MCAA CPL Theory Exam key terms

Weather conditions in which visibility and distance from cloud meet or exceed the minimum values prescribed for the airspace and altitude being flown, allowing the pilot to navigate and avoid traffic by visual reference.

Conditions in which visibility or cloud distance falls below the VMC minima, so the flight must be conducted under instrument flight rules and the pilot may not rely on outside visual reference for separation or terrain avoidance.

A flight conducted under visual flight rules, in which the pilot maintains separation from other traffic and terrain by visual reference outside the cockpit, subject to prescribed visibility and cloud clearance minima.

A flight conducted under instrument flight rules, where separation is normally provided by air traffic control and the pilot navigates by reference to instruments, following published procedures and clearances.

An authorisation allowing a flight to operate within a control zone in conditions below normal VMC minima, provided the pilot remains clear of cloud and in sight of the surface, with ATC separation applied against IFR traffic.

Controlled airspace extending upwards from the surface to a specified upper limit, established around an aerodrome to protect approach and departure paths, within which ATC clearance is required before entry.

An authorisation issued by an air traffic controller for a flight to proceed under specified conditions, which the pilot must read back where required and comply with unless an amended clearance is obtained.

The mandatory repetition to the controller of safety-related clearance elements such as route, level, heading, speed, frequency and runway, so the controller can verify the instruction was correctly received.

The prescribed set of words and sentence patterns defined for radiotelephony, used to convey clearances and information unambiguously and to reduce the risk of misunderstanding between pilots and controllers.

A receiver circuit that mutes audio output unless a signal above a set threshold is present, suppressing background noise during silence but potentially masking very weak transmissions.

The international aeronautical distress and emergency frequency, monitored by many ATC units and search and rescue services, used to declare an emergency or to attract attention when normal communication fails.

The SSR code selected to indicate a general emergency, alerting controllers that the aircraft requires immediate assistance and priority handling.

The SSR code selected to indicate loss of radio communication, prompting controllers to apply established procedures for radio failure and to separate the aircraft accordingly.

The SSR code selected to indicate unlawful interference with the aircraft, such as hijacking, which alerts controllers and triggers security procedures without requiring a voice transmission.

The angle between the chord line of a wing and the relative airflow approaching it; increasing it raises lift up to the critical value, beyond which the airflow separates and the wing stalls.

The angle of attack at which the wing reaches maximum lift coefficient and beyond which it stalls; it is essentially constant for a given configuration regardless of weight, speed or bank angle.

Drag created as a by-product of lift, caused by the spanwise flow and wingtip vortices that deflect air downward; it increases with angle of attack and decreases as speed rises.

The reduction in induced drag and downwash that occurs when a wing operates within roughly one wingspan of the surface, allowing the aircraft to lift off or float during landing at lower speed.

The ratio of total lift produced to the aircraft's weight, expressed in g; it increases in turns and manoeuvres, raising the stall speed and the structural stress on the airframe.

The maximum speed at which the aircraft may be operated in any condition, marked by a red radial line; exceeding it risks structural damage or loss of control from flutter or excessive loads.

The upper limit of the normal operating speed range, marked by the top of the green arc; above it, flight is permitted only in smooth air and with caution to avoid overstressing the structure.

The speed above which full deflection of a single flight control could produce loads exceeding the design limit; below it, the aircraft stalls before the structure is overstressed.

Pressure altitude corrected for non-standard temperature, representing the altitude the aircraft 'feels' aerodynamically; high values reduce engine power, propeller thrust, lift and climb performance.

The altitude indicated on an altimeter set to the standard pressure datum of 1013.25 hPa, used above the transition altitude and for performance calculations independent of local weather.

The altitude at or below which the aircraft operates on the local altimeter setting and above which it flies on standard pressure, with the changeover made during climb or descent as prescribed.

The pressure value set on the subscale so that the altimeter reads aerodrome elevation when on the ground, giving altitude above mean sea level in the vicinity of the setting's source.

The horizontal distance required from the start of the take-off roll to reaching a specified height above the runway surface, affected by weight, density altitude, wind, slope and runway condition.

The point through which the total weight of the aircraft acts; its position within the permitted range affects stability, control effectiveness, stall speed and take-off and landing performance.

A condition in which the tissues receive insufficient oxygen, causing impaired judgement, euphoria or headache; it develops insidiously with altitude and is a major risk in unpressurised flight.

The period after exposure to a given altitude during which a person can still perform useful, deliberate actions before incapacitation from oxygen deprivation occurs.

Over-breathing that lowers blood carbon dioxide, producing dizziness, tingling and visual disturbance that can mimic hypoxia; treatment is to slow the breathing rate and, if in doubt, use oxygen.

A false perception of the aircraft's attitude or motion, typically when outside visual reference, caused by misleading vestibular and somatosensory cues; the remedy is to trust and interpret the flight instruments.

A false sensation of pitch or bank produced by the otolith organs during sustained acceleration or deceleration, such as the impression of climbing after a rapid acceleration or of banking in a coordinated turn.

Ice formation in the carburettor venturi caused by fuel vaporisation and pressure drop cooling, most likely at moderate temperatures with high humidity; it causes gradual power loss that carburettor heat can clear.

Abnormally rapid, uncontrolled combustion of the fuel-air charge that produces high cylinder pressures, overheating and possible engine damage; it is associated with high power, weak mixture and high intake temperatures.

The cockpit control that adjusts the fuel-to-air ratio delivered to the engine, leaned as altitude increases and enriched for high power or hot conditions to protect the engine from overheating or detonation.

A magnetic bearing from a VOR station, displayed by the course deviation indicator; tracking a radial requires the selected course to match the desired outbound or inbound direction.

The instrument display showing left or right deviation from a selected course, with full-scale deflection representing a fixed angular or lateral tolerance that widens with distance from the station.

The vertical guidance component of an instrument landing system, normally set at a three-degree descent angle and received on a designated UHF frequency, providing obstacle clearance to a decision height.

A published series of predetermined manoeuvres with defined altitudes, courses and minima that allows an aircraft to descend from the en-route structure to a point from which a landing can be made.