GCAA CAR-66 Category A Exam flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Pythagoras theorem

In a right-angled triangle the square of the hypotenuse equals the sum of the squares of the other two sides, used to find unknown lengths.

Sine rule

In any triangle, the ratio of each side to the sine of its opposite angle is constant: a/sin A = b/sin B = c/sin C.

Ohm's law

The voltage across a resistor equals current multiplied by resistance (V = IR), the basic relationship for DC circuit calculations.

Series resistance

In a series circuit the total resistance is the sum of the individual resistances and the same current flows through every component.

Parallel resistance

In a parallel circuit the reciprocal of total resistance equals the sum of reciprocals of individual resistances; voltage is common across branches.

Newton's second law

Force equals mass times acceleration (F = ma); weight is the gravitational force W = mg with g about 9.81 m/s².

Pressure formula

Pressure equals force divided by the area over which it acts; in a fluid it increases with depth according to p = ρgh.

Bernoulli's principle

In a moving fluid, an increase in velocity is accompanied by a decrease in static pressure, explaining lift generation on a wing.

Angle of attack

The angle between the wing chord line and the relative airflow; lift rises with it until the critical angle where the wing stalls.

Induced drag

Drag caused by the generation of lift, greatest at low speed and high angle of attack, and reduced by high aspect ratio wings.

Load factor

The ratio of lift to weight; it increases in turns and manoeuvres, raising stall speed and structural loads.

Dihedral effect

Upward wing angle provides lateral stability because a sideslip creates a rolling moment that tends to level the wings.

Flaps function

Trailing-edge flaps increase camber and wing area, raising lift at low speed and adding drag for approach and landing.

Diode function

A semiconductor device that conducts current from anode to cathode when forward biased and blocks reverse current until breakdown voltage.

Transistor gain

In a bipolar transistor, small base current controls a larger collector current; gain beta equals collector current divided by base current.

Zener diode

A diode operated in reverse breakdown that maintains a nearly constant voltage, used as a voltage reference or regulator.

Full-wave rectifier

A bridge of four diodes that converts both halves of an AC cycle into pulsating DC, giving higher output than a half-wave circuit.

Binary place values

Each binary digit represents a power of two; place values double from right to left as 1, 2, 4, 8, 16 and so on.

AND gate

A logic gate whose output is 1 only when all its inputs are 1; otherwise the output is 0.

Flip-flop

A bistable logic circuit that stores one bit of data and forms the basic building block of sequential digital memory.

ARINC 429 bus

A one-way serial data bus using a pair of signal lines, widely used to connect avionics units transmitting digital information.

2024 aluminium alloy

A copper-based aluminium alloy with good fatigue resistance and strength but relatively low corrosion resistance, often Alclad protected.

Anodising

An electrolytic process that thickens the natural oxide layer on aluminium, improving corrosion resistance and paint adhesion.

Composite matrix

The resin in a composite binds and protects the load-carrying fibres and transfers stress between them.

Torque calculation

Torque equals applied force multiplied by the lever length from the fastener axis; values are set with a calibrated torque wrench.

Dye penetrant inspection

A non-destructive method using a coloured penetrant and developer to reveal surface-breaking defects in non-porous materials.

Magnetic particle inspection

A non-destructive test that uses magnetic fields and iron particles to reveal surface and near-surface defects in ferromagnetic materials.

SHELL model

A human factors model relating Software, Hardware, Environment and Liveware, focusing on mismatches at interfaces that cause error.

Hypoxia

Insufficient oxygen reaching body tissues, causing euphoria, impaired judgement and blurred vision at altitude without warning.

Category A privileges

Certifying staff who may issue certificates of release to service for minor scheduled line maintenance and simple defect rectification within authorisation.

Airworthiness Directive

A mandatory instruction issued by the authority requiring inspection or modification of aircraft to restore or maintain airworthiness.

Semi-monocoque structure

Aircraft structure in which the stressed skin, stringers, frames and bulkheads share loads, combining strength with low weight.