KCAA ATPL Theory key terms

The 1944 international treaty that established ICAO and set the basic framework for civil aviation, covering sovereignty, aircraft registration, and the privileges and obligations of contracting states.

A technical document attached to the Chicago Convention containing international standards and recommended practices that contracting states are expected to implement in their national regulations.

Standard and Recommended Practice: an ICAO provision that states should follow; a Standard is binding unless a difference is filed, while a Recommended Practice is desirable but not mandatory.

A document issued by the state of registry confirming that an aircraft type and its individual configuration meet the applicable airworthiness requirements and are safe for flight under stated conditions.

A mandatory notice issued by an airworthiness authority requiring inspection, modification, or operational restriction on aircraft or components to correct an unsafe condition.

Compressed air tapped from a gas turbine compressor and used for cabin pressurization, air conditioning, engine anti-icing, and sometimes starting, depending on the aircraft system design.

A controllable valve that releases cabin air overboard to regulate cabin altitude and rate of change by balancing conditioned bleed-air inflow against the selected pressure schedule.

A set of probes and ports that supplies impact pressure from the pitot tube and static pressure from flush ports to the airspeed indicator, altimeter, and vertical speed indicator.

The tendency of a spinning rotor to respond to an applied force as though it acted ninety degrees later in the direction of rotation, a behavior used in attitude and heading instruments.

Maximum take-off mass: the highest mass at which the aircraft may begin the take-off run, limited by structural strength, runway performance, climb performance, and certification rules.

The mass of an aircraft with structure, powerplant, fixed equipment, unusable fuel, and full operating fluids, excluding crew, passengers, payload, and usable fuel.

The length of the take-off run available plus any clearway, representing the maximum distance declared for completing the take-off and reaching screen height.

Fuel carried to cover unforeseen factors such as weather, routing changes, or air traffic delays; its amount is set by operator policy and applicable regulations, not by normal trip burn.

A condition in which body tissues receive insufficient oxygen, causing impaired judgment, euphoria, headache, and eventually loss of consciousness; altitude exposure is a common cause in aviation.

Excessive breathing that lowers blood carbon dioxide, producing dizziness, tingling, and confusion that can resemble hypoxia; conscious control of breathing rate is the usual corrective action.

A mismatch between actual aircraft motion and the pilot's perceived orientation, often caused by vestibular illusions in low-visibility conditions, leading to incorrect control inputs unless instruments are trusted.

Training and practices that help flight crew use all available resources, including communication, leadership, teamwork, and decision-making, to manage threats and errors safely.

A pilot's accurate understanding of what is happening in and around the aircraft, including position, traffic, weather, systems, and crew intentions, which supports timely and effective decisions.

The altimeter setting that makes a barometric altimeter indicate elevation above mean sea level when the aircraft is on the ground at the reporting station.

The altimeter setting that makes a barometric altimeter read height above a specific reference point, usually the aerodrome elevation, rather than altitude above mean sea level.

International Standard Atmosphere: a defined model of temperature, pressure, and density with sea-level values of 15°C and 1013.25 hPa, used for performance and altimetry calculations.

The boundary between the troposphere and stratosphere where temperature normally stops decreasing with height; its altitude varies with latitude and season and affects jet-stream location.

A narrow band of strong, often westerly upper-level winds near the tropopause, associated with large temperature gradients and capable of significantly affecting flight time and fuel consumption.

A change in wind speed or direction over a short distance, especially hazardous at low altitude during take-off and landing because it can cause sudden airspeed and lift changes.

The largest circle that can be drawn on a sphere, formed by a plane through the center; the shorter arc between two points gives the shortest surface route.

A line that crosses every meridian at the same true angle, appearing straight on a Mercator chart but generally longer than the great-circle route between the same points.

The angular difference at a given place between true north and magnetic north, expressed east or west and applied when converting between true and magnetic directions.

A magnetic bearing from a VOR station, identified by the number and direction shown on the course deviation indicator when the aircraft is on that line.

The vertical guidance component of an instrument landing system, normally providing a 3-degree descent path to the runway, displayed on the glideslope needle or flight director.

Minimum Equipment List: an approved document that allows dispatch with specified equipment inoperative, subject to stated conditions, maintenance actions, and operational limitations.

A rule that prohibits non-essential conversation and activity during critical phases such as taxi, take-off, approach, and landing to keep crew attention on flying and monitoring.

A rapid but controlled descent, often to a lower safe altitude, carried out after cabin depressurization or other emergency, using prescribed speeds, turn directions, and oxygen procedures.

The angle between the wing chord line and the relative airflow, which directly determines lift coefficient and changes with pitch attitude and flight path.

The angle of attack at which airflow separates from the wing and lift begins to decrease sharply, causing a stall regardless of airspeed, weight, or aircraft attitude.

Drag created as a by-product of lift, caused by wingtip vortices and pressure differences; it increases with angle of attack and is greatest at low speed.

The ratio of total lift to aircraft weight, often expressed in g; it increases in turns and manoeuvres and raises stall speed and structural loading.

A four-digit octal code set on the aircraft transponder to identify the flight on secondary surveillance radar, assigned by air traffic control or prescribed for a specific contingency.

The mandatory repetition of safety-related air traffic control instructions, such as clearances and runway assignments, to confirm that the crew has received and understood them correctly.

The international radiotelephony distress call indicating imminent danger and a request for immediate assistance; it has absolute priority over all other communications.

The international radiotelephony urgency call used when a situation is serious but not immediately life-threatening, requesting assistance or priority without declaring a distress condition.