BR-ANAC-PCA-IFR key terms

The set of rules governing flight in instrument meteorological conditions, or in visual conditions when the pilot elects to operate under them, requiring instrument qualification, IFR-certified equipment, and ATS clearance.

Weather conditions expressed in terms of visibility, distance from cloud, and ceiling that are below the minimums prescribed for flight under visual flight rules, requiring instrument procedures and qualifications.

An authorization from air traffic control for an aircraft to proceed under specified traffic conditions within controlled airspace, normally containing identification, limit, route, altitude, and any required instructions.

The obligation of a pilot to repeat back safety-related clearance elements such as route, altitude, speed, and runway so the controller can verify the instruction was received and understood correctly.

A published ATS procedure linking an aerodrome to a significant point on the en-route structure, providing obstacle clearance and simplifying clearance delivery, often with coded designators and transition routes.

A published ATS procedure connecting an en-route significant point to a point from which an instrument approach can be started, reducing phraseology and providing guaranteed obstacle clearance along the route.

A series of predetermined manoeuvres with published obstacle clearance, used to bring an aircraft from the initial approach fix to a point where a landing can be made, or to a missed approach point.

A specified altitude or height in a precision or approach-with-vertical-guidance procedure at which a missed approach must be initiated if the required visual reference to continue has not been established.

A specified altitude or height in a non-precision approach below which descent must not be made unless the required visual reference for landing has been established and maintained.

A published sequence of manoeuvres to be flown when an approach cannot be completed, guiding the aircraft away from obstacles and back to a holding fix or alternate routing.

A predetermined manoeuvre keeping an aircraft within a specified airspace while awaiting further clearance, defined by a fix, inbound course, turn direction, leg length or time, and limiting altitudes.

The lowest published altitude at which a holding pattern may be flown while maintaining the required obstacle clearance and, where applicable, radio reception for the associated navigation aid.

The lowest altitude providing at least the prescribed obstacle clearance within a sector of a circle, usually 25 nautical miles, centred on a navigation aid or aerodrome reference point.

The lowest published altitude along an airway or route that meets obstacle clearance requirements and, where required, guarantees navigation signal coverage for the whole segment.

The magnetic bearing from a VOR station to an aircraft, displayed by the course deviation indicator; tracking a radial inbound or outbound is a fundamental en-route IFR navigation technique.

A radio navigation aid that measures slant range between aircraft and ground station by timing pulse exchanges, commonly paired with VOR or ILS to provide distance fixes and approach aids.

A precision approach system providing lateral guidance from a localizer and vertical guidance from a glide path, with marker beacons or DME supporting range information and category-based landing minima.

A method of navigation permitting aircraft operation on any desired flight path within the coverage of ground or space-based aids, or within the limits of self-contained aids, or a combination of these.

A navigation specification stating the navigation performance accuracy needed for operation along a route or in an airspace, with on-board performance monitoring and alerting required for RNP operations.

A predetermined geographical position used for route definition or progress reporting, defined by coordinates in RNAV systems or by reference to navigation aids in conventional route structures.

A report made to air traffic services giving aircraft identification, position, time, altitude, and next position with estimated time, used where surveillance coverage is absent or as required by procedures.

The weather minima an aerodrome must satisfy to be nominated as a destination alternate, depending on approach type available and whether the alternate is used at or after the estimated time of arrival.

The fuel required beyond trip fuel to cover contingencies, alternate diversion, final reserve, and any additional fuel mandated by the operator or authority for the planned IFR flight.

The point along a route beyond which an aircraft cannot return to its departure aerodrome with the fuel remaining, requiring careful computation of fuel, wind, and alternate availability.

A point on the route where the time to reach two nominated diversion aerodromes is equal, used with wind and fuel data to select the most efficient diversion option in flight.

The altimeter subscale setting that, when applied on the ground at aerodrome elevation, indicates aerodrome elevation; used below the transition altitude to obtain altitude above mean sea level.

The altitude at or below which the vertical position of an aircraft is controlled by reference to altitudes on the altimeter subscale set to local pressure, above which standard pressure is used.

The standard altimeter setting of 1013.25 hectopascals used at and above the transition level, giving flight levels that ensure common vertical reference between aircraft in the upper airspace.

A surface of constant atmospheric pressure related to the standard datum of 1013.25 hectopascals, expressed in hundreds of feet and used for vertical separation above the transition altitude.

A weather warning issued for hazardous conditions such as severe turbulence, severe icing, volcanic ash, or tropical cyclones that may affect the safety of aircraft in flight over a defined area.

A weather advisory issued for conditions less severe than those in a SIGMET but potentially hazardous, such as moderate turbulence, moderate icing, or extensive mountain obscuration.

A change in wind speed or direction over a short distance, including microbursts and frontal shear, that can cause sudden airspeed and lift changes close to the ground and on approach.

A pilot's mistaken perception of aircraft attitude or motion, often caused by conflicting vestibular and visual cues in low visibility, leading to inappropriate control inputs unless instruments are trusted.

A false sensation of pitch caused by linear acceleration or deceleration, such as feeling a nose-up attitude during take-off acceleration, which can prompt an incorrect and dangerous control correction.

The disciplined, systematic pattern of eye movements and attention allocation across flight instruments used to detect and correct deviations without fixation or omission, especially during high workload.

Training and practices that develop effective use of all available resources, including crew members, automation, and information, to improve safety, decision-making, and coordination in flight operations.

The crew's continuous understanding of which automation modes are active, armed, or disengaged, preventing unintended flight path changes and loss of control when automation behaves unexpectedly.

A rapid descent, often initiated for depressurisation or fire, requiring prompt turn away from the cleared route, use of oxygen and transponder codes, and broadcast of intentions to ATS.

A four-digit SSR code selected to signal distress or urgency, such as 7700 for emergency and 7600 for radio failure, alerting controllers to the nature of the problem.

The published sequence of actions and route, level, and timing rules to be followed when two-way communication is lost, allowing ATS to predict the aircraft's position and protect other traffic.