BR-ANAC-R-VFRH key terms

An official authorisation issued by the civil aviation authority allowing a person to operate remotely piloted aircraft, granted after demonstrating the knowledge and, where required, practical skills defined in the applicable regulation.

The recorded entry of a remotely piloted aircraft in the national register, assigning a unique identification mark that must be displayed on the aircraft and linked to its owner and operational category.

The condition in which the remote pilot maintains direct, unaided visual contact with the aircraft at all times, allowing continuous monitoring of its flight path, position and surrounding traffic or obstacles.

The highest mass at which an aircraft is certified to begin its take-off run or, for rotorcraft, to lift off, including all structure, equipment, payload and fuel or energy storage aboard.

The mass of an aircraft in its basic configuration, including structure, systems and permanently installed equipment, but excluding crew, payload, fuel or energy storage and removable items.

The difference between maximum take-off mass and empty mass, representing the total mass available for occupants, payload, fuel or batteries and any removable equipment carried.

The mass of everything carried aboard that produces revenue or serves the mission, such as cameras, sensors, cargo or dispensable loads, excluding the aircraft structure and energy source.

The point through which the total weight of an aircraft is considered to act; its position must remain within approved limits for the aircraft to be controllable and stable in flight.

The horizontal distance measured from a defined reference datum to the center of gravity of an item or of the whole aircraft, used with mass to compute moments in balance calculations.

The altitude in the standard atmosphere at which the prevailing air density would occur, combining the effects of pressure altitude, temperature and humidity on aircraft and engine performance.

The altitude indicated on an altimeter set to the standard sea-level pressure of 1013.25 hectopascals, used as the basis for computing aircraft and engine performance.

The highest density altitude at which a rotorcraft can still achieve a specified climb rate, beyond which climb performance becomes inadequate for safe operation.

The maximum altitude, in or out of ground effect, at which a rotorcraft can hover while remaining within its approved mass and power limits under the prevailing atmospheric conditions.

The improvement in rotor thrust and reduction in induced power required when a rotorcraft operates close to a surface, caused by restriction of the downwash and altered airflow around the rotor disc.

The additional lift produced by a rotor as horizontal airspeed increases, because the rotor encounters undisturbed air and the induced flow through the disc becomes more efficient.

The airspeed at which the rotor becomes largely independent of its own downwash and out-of-ground-effect performance is achieved, typically reached at a modest forward speed.

The downward velocity imparted to air as it passes through the rotor disc, producing lift but also consuming power; it is largest in the hover and decreases as forward speed increases.

The unequal lift generated on the advancing and retreating sides of a rotor disc in forward flight, caused by differing relative airflow velocities, which is balanced mainly by blade flapping and cyclic feathering.

The up-and-down movement of a rotor blade about its flapping hinge or flexible element, which equalises lift across the disc and relieves bending loads at the hub.

Loss of lift on the retreating side of the rotor disc when high forward speed or high load causes the blade to exceed its critical angle of attack, producing vibration and pitch-up.

A rotorcraft flight condition in which the rotor is driven by upward airflow through the disc rather than by engine power, allowing a controlled descent and landing after power loss.

A hazardous descent condition in which the rotor descends into its own recirculating downwash, causing loss of lift, vibration and reduced control effectiveness, typically during steep powered descents.

Uncommanded horizontal movement of a rotorcraft caused by tail rotor thrust or other asymmetric forces, which must be corrected by cyclic input or compensated by design.

The principle requiring a pilot to remain alert and scan for other aircraft, and to manoeuvre as necessary to avoid collision, regardless of whether traffic information is available.

The regulatory priority rules determining which aircraft must give way in converging or overtaking situations, for example giving way to aircraft on the right or to landing aircraft.

Airspace of defined dimensions within which air traffic control service is provided to flights under instrument or visual flight rules, and where entry may require prior clearance.

A system of lettered classes defining the services provided, the clearance requirements and the operating rules that apply within each volume of airspace.

The pressure value entered into an altimeter so that it indicates altitude relative to a chosen reference, such as mean sea level or a defined transition level.

A change in wind speed or direction over a short distance, vertically or horizontally, which can abruptly alter lift and airspeed and is hazardous at low altitude.

A localized, intense downdraft that spreads out on reaching the surface, producing strong diverging winds and rapid performance loss, especially dangerous during take-off and landing.

A condition in which body tissues receive insufficient oxygen, causing impaired judgement, coordination and vision that can develop without the person noticing the deterioration.

Abnormally rapid or deep breathing that lowers carbon dioxide in the blood, producing dizziness, tingling and confusion that can mimic the effects of hypoxia.

A mistaken perception of the aircraft's position or motion relative to the earth, arising when visual cues are lost and the senses give misleading information to the pilot.

The pilot's continuous understanding of the aircraft, its environment, other traffic and the mission state, enabling timely decisions and avoidance of hazards.

The standardised words and sentence patterns used in voice communications to ensure clear, unambiguous and predictable exchanges between pilots and air traffic services.

The procedure in which a pilot repeats back received instructions or clearances so that the issuing controller can verify they were correctly understood and accepted.

The international radiotelephony distress signal, spoken three times, used to declare that an aircraft is in grave and imminent danger and requires immediate assistance.

A method of determining position by advancing a known starting point using recorded heading, speed and elapsed time, with allowances for wind and system drift.

The speed of an aircraft relative to the surface of the earth, resulting from the combination of its airspeed and the effect of the prevailing wind.

The angular difference at a given location between true north and magnetic north, applied when converting between true and magnetic directions for navigation and heading references.