GCAA CAR-66 B1 Exam key terms

A mandatory instruction issued by the state of registry requiring action on an aircraft, engine, or component to correct an unsafe condition. Compliance is compulsory and must be recorded in the maintenance records.

The set of processes ensuring an aircraft remains in a condition that meets its type design and is safe to operate throughout its service life, covering maintenance, inspections, modifications, and defect control.

A scheduled maintenance document, approved by the competent authority, that specifies the tasks, intervals, and inspections required to keep a particular aircraft type airworthy.

A certification, signed by authorised personnel, confirming that specified maintenance has been completed satisfactorily and the aircraft or component is fit for return to service.

The formal statement, made after maintenance, that the work has been carried out in accordance with approved standards and the item is considered ready for safe operation.

A failure of a planned action to achieve its intended outcome, arising from factors such as misperception, distraction, fatigue, or poor procedure rather than deliberate intent.

A conceptual framework describing human factors as the interaction between Software, Hardware, Environment, and Liveware, used to identify where mismatches can cause error in maintenance work.

A set of twelve commonly cited human-factor precursors to maintenance error, including fatigue, complacency, lack of knowledge, distraction, and pressure, used to raise awareness in training.

A person's accurate perception of the current state of the working environment and how it is likely to change, allowing timely and appropriate decisions.

The internal biological cycle of roughly 24 hours that regulates sleep and alertness; disruption by shift work or night duty can reduce performance and increase error risk.

A state of reduced physical or mental capability resulting from prolonged exertion, lack of sleep, or extended duty, which degrades attention, reaction time, and judgement.

A required check where a second qualified person, not involved in the original task, verifies work such as flight-control connections or engine installation before release.

A document issued by the competent authority approving the design of an aircraft type, engine, or propeller as meeting the applicable airworthiness requirements.

A maintenance personnel licence issued under the applicable regulation, categorised (for example B1 or B2) and endorsed for the aircraft types the holder is qualified to certify.

An approved maintenance organisation permitted to perform maintenance and issue certificates of release to service within the scope of its approval.

A part such as a fastener, bearing, or hydraulic fitting manufactured to a recognised industry or national standard and eligible for use without separate design approval, subject to specified conditions.

A component that meets the type design and is produced or accepted under an approved process, so it may lawfully be fitted to an aircraft.

The turning moment applied to a fastener, measured in newton-metres or pound-inches, controlled to ensure correct clamping load and to prevent loosening or over-stressing.

A safety method in which a fine wire is threaded through fastener heads and twisted to prevent them from rotating loose under vibration.

A split metal pin inserted through a hole in a bolt or shaft and spread at the ends to retain a nut or component and prevent it from working loose.

The electrochemical deterioration of a metal through reaction with its environment, commonly caused by moisture, salt, or dissimilar metal contact, requiring inspection and protective treatment.

Corrosion caused when two dissimilar metals are in electrical contact in the presence of an electrolyte, with the more active metal corroding preferentially.

Progressive structural damage from repeated cyclic loading, which can initiate cracks at stress concentrations even when loads are below the ultimate strength of the material.

A local increase in stress at features such as holes, sharp corners, or scratches, which raises the likelihood of crack initiation and is controlled by careful design and inspection.

The electrical connection of aircraft metallic structure and components to provide a low-resistance path for currents, reducing static build-up and ensuring fault-current return.

The opposition of a material to the flow of electric current, measured in ohms, determined by material, length, cross-section, and temperature.

The relationship stating that current through a conductor equals the voltage across it divided by its resistance, expressed as I equals V over R.

The ability of a component to store electrical charge per unit of voltage, measured in farads, formed by two conductors separated by an insulator.

The property of a circuit that opposes changes in current by developing an electromotive force, measured in henries and central to transformers and motors.

A two-terminal device that conducts current mainly in one direction, used for rectification, protection, and signal control in aircraft electrical and electronic systems.

A three-terminal semiconductor device used to amplify or switch electronic signals, forming the basis of many aircraft electronic control and power circuits.

The angle between an aerofoil's chord line and the relative airflow, which determines lift; exceeding the critical angle causes airflow separation and stall.

A condition in which the airflow separates from an aerofoil because the angle of attack exceeds its critical value, causing a sudden loss of lift and increase in drag.

The aerodynamic force produced perpendicular to the relative airflow, generated by pressure differences over the aerofoil and essential for sustaining flight.

The point at which the total weight of the aircraft is considered to act; its position affects stability and control and must remain within approved limits.

The ratio of the mass airflow through a turbofan's bypass duct to that through the engine core, influencing thrust, efficiency, and noise characteristics.

A disruption of smooth airflow through a compressor caused by excessive angle of attack on the blades, producing a bang, loss of thrust, and possible damage.

A measured temperature of the exhaust gases used to monitor engine performance and limit turbine temperatures during start and operation.

The angle at which a propeller blade is set relative to its plane of rotation, controlling the thrust produced at a given rotational speed.

A propeller whose blade pitch is automatically varied by a governor to maintain a selected rotational speed as engine power or flight conditions change.