Iran CAO PPL Theory key terms

Visual Flight Rules: flight conducted under rules requiring the pilot to remain clear of cloud and maintain visual reference to the ground, with specific visibility and cloud-clearance minima set by the state.

Instrument Flight Rules: flight conducted under rules where navigation and terrain clearance rely on cockpit instruments rather than outside visual reference, requiring an instrument rating and an ATC clearance in controlled airspace.

Airspace of defined dimensions within which air traffic control service is provided to IFR flights and to VFR flights in accordance with the airspace classification, requiring an ATC clearance to enter.

A clearance allowing a VFR flight to operate within a control zone when weather is below normal VFR minima, subject to pilot request, ATC approval, and specified flight-visibility and cloud-clearance conditions.

Controlled airspace extending upwards from the surface around an aerodrome, established to protect approach and departure paths, within which ATC provides aerodrome and approach control services.

An authorization issued by an air traffic control unit for a flight to proceed under specified conditions, including route, level, and any restrictions, which the pilot must read back and comply with.

A four-digit octal code set on the aircraft transponder to identify the flight on secondary surveillance radar, assigned by ATC and read back before the transponder is set.

An airborne secondary surveillance radar unit that replies to ground interrogations, transmitting identification code, pressure altitude, and, in Mode S, aircraft address and selected data.

Secondary Surveillance Radar: a ground system that interrogates aircraft transponders and displays the replies, giving range, bearing, identification, and altitude without relying on skin-paint echoes.

The pilot's repetition of safety-critical elements of an ATC clearance or instruction back to the controller, so the controller can verify the message was received and understood correctly.

The standardized wording and structure of radiotelephony messages defined for aviation use, designed to be unambiguous, brief, and understood across language boundaries.

The international radiotelephony distress signal, spoken three times, used when an aircraft is threatened by serious or imminent danger and requires immediate assistance.

The international radiotelephony urgency signal, spoken three times, used when an aircraft is in an urgent situation but not in immediate danger requiring distress assistance.

A weather warning issued for the safety of all aircraft, concerning the occurrence or expected occurrence of severe turbulence, icing, volcanic ash, tropical cyclone, or other hazardous en-route phenomena.

A routine coded observation of actual weather at an aerodrome, issued at fixed intervals or when conditions change significantly, reporting wind, visibility, weather, cloud, temperature, and pressure.

Terminal Aerodrome Forecast: a coded forecast of expected weather conditions at an aerodrome over a stated period, used for flight planning and alternate selection.

The altimeter subscale setting that, when applied on the ground at an aerodrome, causes the altimeter to indicate the aerodrome elevation above mean sea level.

The altimeter subscale setting that causes the altimeter to read zero on the ground at a specified reference point, so the instrument shows height above that point rather than altitude.

The altitude at or below which the altimeter is set to QNH and above which it is set to standard pressure, as published by the state for a given area.

A surface of constant atmospheric pressure related to a standard datum of 1013.25 hPa and expressed in hundreds of feet, used above the transition altitude to give common height reference.

The angle between the chord line of a wing and the relative airflow approaching it, which primarily determines the lift coefficient and at which the wing stalls.

The angle of attack at which the wing reaches maximum lift coefficient and beyond which airflow separates, causing a stall regardless of airspeed, weight, or attitude.

Drag that results from the generation of lift, caused by the rearward deflection of air and wingtip vortices, decreasing as airspeed increases and increasing with load factor.

The ratio of total lift produced by the aircraft to its weight, expressed in g, which increases in turns and pull-ups and raises the stall speed.

A condition in which airflow separates from the wing because the critical angle of attack is exceeded, producing a loss of lift and often buffet, which is recovered by reducing angle of attack.

The point through which the total weight of the aircraft acts, whose position must remain within a certified forward and aft range for controllability and performance.

The horizontal distance between a mass and the reference datum used for weight-and-balance calculations, multiplied by the mass to give its moment.

A fixed reference point or plane on the aircraft from which all moment arms are measured in weight-and-balance calculations, chosen by the manufacturer and stated in the manual.

The maximum mass at which the aircraft is certified for the start of take-off, limited by structural strength, runway performance, climb performance, and obstacle clearance requirements.

The pressure altitude corrected for non-standard temperature, representing the altitude at which the aircraft would perform in the current air density, affecting take-off, climb, and engine output.

The altitude indicated when the altimeter subscale is set to standard pressure 1013.25 hPa, used as the basis for performance charts and flight levels.

The maximum density altitude at which the aircraft can maintain a specified maximum rate of climb, typically 100 feet per minute for piston-engine aeroplanes.

A condition in which the body tissues receive insufficient oxygen, causing impaired judgement, euphoria, or loss of consciousness, with effects worsening as altitude increases.

The period after loss of adequate oxygen supply during which a person can still take effective corrective action before becoming incapacitated.

Abnormally rapid or deep breathing that lowers blood carbon dioxide, producing dizziness, tingling, and visual disturbance that can mimic hypoxia and must be distinguished from it.

A pilot's incorrect perception of the aircraft's position or motion relative to the earth, often caused by conflicting vestibular and visual cues in low-visibility flight.

The inner-ear organs, including semicircular canals and otoliths, that sense rotation and linear acceleration, and which can generate false sensations during prolonged or complex manoeuvres.

Global Navigation Satellite System: satellite-based positioning providing worldwide three-dimensional position and time, used for en-route navigation and non-precision or augmented approach procedures.

Receiver Autonomous Integrity Monitoring: a receiver function that checks the consistency of satellite signals to detect a faulty satellite and warn the pilot before navigation integrity is lost.

A specified geographical location in space, defined by coordinates or by a navigation aid, used to define an airway, route, or instrument procedure.