Glossary of gyroplane terms

How it flies

Lift

The force a wing produces as air flows over and under it, acting roughly perpendicular to the oncoming air and holding the airplane up against its weight. It grows with airspeed and with angle of attack, right up to the angle where the wing stalls.

Relative wind also Relative airflow

The airflow meeting the wing, described from the wing's point of view. It runs exactly opposite to the flight path, so it follows where the airplane is actually going rather than where the nose happens to be pointing.

Angle of attack also AOA, alpha

The angle between the wing's chord line, the straight line from its leading edge to its trailing edge, and the relative wind. It is set by where the wing is going compared with where it is pointed, which is not the same thing as the airplane's attitude against the horizon.

Critical angle of attack also Stalling angle

The angle of attack past which the wing stops flying. It is a fixed property of the wing and does not move with airspeed, weight, bank or power, which is the reason a wing can be stalled at any speed and in any attitude.

Stall also Aerodynamic stall

The loss of lift that follows when the wing exceeds its critical angle of attack and the airflow separates from the upper surface. It is an aerodynamic event, not an engine one: the engine goes on running throughout.

Spin

A stall in which one wing is more deeply stalled than the other, so the airplane descends in a corkscrew while it rotates. It is a different condition from a spiral dive, where the wings are still flying and the airspeed climbs quickly.

Load factor also G-load, Gs

The ratio of the load the wings are carrying to the actual weight of the airplane, expressed in Gs. It rises in a turn and in any abrupt pull-up, and because stalling speed rises with it, a loaded wing stalls at a higher airspeed than the same wing in level flight.

Adverse yaw

The tendency of an airplane to yaw away from the direction it is rolling. The aileron that deflects down makes more lift and more drag than the one that deflects up, and that extra drag drags the nose toward the outside of the turn. Rudder is what offsets it.

P-factor also Asymmetric propeller loading

One of the left-turning tendencies of a single engine airplane whose propeller turns clockwise seen from the cockpit. At a high angle of attack the descending blade meets the air at a greater angle than the ascending blade, makes more thrust on that side, and yaws the nose.

Ground effect

The drop in induced drag that occurs while an airplane is within roughly a wingspan of the surface, because the ground interferes with the wingtip vortices and the downwash behind the wing. It is why an airplane can feel as though it wants to float just above the runway, and why it can leave the ground before it has the speed to climb away.

Best glide speed also Best glide

The airspeed that covers the most ground for the altitude lost with the engine producing no thrust. The figure belongs to the individual airplane and shifts with weight, so the only correct source for it is that aircraft's flight manual.

Slip

Flight in which the airplane is moving partly sideways toward its low wing, with the nose off to one side of the direction of travel. In a turn it means the rate of turn is too low for the bank being held, and the inclinometer ball rests toward the inside of the turn.

Skid

Flight in which the airplane slides toward the outside of a turn, because the rate of turn is too great for the bank being held. The inclinometer ball rests toward the outside. A skidding turn low to the ground is the classic setup for a stall that drops into a spin.

The aircraft

High wing and low wing

Where the wing joins the fuselage, above the cabin or below it. A high wing gives a clearer view downward and shade on the ramp; a low wing gives a clearer view through a turn and puts the fuel tanks below the cabin. Both layouts are ordinary trainers and neither is the harder one to learn in.

Tricycle gear also Nosewheel gear

Landing gear with the third wheel at the nose, ahead of the two main wheels. The center of gravity sits ahead of the mains, so the airplane naturally tracks straight along the ground, which is why nearly every modern trainer is built this way.

Conventional gear also Tailwheel, taildragger

Landing gear with the third wheel at the tail, behind the two main wheels. The center of gravity sits behind the mains, which makes the airplane directionally unstable on the ground and demands attention through the whole rollout. A separate instructor endorsement is required before acting as pilot in command of one.

Complex airplane

An airplane with retractable landing gear, flaps and a controllable pitch propeller. Flying one as pilot in command calls for a one-time instructor endorsement, which is not a certificate and not a rating.

High performance airplane

An airplane with an engine above the horsepower threshold written into the federal regulations. Like a complex airplane it needs its own one-time instructor endorsement, and the two categories are independent: an airplane can be one, the other, both or neither.

Fixed pitch propeller

A propeller whose blade angle is set when it is manufactured and cannot be altered in flight. The airplane has a single engine control lever, the throttle, and the propeller speed rises and falls with power and airspeed together.

Constant speed propeller also Controllable pitch propeller

A propeller whose blade angle changes automatically to hold whatever engine speed the pilot selects. It adds a second lever alongside the throttle, the propeller control, and it lets the engine make efficient power across a much wider band of airspeeds.

Magneto also Mags

An engine-driven generator that produces the spark for the ignition without drawing anything from the airplane's electrical system. A piston airplane engine carries two of them, each firing its own set of plugs, so the engine keeps running if one fails or the battery goes flat.

Carburetor also Carb

The device that mixes fuel into the incoming air before it reaches the cylinders, using the pressure drop through a venturi to draw the fuel in. That same pressure drop cools the air sharply, which is how a carbureted engine can build induction ice on a warm day.

Mixture also Mixture control

The cockpit control that sets the proportion of fuel to air reaching the engine. Air thins as altitude increases while the fuel flow does not change on its own, so the mixture is adjusted to match. The settings for any given airplane come from its flight manual.

Pitot-static system also Pitot tube, static port

The plumbing that feeds the airspeed indicator, the altimeter and the vertical speed indicator. The pitot tube faces forward and senses the pressure of air brought to a stop against it; the static ports sit flush with the skin and sense the undisturbed ambient pressure. A blockage in either one makes those instruments lie.

Rules and paperwork

Pilot certificate also Pilot license

The document the FAA issues showing what kind of flying a person is qualified to do, from student pilot up to airline transport pilot. Americans say license in conversation, but certificate is the word the regulations use, and the document itself carries no expiry date.

Rating

An addition to a certificate naming what the holder may fly or the conditions they may fly in, such as airplane single engine land, or an instrument rating. A rating is earned through training and a practical test, and it is printed on the certificate.

Endorsement also Instructor endorsement

A signed and dated entry an instructor makes in a pilot's logbook approving them for something specific: solo flight, a knowledge test, a cross country, a particular kind of airplane. It lives in the logbook rather than on the certificate.

Third class medical certificate also Third class medical

The medical certificate a private pilot ordinarily flies on, issued by an aviation medical examiner designated by the FAA after an in-person examination. How long it stays valid depends on the holder's age at the time of the exam, and the current durations are published by the FAA.

BasicMed

An alternative to holding a current FAA medical certificate. The pilot completes a physical exam with any state-licensed physician and an online medical course, then flies within published limits on aircraft size, passengers, altitude and speed. It is open only to pilots who have held an FAA medical certificate before, and it does not cover every kind of flying.

Flight review also Biennial flight review, BFR

A session with a flight instructor, part on the ground and part in the air, that a certificated pilot must complete every 24 calendar months in order to keep acting as pilot in command. There is no pass or fail: the instructor signs the logbook once the review is complete.

Currency

Having flown recently enough to satisfy a particular recent-experience rule. The one private pilots meet first is that carrying passengers requires three takeoffs and landings within the preceding 90 days in the same category and class of aircraft. Being current is not the same as being proficient, and neither is the same as the flight review.

Part 61

Training conducted directly against the part of the federal aviation regulations that lists what every pilot must learn and demonstrate. There is no FAA-approved syllabus to follow, so the instructor sets the order and the schedule bends around the student. Most independent instructors and small flight schools work this way.

Part 141

Training at a school that holds an FAA-approved training course outline, which it must teach in sequence and which the FAA inspects. The structure suits full-time and career-track students, and an approved course can require fewer total flight hours than the same certificate earned outside one.

Airman Certification Standards also ACS

The FAA document listing every task, knowledge item and risk-management item a practical test can cover for a given certificate or rating, together with the tolerances a maneuver has to be flown within. It tells a candidate what they will be asked before they are asked it, and it replaced the older Practical Test Standards.

Checkride also Practical test

The practical test at the end of training for a certificate or rating: an oral examination followed by a flight, both graded against the Airman Certification Standards. Passing it, along with the written knowledge test, is what earns the certificate.

Designated pilot examiner also DPE, examiner

A private individual the FAA authorizes to give practical tests and issue certificates on its behalf. A DPE is not an FAA employee and charges a fee for the test, normally separate from anything the flight school bills.

Flying it

Traffic pattern also Circuit

The rectangular path aircraft fly around a runway so they arrive in an orderly sequence, made up of the upwind, crosswind, downwind, base and final legs. Turns are to the left unless the airport publishes right traffic for that runway.

Downwind leg also Downwind

The leg of the traffic pattern flown parallel to the runway and off to one side of it, travelling in the opposite direction to the landing. Most pattern radio calls and the pre-landing checks happen along it.

Base leg also Base

The leg of the traffic pattern flown at right angles to the runway, joining the end of downwind to the final approach. It is where the descent is established and where height is judged against remaining distance.

Final approach also Final

The last leg of the traffic pattern, flown straight and in line with the runway toward the landing. Aircraft on final have the right of way over other aircraft in flight and over aircraft operating on the surface.

Go-around also Balked landing

Abandoning an approach and climbing away to fly the pattern again. It is a normal maneuver taught from early in training, not an admission of failure, and it is the standard answer to an approach that is not working out or a runway that is not clear.

Crosswind component

The part of the wind acting across the runway rather than along it, worked out from the wind direction and speed against the runway heading. Every airplane has a demonstrated crosswind figure recorded in its flight manual, and that figure is specific to the type.

Short field operation also Short field takeoff, short field landing

A takeoff or landing technique for a runway with little length to spare, or with an obstacle at the end, aimed at using the least possible ground distance. The limiting factor is the length available, and it is a required task on the private pilot practical test.

Soft field operation also Soft field takeoff, soft field landing

A takeoff or landing technique for grass, dirt, sand or snow, aimed at keeping weight off the nosewheel and getting the wheels out of a yielding surface early. The limiting factor is the surface itself rather than the length available.

Run-up also Engine run-up, run-up area

The engine and systems check carried out before takeoff at a set power setting, in a marked area clear of taxiing traffic. It exercises the magnetos, the propeller control and the carburetor heat or alternate air, so that a fault shows itself on the ground instead of on climb-out.

Hold short also Hold short line

An instruction to stop before a marked line and not cross it, most often at the edge of a runway. Crossing a hold short line without the clearance to do so is a runway incursion, and it is reportable.

Weather and planning

METAR also Aviation routine weather report

A coded observation of the weather at an airport at one moment in time, giving wind, visibility, cloud, temperature, dew point and altimeter setting. It records what is happening, not what is expected.

TAF also Terminal aerodrome forecast

A coded forecast of the weather expected in the area immediately around an airport over a defined period ahead. It is a prediction rather than an observation, and it is issued only for airports that have forecasting service.

Ceiling

The height above the ground of the lowest cloud layer reported as broken or overcast, or the vertical visibility into an obscuration such as fog. Layers reported as few or scattered are not ceilings, however low they sit.

Flight category also MVFR, LIFR

A shorthand for how good or bad conditions are, worked out from the reported ceiling and visibility together. VFR is the best of the four and LIFR the worst, with MVFR meaning marginal. The categories are a briefing aid; the legal minimums for a flight come from the regulations for the airspace being flown in.

Density altitude

Pressure altitude corrected for temperature: the altitude the air feels like to the wing, the propeller and the engine. Heat, humidity and field elevation all push it up, and when it is high the airplane climbs worse and needs more runway than the same airplane on a cold day at sea level.

Dew point also Dewpoint

The temperature to which air must be cooled before the water vapor in it begins to condense. When the reported temperature and dew point sit close together the air is near saturation, and cloud, fog and visible moisture become likely.

Wind shear

A sudden change in wind speed or direction over a short distance, either horizontally or vertically. Because it changes the airspeed the wing sees, it can produce a rapid loss or gain of lift, and it matters most close to the ground where there is no height to trade.

NOTAM also Notice to Air Missions

A short published notice about something temporary a pilot needs to know: a closed runway, an unlit tower, a navigation aid out of service, an airspace restriction. Reviewing the ones relevant to a route is part of preflight planning.

Sectional chart also Sectional

The visual navigation chart used for VFR flying, showing terrain and elevation, obstructions, airports, airspace boundaries and landmarks. Each one covers a named region of the country and is reissued on a published revision cycle.

Pilotage

Navigating by looking outside and matching visible landmarks against a chart. It needs no arithmetic and no radio aid, and it stops working the moment the visibility or the terrain stops offering features worth recognizing.

Dead reckoning

Navigating by calculation: from a known starting point, a heading, an airspeed, the forecast wind and the time flown, the pilot works out where the airplane should now be. In practice it is used alongside pilotage rather than instead of it.

Airspace and radio

Class A airspace

Controlled airspace beginning at 18,000 feet MSL over the United States. Everything flown in it operates under instrument flight rules on an air traffic control clearance, so a pilot flying visually does not enter it at all.

Class B airspace

The controlled airspace surrounding the nation's busiest airports, built in tiers that are often described as an upside-down wedding cake. Entry needs a specific clearance: hearing your call sign is not enough, because the controller has to say you are cleared into the Class B.

Class C airspace

Controlled airspace around a moderately busy airport that has a control tower and radar service. Entry requires two-way radio communication to be established with the approach control facility, meaning the controller has answered using your call sign, but no separate clearance is issued.

Class D airspace

Controlled airspace around an airport that has an operating control tower but no radar service requirement. Entry requires two-way radio communication established with the tower. It generally exists only while the tower is open and reverts to another class of airspace once it closes.

Class E airspace

Controlled airspace that is not Class A, B, C or D. It fills most of the country above a published floor and reaches down to the surface at many airports with instrument approaches. Flying in it under VFR needs no clearance and no radio call, but the cloud and visibility minimums are tighter than in uncontrolled airspace.

Class G airspace also Uncontrolled airspace

Uncontrolled airspace, in which air traffic control provides no separation service to anybody. It sits underneath Class E, usually as a layer near the surface away from airports with instrument approaches. Cloud and visibility minimums still apply, and they vary with altitude and with day or night.

Temporary flight restriction also TFR

A published restriction closing a defined block of airspace for a period, for reasons such as a presidential movement, a wildfire, a large sporting event or a disaster response. It is issued as a NOTAM, and flying into an active one draws consequences ranging from a phone call to certificate action.

Military operations area also MOA

A block of airspace set aside for military training such as formation flying, aerobatics and air combat maneuvering. A civil pilot may legally fly through one whether it is active or not, which is exactly why checking its status and staying alert matters: the traffic inside maneuvers without warning.

Restricted area

Airspace containing hazards to aircraft that are invisible from outside it, such as artillery fire, gunnery or guided missiles. Unlike a military operations area, entering an active one requires permission from the controlling agency, and going in without it is a violation.

ATIS also Automatic Terminal Information Service

A recorded broadcast at a busier airport carrying the current weather, the runway in use and any field conditions, re-recorded as things change and labelled with a letter of the phonetic alphabet. Pilots listen to it before calling the controller and state the letter to show they have it.

CTAF also Common traffic advisory frequency

The radio frequency pilots use to announce their positions and intentions to one another at an airport with no operating control tower. Nobody is controlling traffic on it, so the calls are advisory and separation remains the pilots' own responsibility.

Transponder also Squawk, squawk code, Mode C

A radio unit that replies to air traffic control radar with a four-digit identifying code and, in Mode C, with the aircraft's pressure altitude. The code itself is the squawk, either assigned by a controller or set to the standard VFR code when none has been assigned.

VFR flight following also Radar traffic advisories

A service in which air traffic control watches a VFR flight on radar and calls out traffic that may become a factor. It is requested rather than required, is provided only when controller workload allows, and it never removes the pilot's own duty to see and avoid.

What is deliberately not here

Typical figures. There is no entry giving a usual rotor diameter, cruise speed or empty mass, because those vary by type and an average invented for a glossary is exactly the kind of number this site refuses to publish. Type figures live on the manufacturer pages, sourced individually.

Licence requirements. They differ by country and they change. The training directory lists schools by country; your national civil aviation authority is the only source that counts.

Once you have read a few of these, the knowledge quiz draws questions from them at random. Every answer links back to the term it came from.