MCAA ATPL Theory Exam key terms

The decision speed: the maximum speed at which a pilot may reject a takeoff and stop within the runway, and the minimum speed at which, after a critical engine failure, the takeoff can be safely continued.

Maximum takeoff mass: the highest mass at which the aircraft is certified to begin the takeoff roll, limited by structural strength, performance, or runway and obstacle requirements.

In a multi-engine aeroplane, the engine whose failure produces the most adverse effect on performance and handling, usually because of asymmetric thrust and the resulting yaw.

The narrow speed band at high altitude between the low-speed stall margin (or buffet onset) and the high-speed Mach buffet, where small speed changes can cause loss of control.

The altitude at which an aircraft's maximum rate of climb falls to 100 feet per minute in the relevant configuration, used to define upper operating limits.

The angle between the wing's chord line and the relative airflow, which directly controls lift coefficient and determines the stalling angle.

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

The upward angle of the wings from root to tip when viewed from the front, which provides lateral stability by creating a restoring rolling moment after a sideslip.

The free-stream Mach number at which airflow somewhere on the airframe first reaches Mach 1, producing shock waves and the onset of Mach buffet.

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

International Standard Atmosphere: a defined model with sea-level temperature 15 °C, pressure 1013.25 hPa and a standard lapse rate, used to compare aircraft performance.

The altimeter setting that makes a pressure altimeter read aerodrome elevation when on the ground, giving height above mean sea level in the standard atmosphere.

The altimeter setting that makes the altimeter read zero on the aerodrome, so the instrument indicates height above the aerodrome reference point.

The altitude, published for each aerodrome, above which pilots set standard pressure 1013.25 hPa and express altitude in flight levels.

Reduced Vertical Separation Minimum: an airspace and approval regime permitting 1,000 ft vertical separation between suitably equipped aircraft above a specified flight level, usually FL290.

A notice distributed to flight crews containing time-critical information about hazards, changes, or restrictions at an aerodrome or in airspace that affect flight safety.

A routine coded weather report for an aerodrome giving wind, visibility, runway visual range, present weather, cloud, temperature, and pressure at a stated time.

A coded warning of significant meteorological conditions such as severe turbulence, icing, thunderstorms, or volcanic ash that may affect the safety of flights in a defined area.

Traffic Alert and Collision Avoidance System: airborne equipment that interrogates nearby transponders, displays traffic, and issues traffic advisories and resolution advisories to prevent collisions.

Enhanced Ground Proximity Warning System: equipment using a terrain database and aircraft position to give timely aural and visual warnings of impending controlled flight into terrain.

The vertical guidance beam of an instrument landing system, normally set at about 3 degrees, which the aircraft follows down to decision height for a precision approach.

The magnetic bearing from a VOR station to the aircraft, expressed in degrees; the aircraft's course along a chosen radial is flown by tracking the needle.

The shortest path between two points on the surface of a sphere, whose plane passes through the Earth's centre; used for long-distance navigation.

The angular difference between true north and magnetic north at a given location, easterly or westerly, used to convert between true and magnetic directions.

The angle between the aircraft's heading and its actual track over the ground, caused by wind, which must be corrected by applying a wind correction angle.

A shortage of oxygen reaching body tissues, causing impaired judgment, vision, and coordination; in aviation it can result from high altitude without oxygen or from decompression.

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

G-force induced loss of consciousness, in which high sustained acceleration reduces blood flow to the brain, causing incapacitation that may be preceded by greyout or blackout.

Crew Resource Management: the effective use of all available resources-human, technical, and informational-by flight crew to ensure safe and efficient flight operations.

The pressure difference between the cabin and the outside atmosphere, limited by the fuselage's structural design and controlled by outflow valves.

Hot compressed air taken from an engine compressor or the APU, used for cabin pressurization, air conditioning, and anti-icing; its loss can affect multiple systems.

Auxiliary Power Unit: a small gas turbine that provides electrical power and bleed air on the ground and can be used as a backup in flight.

A conductive bar distributing electrical power to multiple circuits, which may be fed from generators, the battery, or the APU through switching.

A pressure system supplying pitot impact pressure and static pressure to the airspeed indicator, altimeter, and vertical speed indicator, with blockage causing erroneous readings.

An electrical generator producing alternating current, normally driven by the engine or APU; it supplies the aircraft's electrical buses through rectifiers or transformers.

The height on a precision approach at which a pilot must have the required visual reference to continue to land, otherwise a missed approach is flown.

Runway Visual Range: the distance a pilot can see down the runway from a defined point, measured by transmissometers and reported for low-visibility operations.

A discontinued landing approach in which the pilot applies power, climbs, and follows the missed-approach procedure for another approach or diversion.

The four-digit code a pilot sets on the transponder to identify the aircraft to air traffic control radar; specific codes denote emergencies or radio failure.

The international radiotelephony distress signal, spoken three times and reserved for grave and imminent danger, which requests immediate assistance and priority from air traffic control and other stations.