flare Landing round-out AERO · Aerodynamics: The pitch-up maneuver at the end of an approach that arrests the descent rate to arrive on the runway at minimum vertical speed.
Fuel Reserve Required unburned fuel on landing OPS · Strategy & Tactics: The minimum fuel that must remain in the tanks at the intended destination — 30 min VFR day, 45 min VFR night, 45 min IFR — plus flight to any required alternate.
Fuselage Aircraft body SYS · Mechanical Systems: The main body of an aircraft to which wings, empennage, and landing gear attach and which houses crew, passengers, and payload.
Glassy Water Mirror-smooth surface HYDRO · Hydrodynamics & Floatplanes: A water surface with no ripples, which defeats depth perception on landing and requires a specific power-on, controlled-descent technique to a fixed pitch attitude.
Go-Around Discontinued approach OPS · Strategy & Tactics: A discontinued approach in which the pilot applies full power, arrests the descent, and repositions to try again.
Ground Effect Wingtip vortex suppression near surface AERO · Aerodynamics: The reduction in induced drag and increase in effective lift that occurs when a wing operates within roughly one wingspan of the surface.
Gyroscopic Precession Force applied 90° later in rotation AERO · Aerodynamics: A property of a spinning rotor whereby an applied force produces a reaction 90° later in the direction of rotation.
Headwind Wind component opposing flight WX · Meteorology: The component of the wind vector aligned against the direction of flight; increases required airspeed for a given groundspeed.
IAS Indicated Airspeed SYS · Mechanical Systems: The airspeed shown on the cockpit indicator, uncorrected for instrument, position, compressibility, or density error.
IFR Instrument Flight Rules NAV · Navigation: The set of regulations under which aircraft are operated with an ATC clearance in instrument meteorological conditions.
IMSAFE Personal readiness checklist RISK · Risk Management: A mnemonic — Illness, Medication, Stress, Alcohol, Fatigue, Emotion — for pilot self-assessment before every flight.
Isobar Line of equal pressure WX · Meteorology: A line on a surface analysis chart connecting points of equal barometric pressure.
Knot Nautical mile per hour NAV · Navigation: A unit of speed equal to one nautical mile per hour; the standard airspeed and windspeed unit in aviation.
L/D Ratio Lift over drag AERO · Aerodynamics: The dimensionless ratio of lift to drag; its maximum defines the most efficient airspeed for the airframe.
Lapse Rate Temperature change with altitude WX · Meteorology: The rate at which atmospheric temperature decreases with height; standard is about 2 °C per 1000 ft.
Load Factor g-loading (n) AERO · Aerodynamics: The ratio of lift to aircraft weight; a level 60° banked turn produces a load factor of 2 g.
Magnetic Variation Angle between true north and magnetic north NAV · Navigation: The local angular difference between true north and magnetic north, shown on sectional charts as isogonic lines.
Magneto Self-contained ignition SYS · Mechanical Systems: An engine-driven generator that produces the high-voltage spark for the ignition system, independent of the aircraft's electrical system. Certified engines carry two.
Manifold Pressure Absolute intake-manifold pressure SYS · Mechanical Systems: The absolute pressure in the engine's intake manifold, in inches of mercury; the primary power gauge on a constant-speed installation.
METAR Routine surface weather report WX · Meteorology: A coded hourly observation of surface weather at an airport.
Mixture Fuel-to-air ratio control SYS · Mechanical Systems: The cockpit control that varies the fuel-to-air ratio delivered to the engine, leaned as air density decreases with altitude.
MSL Mean Sea Level WX · Meteorology: Altitude measured from the long-term average level of the sea, the reference used on aeronautical charts.
NOTAM Notice to Air Missions NAV · Navigation: A time-critical notice of a change to the National Airspace System — runway closures, unlighted obstructions, unusable navaids — that a pilot must review before flight.
Pattern Traffic pattern circuit NAV · Navigation: The standardized rectangular circuit — departure, crosswind, downwind, base, final — flown around an airport at pattern altitude.
PAVE Preflight risk checklist RISK · Risk Management: A mnemonic — Pilot, Aircraft, enVironment, External pressures — for structured preflight risk assessment.
Personal Minimums Self-imposed operating limits OPS · Strategy & Tactics: A pilot's own limits — ceiling, visibility, crosswind, night currency — set higher than regulatory minimums to preserve margin for actual proficiency.
Pilotage Navigation by landmarks NAV · Navigation: Navigation by direct visual reference to identifiable features on the ground — rivers, roads, towns, lakes — cross-checked against the sectional chart.
Pitot Tube Ram-air probe SYS · Mechanical Systems: A forward-facing tube that captures total pressure for the airspeed indicator.
Plow Taxi Nose-high, bow-wave taxi HYDRO · Hydrodynamics & Floatplanes: The transitional, high-drag floatplane attitude between displacement and step taxi — nose high, bow wave large.
Porpoising Pitch oscillation on the step HYDRO · Hydrodynamics & Floatplanes: An unstable pitch oscillation of a floatplane on the step, caused by incorrect pitch attitude; ignored, it can flip the aircraft.
Radial Bearing from a VOR NAV · Navigation: A magnetic bearing measured outward from a VOR station.
Rudder Yaw control surface SYS · Mechanical Systems: The hinged control surface on the vertical stabilizer that produces yaw and coordinates turns.
Sectional Chart VFR aeronautical chart · 1:500,000 NAV · Navigation: The standard VFR pilot chart, printed at a scale of 1:500,000, showing terrain, airspace, airports, obstacles, and navaids.
Squawk Transponder code assignment NAV · Navigation: The four-digit octal code entered in the transponder to identify an aircraft to ATC's secondary surveillance radar.
SRM Single-Pilot Resource Management CRM · Crew & Team Coordination: CRM adapted for the single pilot — deliberate workload management, use of automation and ATC as crew, and self-monitoring of state and situation awareness.
Stall Lift collapse at α_crit AERO · Aerodynamics: The loss of lift that occurs when a wing exceeds its critical angle of attack, regardless of airspeed or attitude.
Standard Atmosphere ISA · 29.92" Hg / 15 °C at SL WX · Meteorology: The international reference atmosphere used to calibrate instruments and performance data.
Static Port Ambient pressure port SYS · Mechanical Systems: A flush port that senses undisturbed atmospheric pressure for the altimeter, VSI, and ASI.
Step (seaplane) Planing notch on the float HYDRO · Hydrodynamics & Floatplanes: The small transverse notch on the underside of each float where water separates cleanly at planing speed, reducing wetted area and drag.
Step Taxi Floatplane on-step HYDRO · Hydrodynamics & Floatplanes: A floatplane taxi technique that lifts the hulls onto the planing step to reduce water drag; enables the takeoff run and shortens water time in choppy conditions.
Sterile Cockpit No non-essential talk CRM · Crew & Team Coordination: A discipline that prohibits non-essential conversation during critical phases of flight — typically below 10,000 ft, and always during taxi, takeoff, approach, and landing.
TAF Terminal Aerodrome Forecast WX · Meteorology: A 24- to 30-hour forecast of weather conditions at an airport, issued four times per day.
TAS True Airspeed SYS · Mechanical Systems: Calibrated airspeed corrected for air density; the aircraft's speed through the surrounding air mass.
Threat and Error Management TEM framework CRM · Crew & Team Coordination: A model for viewing operations as a stream of threats (external) and errors (crew) that must be anticipated, detected, and mitigated before they become undesired aircraft states.
Torque Propeller reaction on airframe SYS · Mechanical Systems: The rotational reaction of the airframe to the propeller's rotation; one of four left-turning tendencies at high power and low airspeed.
Transponder Radar identification transceiver NAV · Navigation: An airborne transceiver that replies to secondary surveillance radar with a coded identifier and (Mode C) pressure altitude.
Trim Neutralized control force SYS · Mechanical Systems: A small auxiliary surface adjusted to hold the primary control at a desired position without pilot force.
V_NE Never-exceed speed AERO · Aerodynamics: The maximum airspeed at which the airframe may be operated in any configuration.
V_S Stall speed, 1 g AERO · Aerodynamics: The published stall speed in a specified configuration at 1 g and gross weight.
V-Speeds Airspeed references AERO · Aerodynamics: The standardized airspeed markers used to fly an aircraft — V_S, V_X, V_Y, V_A, V_NO, V_NE, and others defined in the POH.
VFR Visual Flight Rules NAV · Navigation: The set of regulations under which aircraft are operated by outside visual reference, in weather that meets or exceeds VFR minimums.
VOR VHF Omnidirectional Range NAV · Navigation: A ground-based VHF navigation aid that broadcasts 360 discrete radials.
VSI Vertical Speed Indicator SYS · Mechanical Systems: An instrument that displays the rate of change of static pressure as feet per minute of climb or descent.
Wake Turbulence Wingtip vortex from generating aircraft AERO · Aerodynamics: The pair of counter-rotating vortices trailing from the wingtips of a lift-producing aircraft; a hazard proportional to the generator's weight, wingspan, and speed.
Water Rudder Retractable float rudder HYDRO · Hydrodynamics & Floatplanes: A small retractable rudder at the aft end of each float, used for slow-speed steering; must be retracted before takeoff and landing.
Yoke Pitch and roll control SYS · Mechanical Systems: The steering-wheel-shaped primary flight control that moves the elevator (pitch) and ailerons (roll).