This glossary defines the 150 aviation terms a student pilot actually meets, in the order the alphabet puts them, each in one or two sentences and each written to be useful in a cockpit rather than impressive on a page. Where a term comes from a regulation, the regulation is cited by number so you can read the source yourself.
It is built for the first hundred hours: the words your instructor uses on a first lesson, the ones on the private pilot written exam, the ones a designated examiner will expect you to define on an oral, and the ones that appear on a sectional chart or in a weather report. It is part of our student pilot resources, alongside the paperwork, the medical and the written exam. If a term here is new, that is normal. Nobody learns this vocabulary from a list; you learn it by hearing it used and then looking it up afterwards, which is exactly what this page is for.
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A · B · C · D · E · F · G · H · I · J · K · L · M · N · O · P · Q · R · S · T · U · V · W · X · Y · Z
A
Above Ground Level (AGL)
Height measured from the surface directly beneath the aircraft rather than from sea level. Traffic pattern altitudes, minimum safe altitudes and cloud clearances near the ground are usually expressed in feet AGL.
ADS-B
Automatic Dependent Surveillance-Broadcast, a system in which an aircraft transmits its own GPS-derived position, altitude and velocity to air traffic control and to nearby aircraft. ADS-B Out equipment is required in most controlled airspace in the United States, and ADS-B In receives traffic and weather.
Aeronautical Information Manual (AIM)
The FAA's official guide to flight information and air traffic control procedures in the United States. It is not regulatory in itself, but it explains how the regulations are applied and is a primary study source for both written and oral exams.
Aileron
A hinged control surface on the trailing edge of each wing, near the tip, that moves in opposite directions to roll the aircraft about its longitudinal axis. Ailerons are operated by turning the yoke or moving the stick sideways.
Airfoil
The cross-sectional shape of a wing, propeller blade or tail surface, designed to produce a useful aerodynamic force as air flows over it. The same shape produces lift on a wing and thrust on a propeller.
Airspeed Indicator
The instrument that displays the aircraft's speed through the air, driven by the difference between ram air pressure from the pitot tube and static pressure. Its colored arcs mark the stall speeds, the normal operating range, the flap limit and the never-exceed speed.
Airworthiness Certificate
The FAA document certifying that an aircraft conforms to its approved type design and is in a condition for safe operation. It must be carried aboard the aircraft and displayed where passengers or crew can see it.
Angle Of Attack
The angle between the wing's chord line and the oncoming airflow. It is the single most important idea in basic aerodynamics, because a wing always stalls at the same critical angle of attack regardless of airspeed, weight or attitude.
ATIS
Automatic Terminal Information Service, a continuous recorded broadcast at busier airports giving the current weather, runways in use, approaches in use and any relevant notices. Each broadcast carries a letter code, and you tell the controller which letter you have.
Attitude Indicator
The gyroscopic instrument showing the aircraft's pitch and bank relative to an artificial horizon. It is the primary instrument for controlling the aircraft when there is no visible natural horizon.
B
Base Leg
The leg of the traffic pattern flown perpendicular to the landing runway, between the downwind leg and final approach. It is where most of the descent planning for the landing is done.
BasicMed
An alternative to holding an FAA medical certificate for certain private flying, set out in 14 CFR 61.113(i) and Part 68. It requires a valid US driver's license, a physical examination using an FAA checklist and an online medical education course, and it carries limits on aircraft size, altitude and speed.
Bernoulli's Principle
The physical relationship stating that as the speed of a fluid increases its static pressure decreases. It is one of the explanations of how a wing produces lift, alongside the change of momentum imparted to the air by the wing deflecting it downward.
Best Glide Speed
The airspeed that produces the greatest distance traveled for a given loss of altitude with the engine at idle or stopped. It is a specific number in the Pilot's Operating Handbook, 73 knots indicated in a Piper Warrior, and it is the first thing a pilot pitches for after an engine failure.
Block Time
In flight training, a quantity of aircraft or instruction time bought in advance, often at a reduced rate. In airline usage it means the time from when the aircraft moves off the gate to when it stops at the destination gate.
Briefing
The pre-flight review of weather, notices, routing and fuel, and in training also the discussion of what the lesson will cover. 14 CFR 91.103 requires a pilot to become familiar with all available information concerning a flight before departing.
C
Carburetor Heat
A control that directs warmed air into the carburetor to prevent or clear ice formed by the pressure and temperature drop in the venturi. Carburetor ice can form in humid air at surprisingly warm outside temperatures, particularly at low power settings.
Ceiling
The height above ground of the lowest layer of cloud reported as broken or overcast, or the vertical visibility into an obscuration. It is one of the two numbers, with visibility, that decides whether a VFR flight can legally depart.
Center Of Gravity
The point at which the aircraft's weight is considered to act, and about which it balances. Every aircraft has a forward and aft center of gravity limit, and loading outside that range affects stability and control long before it affects anything else.
Certificated Flight Instructor (CFI)
A pilot holding an FAA flight instructor certificate under 14 CFR 61.183, authorized to give flight and ground instruction and to make the logbook endorsements a student needs. A CFII additionally instructs for the instrument rating, and an MEI for multi-engine.
Chandelle
A commercial pilot maneuver consisting of a 180-degree climbing turn that trades airspeed for the maximum altitude gain, entered at about 30 degrees of bank and finished wings level just above the stall. It is tested on the commercial practical test.
Checkride
The colloquial name for an FAA practical test, consisting of an oral examination followed by a flight, conducted by a designated pilot examiner or an FAA inspector against the Airman Certification Standards for the certificate sought.
Class A Airspace
Airspace from 18,000 feet MSL up to and including flight level 600 over the United States. All operations must be conducted under instrument flight rules, so a VFR pilot never enters it.
Class B Airspace
The airspace surrounding the busiest airports, shaped in tiers like an upside-down wedding cake. An explicit ATC clearance is required to enter, and the Los Angeles Class B is the airspace whose shelves sit above Van Nuys.
Class C Airspace
Airspace around moderately busy airports with a control tower and radar service. Two-way radio communication must be established before entry, and a transponder with altitude reporting is required.
Class D Airspace
Airspace around an airport with an operating control tower but without radar-based Class C or B service, typically extending to about 2,500 feet above the field. Two-way radio communication must be established before entry. Van Nuys is a Class D airport.
Class E Airspace
Controlled airspace that is not Class A, B, C or D. It covers most of the airspace above 1,200 feet AGL across the country and steps down to 700 feet AGL or to the surface near many airports.
Class G Airspace
Uncontrolled airspace, where air traffic control exercises no authority over VFR traffic. It typically occupies the lowest few hundred or thousand feet in areas away from airports and airways, and has its own lower VFR weather minimums.
Controlled Airspace
A general term for Class A, B, C, D and E airspace, within which air traffic control service is provided to IFR flights and, depending on the class, to VFR flights. The term describes where ATC has authority, not where you need permission to fly.
Cross-Country
Flight to a point other than the departure airport, logged according to the definitions in 14 CFR 61.1. For most private and commercial requirements the landing must be at a point more than 50 nautical miles straight-line distance from the original departure point.
D
Density Altitude
Pressure altitude corrected for non-standard temperature, and the number that actually determines aircraft performance. On a hot afternoon at Van Nuys the density altitude can be several thousand feet above the field elevation, lengthening the takeoff roll and flattening the climb.
Designated Pilot Examiner (DPE)
A private individual authorized by the FAA to conduct practical tests and issue certificates. DPEs charge their own fee, commonly in the region of $800 to $1,000 in Southern California, and their availability often drives checkride scheduling.
Dew Point
The temperature at which the air becomes saturated and moisture begins to condense. When the temperature and dew point converge, expect cloud, fog or visible moisture, and in a carbureted engine consider carburetor ice.
Discovery Flight
An introductory flight lesson in which the prospective student flies the aircraft from the left seat with a flight instructor beside them. It is genuine dual instruction and is logged toward a certificate from the first flight.
Downwind Leg
The leg of the traffic pattern flown parallel to the landing runway in the opposite direction to landing, normally at traffic pattern altitude. Most pre-landing checks and the initial power reduction happen here.
Drag
The aerodynamic force opposing the aircraft's motion through the air. It has two components: parasite drag, which rises with speed, and induced drag, which is a by-product of producing lift and rises as speed falls.
E
Elevator
The hinged control surface on the horizontal tail that pitches the nose up and down about the lateral axis. Some aircraft use a stabilator, a single all-moving surface, in place of a fixed stabilizer and elevator.
Emergency Locator Transmitter (ELT)
A self-contained radio beacon that activates on impact and transmits a distress signal to aid search and rescue. 14 CFR 91.207 governs when one is required and how often its battery must be replaced or recharged.
Empennage
The tail assembly of the aircraft, comprising the vertical fin and rudder and the horizontal stabilizer and elevator or stabilator. Its job is stability in pitch and yaw as well as control.
Empty Weight
The weight of the aircraft including unusable fuel, full operating fluids and installed equipment, but without usable fuel, occupants or baggage. It differs between individual airframes of the same model and is taken from that aircraft's own weight and balance record.
Endorsement
A signed and dated entry made in a pilot's logbook by an authorized instructor, certifying that specific training has been given or that the pilot is authorized for a specific operation. Solo flight, complex aircraft, high-performance aircraft and tailwheel aircraft all require endorsements.
F
Final Approach
The last leg of the traffic pattern, flown along the extended runway centerline toward the landing threshold. A stable approach on final, with the airspeed, descent rate and alignment settled early, is the single best predictor of a good landing.
Fixed Base Operator (FBO)
A business at an airport providing services to general aviation such as fuel, parking, hangarage, maintenance and passenger facilities. At a busy field like Van Nuys there are several, each with different services and fees.
Flaps
Movable surfaces on the inboard trailing edge of the wing that increase lift and drag when extended, allowing a steeper and slower approach. Each aircraft has a maximum flaps-extended speed, marked as the top of the white arc on the airspeed indicator.
Flare
The gradual raising of the nose in the last few feet before touchdown, which arrests the descent and sets the landing attitude. The most common landing fault in training is flaring on height judgment rather than on the sight picture down the runway.
Flight Plan
A filed record of a planned flight including route, altitude, timing, fuel and souls on board. A VFR flight plan is optional and is used for search and rescue purposes; an IFR flight plan is required for flight under instrument flight rules.
Flight Review
The recurrent training required by 14 CFR 61.56, consisting of at least one hour of flight training and one hour of ground training with an authorized instructor within the preceding 24 calendar months. Without a current flight review a pilot may not act as pilot in command.
Flight Service Station
The FAA facility providing pilot weather briefings, flight plan filing and en route advisory services. It is reached by telephone, online or on the radio in flight, and it is not the same thing as air traffic control.
Fuel Sump
A low point in each fuel tank and in the fuel system fitted with a drain valve, from which a sample is taken during the preflight inspection. The sample is checked for water, sediment and the correct fuel color and smell.
G
Glide Ratio
The horizontal distance an aircraft travels for each unit of altitude lost with the engine at idle, expressed as a ratio such as 10 to 1. It is at its best at the published best glide speed and degrades at any other speed.
Glideslope
The vertical guidance component of an instrument landing system, defining the correct descent path to the runway. The term is also used loosely for the visual descent path shown by a PAPI or VASI light system.
Global Positioning System (GPS)
Satellite-based navigation giving position, groundspeed and track. In aviation, only equipment approved for the purpose may be used as a primary means of IFR navigation, and a handheld or tablet GPS is supplemental rather than primary.
Go-Around
The decision to abandon an approach and climb away for another attempt. It is a normal maneuver rather than a failure, and the willingness to make the decision early is one of the things instructors work hardest to build.
Ground Effect
The reduction in induced drag that occurs within roughly one wingspan of the surface, caused by the ground interfering with the wingtip vortices. It makes the aircraft feel as though it wants to float in the last few feet of the landing.
Groundspeed
The aircraft's speed over the ground, equal to true airspeed adjusted for wind. It is the number that determines how long a flight takes and how much fuel it needs, and it is what pivotal altitude is calculated from.
H
Heading
The direction the aircraft's nose is pointing, expressed in degrees magnetic. It is not the same as track, which is the path actually followed over the ground once the wind has pushed the aircraft sideways.
Heading Indicator
The gyroscopic instrument showing the aircraft's heading, steadier and easier to read than the magnetic compass. In a traditional panel it drifts over time and must be reset against the compass in straight and level flight.
High-Performance Airplane
An airplane with an engine of more than 200 horsepower. 14 CFR 61.31(f) requires ground and flight training and a logbook endorsement before acting as pilot in command of one.
Hold Short Line
The painted marking on a taxiway, two solid and two dashed yellow lines, beyond which an aircraft may not pass toward an active runway without a clearance. Crossing it without clearance is a runway incursion.
Hypoxia
A deficiency of oxygen reaching the tissues, which at altitude degrades judgment and vision before the pilot notices anything is wrong. 14 CFR 91.211 sets the altitudes at which supplemental oxygen becomes required.
I
IACRA
The Integrated Airman Certification and Rating Application, the FAA's online system for applying for certificates and ratings. Your student pilot certificate application and every subsequent certificate application is submitted through it.
Indicated Airspeed
The speed shown on the airspeed indicator, uncorrected for instrument or position error or for air density. It is the number the aircraft's handling actually follows, which is why stall speeds and limit speeds are expressed in it.
Induced Drag
The drag created as a by-product of producing lift, associated with the wingtip vortices. It increases as airspeed decreases, which is why slow flight requires noticeably more power than cruise.
Instrument Flight Rules (IFR)
The set of rules governing flight by reference to instruments, under an ATC clearance, without the requirement to remain clear of cloud. Flying IFR requires an instrument rating and a suitably equipped aircraft.
Instrument Landing System (ILS)
A ground-based precision approach system providing both lateral guidance from a localizer and vertical guidance from a glideslope. It allows an approach to be flown to a low decision height in poor visibility.
Instrument Meteorological Conditions (IMC)
Weather conditions below the minimums prescribed for visual flight, requiring flight by reference to instruments. Inadvertent flight into IMC by a pilot without an instrument rating is one of the most lethal scenarios in general aviation.
Instrument Rating
An additional rating on a pilot certificate permitting flight under instrument flight rules. 14 CFR 61.65 requires 50 hours of cross-country pilot-in-command time and 40 hours of actual or simulated instrument time, among other items.
J
Jeppesen Chart
A commercially produced aeronautical chart or instrument procedure chart, widely used alongside or instead of the FAA's own publications. The layout differs from FAA charts, and pilots generally standardize on one or the other.
Jet Stream
A narrow band of very strong winds in the upper atmosphere, typically found near the tropopause. It matters to light aircraft mainly through its influence on weather systems rather than as a direct wind at training altitudes.
K
KIAS
Knots indicated airspeed, the reading on the airspeed indicator expressed in knots. Related abbreviations are KCAS for calibrated airspeed, which corrects for instrument and position error, and KTAS for true airspeed.
Knot
One nautical mile per hour, the standard unit of speed in aviation. A nautical mile is about 1.15 statute miles, so 100 knots is roughly 115 miles per hour.
L
Landing Gear
The wheels, struts and brakes that support the aircraft on the ground. Fixed gear stays down permanently; retractable gear folds away in flight and is one of the features that makes an airplane complex under 14 CFR 61.31(e).
Lazy Eight
A commercial pilot maneuver consisting of two opposing 180-degree climbing and descending turns in which pitch, bank and airspeed change continuously. It is widely considered the hardest of the commercial maneuvers to fly smoothly.
Leaning
Adjusting the mixture control to reduce the amount of fuel relative to air as the aircraft climbs and the air becomes less dense. Correct leaning improves fuel economy and engine smoothness and prevents spark plug fouling.
Lift
The aerodynamic force generated by the wing acting perpendicular to the relative airflow, opposing weight in level flight. It depends on airspeed, wing area, air density and angle of attack.
Load Factor
The ratio of the total lift produced to the aircraft's weight, expressed in g. Load factor rises sharply in a steep turn, and the stall speed rises with the square root of the load factor.
Logbook
The record a pilot keeps of flight time, training received and endorsements, required by 14 CFR 61.51 for the time used to meet certificate and currency requirements. It may be paper or electronic.
M
Magnetic Compass
The only direction instrument that needs no power, and the reference against which the heading indicator is set. It has well-known errors in turns and during acceleration and deceleration that are examined on the private pilot written.
Magnetic Variation
The angular difference between true north and magnetic north at a given location, shown on sectional charts as isogonic lines. It must be applied when converting a true course measured on a chart into a magnetic heading to fly.
Magneto
An engine-driven generator that supplies the high-voltage spark to the spark plugs independently of the aircraft's electrical system. Piston aircraft engines have two for redundancy, and both are tested during the run-up before every flight.
Maneuvering Speed
The highest speed at which abrupt full deflection of a single flight control will stall the wing before the structural limit load factor is exceeded. It decreases as the aircraft gets lighter, in proportion to the square root of the weight ratio.
Mean Sea Level (MSL)
Altitude measured from average sea level rather than from the ground beneath the aircraft. Cruising altitudes, airspace boundaries and the altimeter reading are given in feet MSL.
METAR
A routine coded observation of current weather at an airport, issued typically every hour. It reports wind, visibility, present weather, cloud, temperature, dew point and altimeter setting in a fixed order.
Mixture Control
The cockpit control, usually a red knob, that sets the ratio of fuel to air delivered to the engine. Pulling it fully out cuts the fuel supply and is the normal way of shutting the engine down.
Multi-Engine Rating
A class rating added to a pilot certificate authorizing the pilot to act as pilot in command of a multi-engine airplane. There is no minimum hour requirement; it is awarded on proficiency after training that concentrates on engine-out handling.
N
Never Exceed Speed
The maximum speed at which the aircraft may be operated in any condition, marked by the red line on the airspeed indicator. Exceeding it risks structural damage or flutter.
Night Currency
The requirement in 14 CFR 61.57(b) to have made three takeoffs and three landings to a full stop within the preceding 90 days, during the period from one hour after sunset to one hour before sunrise, to carry passengers at night.
Non-Towered Airport
An airport without an operating control tower, where pilots self-announce their position and intentions on a common frequency and separate themselves by standard procedure. Most airports in the United States are non-towered.
NOTAM
A Notice to Air Missions, giving time-critical information about the condition of airports, airspace, navigation aids and hazards. Checking NOTAMs is part of the preflight action required by 14 CFR 91.103.
O
Oral Examination
The ground portion of a practical test, in which the examiner questions the applicant on the knowledge and risk management elements of the Airman Certification Standards. It commonly lasts two to three hours for a private pilot checkride.
Outside Air Temperature (OAT)
The ambient temperature of the air outside the aircraft, used in performance calculations and in assessing the likelihood of icing. It is a required input for working out density altitude and true airspeed.
Oxygen Requirements
The rules in 14 CFR 91.211 governing when supplemental oxygen must be used by the crew and offered to passengers, based on cabin pressure altitude and the duration of the exposure. They apply well below the altitudes most people expect.
P
P-Factor
The yawing tendency produced when the descending propeller blade meets the air at a greater angle of attack than the ascending blade, which happens at high power and high angle of attack. In a typical American single it pulls the nose left during a climb, requiring right rudder.
Pilot In Command (PIC)
The person who has final authority and responsibility for the operation and safety of the flight, as defined in 14 CFR 1.1. 14 CFR 91.3 gives the pilot in command authority to deviate from any rule to the extent required to meet an emergency.
Pilot's Operating Handbook (POH)
The manufacturer's manual for a specific aircraft, containing limitations, emergency and normal procedures, performance data and weight and balance information. The version for your individual airframe is the authority, not a generic copy found online.
PIREP
A pilot report of conditions actually encountered in flight, such as turbulence, icing, cloud tops or ride quality. PIREPs are the only weather information that comes from inside the airspace rather than from the ground or a model.
Pitot Tube
The forward-facing tube that collects ram air pressure for the airspeed indicator. It is checked during the preflight inspection for blockage, and many aircraft have an electric heater to prevent it icing.
Pivotal Altitude
The altitude above the ground at which a line from the pilot's eye through the wingtip appears to pivot on a fixed point on the ground. It equals groundspeed in knots squared divided by 11.3 and governs the eights on pylons maneuver.
Preflight Inspection
The systematic walkaround check of the aircraft before flight, covering fuel quantity and quality, oil, control surfaces, tires, brakes, the propeller, the antennas and the static and pitot sources. It is performed from a written checklist every time.
Pre-Solo Written Examination
The written test administered by the instructor before a student's first solo, required by 14 CFR 61.87. It covers the applicable regulations, the airspace rules for the airport concerned, and the flight characteristics and operating limitations of the aircraft to be flown.
Pressure Altitude
The altitude indicated when the altimeter is set to the standard pressure of 29.92 inches of mercury. It is the starting point for calculating density altitude and for reading most performance charts.
Private Pilot Certificate
The certificate authorizing a pilot to carry passengers and fly for personal and business purposes, but not for compensation or hire. 14 CFR 61.109 sets the 40-hour minimum and 14 CFR 61.113 sets the privileges and limitations.
Q
QNH
The altimeter setting that causes the altimeter to read elevation above mean sea level, used internationally and referred to in the United States simply as the altimeter setting. You will meet the term mainly when reading foreign procedures or flying abroad.
R
Ramp
The paved area where aircraft are parked, loaded, fueled and boarded, also called the apron. Ramp movements are covered by airport rules and, at towered fields, sometimes by ground control.
Rate Of Climb
The vertical speed at which the aircraft is gaining altitude, shown in feet per minute on the vertical speed indicator. Best rate of climb speed gives the most altitude per unit of time, while best angle gives the most altitude per unit of distance.
Rectangular Course
A ground reference maneuver in which the aircraft is flown around a rectangular field at a constant distance and altitude, correcting for wind on each leg. It is a direct rehearsal for flying an accurate traffic pattern.
Restricted ATP (R-ATP)
An Airline Transport Pilot certificate with restricted privileges, issued under 14 CFR 61.160 at 750, 1,000 or 1,250 hours to qualifying military pilots and aviation degree holders rather than the standard 1,500. The minimum age is 21 rather than 23.
Rotate
The action of raising the nose at the appropriate speed during the takeoff roll so that the aircraft lifts off. The rotation speed is published in the Pilot's Operating Handbook for the aircraft and configuration.
Rudder
The hinged control surface on the vertical fin that yaws the nose left and right, operated by the foot pedals. Its main job in normal flight is coordination rather than turning, and on the ground it steers the nosewheel.
Runway Incursion
Any unauthorized presence of an aircraft, vehicle or person on a runway or its protected area. It is one of the FAA's highest-priority safety issues and is the reason hold short lines and clearance readbacks are treated so seriously.
S
Sectional Chart
The primary VFR navigation chart in the United States, at a scale of 1 to 500,000, showing terrain, airspace, airports, obstructions and navigation aids. Southern California is covered by the Los Angeles sectional.
Skid
An uncoordinated turn in which the tail slides outward, shown by the inclinometer ball moving toward the inside of the turn. A skidding turn at low speed and low altitude is the classic entry to a stall and spin.
Slip
An uncoordinated flight condition in which the aircraft moves sideways toward the lower wing. A forward slip is used deliberately to increase the rate of descent without increasing airspeed, and a sideslip is used to keep straight in a crosswind landing.
Slow Flight
Flight at an airspeed just above the stall, used to demonstrate control at high angles of attack and the increased power required to maintain altitude. It is a required maneuver on the private pilot practical test.
Solo
Flight in which the student is the sole occupant of the aircraft. It requires a student pilot certificate, a medical certificate for airplane operations, and instructor endorsements under 14 CFR 61.87 that remain valid for 90 days.
Special VFR
A clearance permitting VFR flight in controlled airspace at an airport in weather below basic VFR minimums, requiring at least one statute mile visibility and the ability to remain clear of cloud. It must be requested from ATC and is not available at every airport.
Squawk
The four-digit code set on the transponder so that ATC radar can identify the aircraft. Code 1200 is the standard VFR code in the United States, and 7500, 7600 and 7700 signify hijacking, lost communication and emergency respectively.
Stall
The loss of lift that occurs when the wing exceeds its critical angle of attack. A stall can happen at any airspeed, in any attitude and at any power setting, which is why angle of attack rather than speed is the correct way to think about it.
Standard Rate Turn
A turn at three degrees per second, which completes a 360-degree turn in two minutes. It is marked on the turn coordinator and is the standard rate used in instrument flying.
Steep Turn
A turn at a bank angle of 45 degrees for the private pilot practical test and 50 degrees for the commercial, flown while holding altitude and airspeed within tight tolerances. It demonstrates control at increased load factor.
Student Pilot Certificate
The FAA certificate required before flying solo, applied for through IACRA under 14 CFR 61.83. The minimum age is 16 for airplanes and 14 for gliders and balloons, and the certificate does not expire.
T
TAF
A Terminal Aerodrome Forecast, a coded forecast of expected weather at a specific airport, normally covering 24 or 30 hours. It uses much of the same coding as a METAR but describes the future rather than the present.
Tailwheel
A landing gear arrangement with two main wheels forward and a small wheel under the tail, also called conventional gear. 14 CFR 61.31(i) requires specific training and a logbook endorsement before acting as pilot in command of a tailwheel airplane.
Temporary Flight Restriction (TFR)
A temporary restriction on flight in a defined area, issued for reasons such as presidential movements, wildfires, sporting events or disaster relief. TFRs appear in NOTAMs and in electronic flight bag apps, and entering one without authorization has serious consequences.
Touch And Go
A landing immediately followed by a takeoff without stopping, used to practice more circuits in a given time. Some currency requirements specify landings to a full stop, so touch and goes do not always count.
Traffic Pattern
The standard rectangular circuit flown around an airport, consisting of upwind, crosswind, downwind, base and final legs. Turns are to the left unless otherwise specified, and the pattern altitude is typically 1,000 feet above the field.
Transponder
The equipment that replies to air traffic control radar with an identifying code and, with Mode C, with the aircraft's pressure altitude. 14 CFR 91.215 sets out where an operating transponder with altitude reporting is required.
Trim
An adjustable tab or mechanism that relieves the control pressure the pilot would otherwise have to hold, allowing the aircraft to maintain an attitude hands-off. Using trim properly is the difference between wrestling an airplane and flying one.
True Airspeed
The aircraft's actual speed through the air mass, equal to calibrated airspeed corrected for air density. True airspeed increases with altitude for a given indicated airspeed, and it is the figure used with wind to calculate groundspeed.
U
Uncontrolled Airspace
Airspace in which air traffic control has no authority over VFR traffic, which in the United States means Class G. Pilots remain responsible for separation by see and avoid, and lower weather minimums apply.
Unicom
A non-government radio frequency at an airport used for advisory information such as runway in use, wind and fuel services. At non-towered fields it often doubles as the common traffic advisory frequency.
Upwind Leg
The leg of the traffic pattern flown parallel to the landing runway in the direction of landing, normally after takeoff or after a go-around. It precedes the crosswind leg in a standard circuit.
Useful Load
The difference between maximum gross weight and empty weight: everything you can put in the aircraft, including fuel, occupants and baggage. In a four-seat trainer with full fuel it is often less than four adults weigh.
V
Vertical Speed Indicator
The instrument displaying the rate of climb or descent in feet per minute. It lags behind the actual change, so it is used to confirm a trend rather than to control the aircraft moment to moment.
Visual Flight Rules (VFR)
The rules governing flight by visual reference to the ground and horizon, with prescribed minimum visibility and distance from cloud that vary by airspace class and altitude. Most private pilot flying is conducted under VFR.
Visual Meteorological Conditions (VMC)
Weather conditions equal to or better than the minimums prescribed for visual flight. The abbreviation is easy to confuse with Vmc, the multi-engine control speed, which is unrelated.
Vmc (Minimum Control Airspeed)
In a multi-engine airplane, the minimum airspeed at which directional control can be maintained with the critical engine inoperative and the remaining engine at takeoff power. It is marked by a red radial line on the airspeed indicator.
VOR
VHF Omnidirectional Range, a ground-based navigation aid transmitting radials that an aircraft receiver can track to or from the station. It predates GPS and is still used, tested and required as a backup in parts of the system.
V-Speeds
The standard set of defined airspeeds for an aircraft, each with a subscript, published in the Pilot's Operating Handbook. They include stall speeds, flap and gear limits, best climb speeds, maneuvering speed and never exceed speed.
Vx
Best angle of climb speed, which gives the greatest altitude gain for a given distance over the ground. It is the speed used to clear an obstacle after takeoff, and it is slower than best rate of climb.
Vy
Best rate of climb speed, which gives the greatest altitude gain for a given time. It is the normal climb speed after the obstacle, if any, has been cleared.
W
Wake Turbulence
The pair of counter-rotating vortices trailing from the wingtips of an aircraft in flight, strongest when it is heavy, slow and clean. Behind a large aircraft the wake can roll a light airplane, which is why ATC applies separation and why pilots stay above and upwind of the preceding aircraft's path.
Weight And Balance
The calculation confirming that the aircraft is within its maximum gross weight and that the center of gravity falls within limits for the whole flight. It is required before flight and is one of the items an examiner will ask you to work through on a checkride.
Wind Correction Angle
The angle between the heading flown and the desired course, applied to compensate for the wind pushing the aircraft sideways. It is the reason your heading and your track are almost never the same number.
Wind Shear
A sudden change in wind speed or direction over a short distance, which can cause abrupt changes in airspeed and lift. It is most dangerous close to the ground on approach and departure, and it is associated with thunderstorms, fronts and terrain.
X
X-Country
The common written shorthand for cross-country flight, seen in logbooks, training records and syllabi. It means the same thing as cross-country and is subject to the same definitions in 14 CFR 61.1.
Y
Yaw
Rotation of the aircraft about its vertical axis, moving the nose left or right, controlled primarily by the rudder. Yaw that is not wanted, produced by aileron drag or by the propeller, is what the rudder is mostly used to cancel.
Yoke
The control wheel or column used to operate the ailerons and elevator, moving fore and aft for pitch and rotating for roll. Some training aircraft, including the Diamond DA20, use a center stick instead.
Z
Zero Fuel Weight
The weight of the aircraft, occupants and baggage without any usable fuel on board. Some aircraft have a maximum zero fuel weight limit, which constrains how much payload can be carried regardless of fuel load.
Zulu Time
Coordinated Universal Time, used throughout aviation so that flights crossing time zones share one clock. Weather reports, forecasts, NOTAMs and flight plans are all in Zulu, and Pacific Daylight Time is Zulu minus seven hours.
How To Actually Learn This Vocabulary
Do not try to memorize a glossary. Vocabulary learned from a list decays within days, and vocabulary learned in context stays for years. Three things work.
Listen to live air traffic control before you ever key the microphone. Twenty minutes of Van Nuys tower on a streaming site, with a sectional chart open beside you, will teach you more about airspace, phraseology and traffic patterns than an hour of reading. You will hear the same twenty phrases repeated, which is exactly the point.
Look terms up immediately after a lesson, not before. Your instructor will use ten words you do not know on every early flight. Write them down on the walk back to the office and look them up that evening while the flight is still fresh. Attached to a memory, they stick.
Read the Pilot's Operating Handbook for the airplane you actually fly. It is the least exciting and most useful document in flight training, and almost every term above appears in it in context, applied to a specific airframe with specific numbers.
Related Reading
- Student pilot resources — the paperwork, the medical and the tests, in the order they happen.
- Airspace classes explained — Class A through G in depth, with the VFR weather minimums.
- Maneuvering speed explained — the formula behind one of the terms above.
- How to fly a plane — the controls and the four forces in plain language.
- The private pilot written exam — where most of this vocabulary is tested.
- VFR versus IFR — the difference between the two sets of rules, explained.
- Site map — every page on this site if you would rather scan than search.
Aviation Terminology FAQ
How Many Aviation Terms Does A Student Pilot Need To Know?
There is no fixed number, but the working vocabulary for a private pilot certificate is a few hundred terms, of which the 150 on this page are the ones that come up most often in training, on the written exam and on the oral.
What Does VFR Mean?
Visual Flight Rules: the rules for flying by visual reference to the ground and horizon, with minimum visibility and cloud clearance requirements that vary by airspace class and altitude. Most private pilot flying is VFR.
What Is The Difference Between AGL And MSL?
AGL is height above the ground directly beneath the aircraft; MSL is altitude above mean sea level. Your altimeter reads MSL, traffic pattern altitudes are usually quoted AGL, and confusing the two near terrain is dangerous.
What Does Squawk Mean In Aviation?
It means to set a specific four-digit code on the transponder so that air traffic control radar can identify your aircraft. Code 1200 is the standard VFR code in the United States.
What Is A Knot And Why Do Pilots Use It?
A knot is one nautical mile per hour. Aviation uses nautical miles because a nautical mile corresponds to one minute of latitude, which makes distance measurement on a chart straightforward.
What Does Zulu Time Mean?
Coordinated Universal Time, used across aviation so that everyone works from a single clock regardless of time zone. Weather reports, forecasts and flight plans are all in Zulu; Pacific Daylight Time is Zulu minus seven hours.
What Is The Difference Between VMC And Vmc?
Visual Meteorological Conditions are weather conditions good enough for visual flight. Vmc, written with a lower-case subscript, is the minimum control airspeed of a multi-engine airplane with one engine inoperative. They are unrelated and both are examined.
Do I Need To Learn Aviation Terminology Before My First Lesson?
No. Nothing needs to be studied before a first flight. Your instructor will explain each term as it comes up, and looking words up afterwards, attached to a memory of the flight, is far more effective than memorizing a list in advance.
Learn The Words In The Airplane
Every term on this page makes more sense after an hour in the left seat. A discovery flight is $229 for 60 minutes out of Van Nuys, you fly it yourself with an instructor beside you, and it is logged as dual instruction toward your certificate. If you want to talk through where to start, book a free consultation or call (818) 330-1318. We are at 7900 Balboa Blvd, Van Nuys, CA 91406, open every day from 9 AM to 9 PM.