CAAB AME B2 Exam key terms

The agreed sequence for evaluating a mathematical expression: brackets first, then powers or roots, then multiplication and division, and finally addition and subtraction, working left to right within each level.

The exponent to which a fixed base must be raised to produce a given number; for example, the base-10 logarithm of 1000 is 3. Used to solve exponential equations and express large ratios compactly.

A ratio of two sides of a right-angled triangle, namely sine, cosine or tangent, that relates an acute angle to side lengths and is used to resolve vectors and analyse alternating waveforms.

The acceleration of a body is directly proportional to the net force acting on it and inversely proportional to its mass, expressed as force equals mass times acceleration when mass is constant.

A turning effect produced by a force acting at a distance from a pivot, calculated as force multiplied by perpendicular distance and measured in newton metres.

Force acting perpendicular to a surface divided by the area of that surface, normally measured in pascals; in aviation it underlies altimetry, airspeed measurement and hydraulic system design.

The point at which the entire weight of a body may be considered to act; its position affects aircraft balance, stability and control and must remain within specified limits.

For a conductor at constant temperature, current is directly proportional to applied voltage and inversely proportional to resistance, giving the relationship voltage equals current multiplied by resistance.

Two rules for electrical networks: the current law states that currents entering a junction equal those leaving, and the voltage law states that voltages around any closed loop sum to zero.

The total opposition a circuit presents to alternating current, combining resistance with reactance from capacitors and inductors; it is measured in ohms and depends on frequency.

The ability of a component to store electrical charge per unit of applied voltage, measured in farads; a capacitor opposes changes in voltage and passes alternating but blocks direct current.

A two-terminal semiconductor device that conducts current mainly in one direction, from anode to cathode, and is used for rectification, protection and signal detection.

A three-terminal semiconductor device with emitter, base and collector whose collector current is controlled by base current, used for amplification and switching in electronic circuits.

A high-gain differential amplifier, usually supplied as an integrated circuit, whose behaviour is set by external feedback components to perform amplification, filtering, comparison and mathematical operations.

A circuit that converts alternating current into pulsating direct current, typically using one or more diodes; a filter is then added to smooth the output.

A digital circuit with one or more binary inputs and a single output that performs a basic Boolean function such as AND, OR, NOT, NAND or NOR.

A digital circuit with two stable output states that stores one bit of data; its output changes only in response to a clock or trigger signal, making it the basis of registers and counters.

An electronic device that samples an analogue voltage and converts it into a coded digital number, allowing measured quantities such as pressure or temperature to be processed by digital systems.

A shared set of electrical conductors, or a defined protocol, over which digital data is transferred between units in an aircraft system; normally only one transmitter talks at a time.

A metal made by combining two or more elements, at least one being a metal, to obtain properties such as greater strength, hardness or corrosion resistance than the pure metal.

Progressive cracking of a material caused by repeated or fluctuating stress below its ultimate strength; a major concern in aircraft structures and a reason for defined inspection intervals.

Corrosion that occurs when two dissimilar metals are in electrical contact in the presence of an electrolyte, causing the more active metal to corrode preferentially.

Any loose object or debris that could be ingested by an engine, jam a control or damage an aircraft; preventing and removing it is a basic maintenance discipline.

Inspection methods such as dye penetrant, magnetic particle, eddy current, ultrasonic and radiography that reveal defects without damaging the component being inspected.

A twisted metallic wire used to secure fasteners and components against vibration-induced loosening; it is installed in a tensioned pattern that prevents further tightening or loosening rotation.

A calibrated hand tool that applies and indicates a specific tightening moment to a fastener; it must be checked against known standards at defined intervals to ensure accuracy.

The angle between the wing chord line and the relative airflow; increasing it raises lift up to the critical angle, beyond which the wing stalls.

A loss of lift caused when the wing exceeds its critical angle of attack, disrupting airflow over the aerofoil; it can occur at any speed or attitude.

The aerodynamic force produced perpendicular to the relative airflow by a wing or aerofoil, arising from pressure differences and dependent on speed, density, area and lift coefficient.

A human factors framework describing the interaction of software, hardware, environment and liveware, with the central liveware representing the person at the centre of the system.

A person's accurate perception and understanding of what is happening around them, including the aircraft state and foreseeable developments, and the ability to project ahead.

A state of self-satisfaction and reduced vigilance, often developing after long periods of routine work, that leads people to miss warnings or skip checks.

A roughly 24-hour cycle in physiological functions such as sleep, alertness and body temperature, which is disturbed by night work and rapid travel across time zones.

A legally binding instruction issued by an airworthiness authority requiring inspection, modification or restriction of an aircraft or component to correct an unsafe condition.

A signed certification that maintenance work has been completed and the aircraft or component is airworthy and fit for return to service within the approved scope.

An approval issued by a state authority confirming that an aircraft, engine or propeller design meets the applicable airworthiness requirements; individual aircraft then receive certificates of airworthiness.

An approved document listing items that may be inoperative while the aircraft remains airworthy, together with the conditions, limitations and procedures for dispatching with those defects.