MCAA PPL Theory Exam key terms

The maximum speed at which full or abrupt deflection of a single flight control may be applied without overstressing the airframe. It decreases as aircraft mass decreases, so it must be recalculated for the actual take-off or landing mass.

The speed that must never be intentionally exceeded in any flight condition, marked by the red radial line on the airspeed indicator. Exceeding it risks structural failure or flutter, and it is not reduced for turbulence or mass.

The ratio of the lift produced by the aircraft to its weight, expressed in g. In a level turn it rises with bank angle, reaching 2 g at 60 degrees, which raises stall speed and structural stress.

The angle of attack at which the wing can no longer produce increasing lift and airflow separates from the upper surface. It is a fixed value for a given wing, independent of mass, speed, or bank angle.

The acute angle between the wing chord line and the relative airflow approaching it. Lift increases with angle of attack up to the stall, and the angle needed for level flight rises as speed falls.

The rearward component of lift created by the wingtip vortices and downwash behind a wing producing lift. It increases as speed decreases and as mass increases, so it dominates during slow flight and climb.

The certified forward and aft limits within which the aircraft's centre of gravity must remain for all phases of flight. An out-of-limits CG affects stability, control authority, stall recovery, and performance.

The calculation confirming that the aircraft's take-off and landing mass and centre of gravity lie within the certified limits for the planned flight, accounting for crew, fuel, payload, and baggage distribution.

The pressure altitude corrected for non-standard air temperature, representing the altitude at which the aircraft's performance would occur in a standard atmosphere. High values reduce engine power, lift, and propeller efficiency, lengthening take-off runs.

The altitude indicated on an altimeter set to the standard datum of 1013.25 hPa. It is used for flight levels above the transition altitude and as the basis for performance calculations such as density altitude.

The altimeter sub-scale setting that causes the instrument to indicate elevation above mean sea level when the aircraft is on the ground at that location. It is used below the transition altitude for terrain clearance.

The altimeter sub-scale setting that makes the instrument read zero when the aircraft is on the ground at the reference point, so it indicates height above that point rather than altitude above mean sea level.

The altitude, published for each aerodrome or area, at and below which the altimeter is set to QNH and altitude is used. Above it, the standard setting is used and flight levels apply.

A surface of constant pressure shown on the altimeter when the sub-scale is set to 1013.25 hPa, expressed in hundreds of feet, such as FL 75. It provides a common reference for all aircraft above the transition altitude.

The convention assigning flight levels according to magnetic track: tracks from 000 to 179 degrees use odd levels, and tracks from 180 to 359 degrees use even levels, keeping opposing traffic separated by 1000 feet or more.

A level-allocation convention based on magnetic track quadrants, giving different flight levels for 000-089, 090-179, 180-269, and 270-359 degrees. It is used in some states where the semi-circular rule does not apply.

The operating rules under which the pilot keeps the aircraft clear of cloud and in sight of the surface, maintaining specified flight visibility and distance from cloud. A clearance is required to enter controlled airspace.

The minimum flight visibility and cloud separation required for flight under visual flight rules, which vary with airspace class and altitude. Failing to maintain them requires an instrument clearance or a change of route.

An authorisation allowing a flight to operate within a control zone in conditions below the normal VMC minima, subject to an ATC clearance and remaining clear of cloud and in sight of the surface.

Airspace of defined dimensions within which air traffic control service is provided and in which all flights require an ATC clearance. It includes classes A to E, with differing requirements for VFR and IFR traffic.

Controlled airspace extending from the surface up to a specified upper limit around an aerodrome, protecting traffic in the approach and departure paths. Entry normally requires a clearance and radio contact.

The document issued by the state of registry confirming that the aircraft conforms to an approved type design and is safe for flight when maintained in accordance with the applicable requirements. It must be carried on board.

The document recording the aircraft's nationality and registration marks and the identity of its owner. It establishes the state of registry and must be carried on board during flight.

A mandatory instruction issued by the competent authority to correct an unsafe condition found in a type design, requiring inspection, modification, or operational limitation. Compliance is compulsory and is recorded in the aircraft maintenance log.

The certification, signed by an authorised person after maintenance, confirming that the work has been completed satisfactorily and the aircraft is fit for flight within any stated limitations.

The systematic walk-around and checks performed by the pilot before flight to confirm the aircraft's condition, fuel and oil quantities, control freedom, and absence of damage, ice, or obstruction.

Ice formation in the carburettor venturi caused by the temperature drop of accelerating fuel-air mixture, most likely at ambient temperatures between roughly -7 and +21 degrees Celsius with high humidity. It can occur in clear air.

The cockpit control that adjusts the fuel-to-air ratio reaching the engine, leaned as altitude increases to maintain power and economy, and enriched for take-off, climb, and high power settings to control temperatures.

Abnormal, explosive combustion of the fuel-air charge that produces a sharp pressure rise, audible knocking, rising temperatures, and possible engine damage. It is caused by over-lean mixture, high manifold pressure, or low fuel octane.

Ignition of the fuel-air mixture before the spark occurs, usually caused by a hot spot such as a glowing carbon deposit or overheated spark plug. It can quickly damage the engine and is distinct from detonation.

On a multi-engine aeroplane, the engine whose failure produces the most adverse effect on performance and control, determined by the direction of propeller rotation and the resulting asymmetric thrust and drag.

The minimum speed at which the aeroplane remains controllable with the critical engine inoperative, the other at take-off power, and the aircraft trimmed for take-off. Directional control must be maintainable without exceptional skill.

A condition in which the tissues receive insufficient oxygen, causing impaired judgement, euphoria, and loss of consciousness. It can occur from altitude, carbon monoxide, or lung problems, and the pilot may not notice the symptoms.

Over-breathing that lowers blood carbon dioxide, producing dizziness, tingling, and visual disturbance that can mimic hypoxia. It is managed by slowing the breathing rate and, if doubt remains, by using supplemental oxygen.

The period after loss of oxygen supply during which the pilot can still take effective corrective action. It falls rapidly with altitude, from several minutes at 25 000 feet to seconds above 40 000 feet.

A false perception of the aircraft's position or motion caused by misleading vestibular and visual cues, especially when flying without external visual references. The pilot must rely on instruments rather than sensations.

The leading edge of an advancing cold air mass that undercuts warm air, producing a steep frontal surface, rapid cumuliform cloud, showers, and often gusty winds and thunderstorms. It usually passes quickly with a sharp temperature drop.

The boundary along which warm air rides over retreating cold air, giving a gentle slope, layered stratiform cloud, and steady precipitation. It advances slowly and may bring low cloud and reduced visibility after passage.

A narrow band of active thunderstorms or heavy showers, often forming ahead of a fast-moving cold front. It brings severe turbulence, strong wind gusts, and heavy precipitation, and should be avoided by a wide margin.

A line on a weather chart joining points of equal mean sea level pressure. The closer the isobars, the stronger the pressure gradient and the stronger the surface wind, which affects crosswind and turbulence planning.

A change of wind speed or direction over a short distance or time, often near fronts, thunderstorms, or low-level inversions. It can cause sudden airspeed and lift changes close to the ground and is a serious approach hazard.

The angle between true north and magnetic north at a given position, changing slowly with location and time. It converts true headings to magnetic headings and is shown on charts and in the aerodrome data.

The error of a magnetic compass caused by the aircraft's own magnetic fields and electrical equipment. It varies with heading and is recorded on the compass correction card, unlike variation which depends on position.

The direction the aircraft's longitudinal axis points, measured clockwise from true north. It is derived from the planned track and wind correction and converted to magnetic heading before being flown on the compass.

The angle between the aircraft's heading and the track actually made good over the ground, caused by wind. It is corrected by turning into the wind so that the required track is maintained.

A magnetic bearing from a VOR station, identified by the course selector and deviation indicator. Tracking a radial confirms the aircraft's position relative to the station, and the TO/FROM flag shows the direction of flight.

Turbulence generated by wingtip vortices trailing from a heavy aircraft, strongest when it is slow, clean, and heavy. It sinks and drifts with the wind, so departing aircraft should lift off before the preceding aircraft's rotation point.

Any unauthorised presence of an aircraft, vehicle, or person on a protected runway area. It is prevented by accurate readback, sterile cockpit discipline, and thorough lookout before entering or crossing a runway.

The pilot's repetition of a clearance or instruction to ATC to confirm it has been received and understood correctly. Runway-holding, take-off, landing, and route clearances must always be read back.

The four-digit octal code set in the transponder, assigned by ATC for identification and radar separation. Setting the instructed code and confirming it is part of the standard readback and identification procedure.

The international radiotelephony distress signal used when an aircraft is threatened by serious or imminent danger and requires immediate assistance. It is spoken three times, followed by the station identity and the nature of the emergency.

The international radiotelephony urgency signal used for a situation concerning the safety of an aircraft that does not require immediate assistance. It is repeated three times and followed by the station identity and the problem.