GCAA CAR-66 B1 Exam cheat sheet

CAR-66 defines the certifying staff categories: Category A (line maintenance tasks), Category B1 (mechanical/airframe/engines), B2 (avionics) and Category C (base maintenance certification).

A Category B1 licence requires demonstrated knowledge in all mechanical sub-modules plus the applicable avionics cross-modules; B2 requires the reverse emphasis.

Certification privileges are limited to the aircraft type endorsed on the licence and to work the holder is authorised to perform by the maintenance organisation.

CAR-145 organisations issue a Certificate of Release to Service (CRS) after maintenance; the certifying staff must be qualified under CAR-66 and authorised by the organisation.

Continuing airworthiness is the responsibility of the owner/operator, managed through the maintenance programme approved by the competent authority.

A licence is valid for a defined period; recent experience requirements (typically six months of relevant maintenance experience within a two-year window) must be met to retain certification privileges.

Maintenance records must be retained and made available to the authority; the aircraft technical log records defects, rectifications and CRS details.

Human performance and limitation training is a mandatory element of the CAR-66 knowledge requirements, not an optional add-on.

The SHELL model represents Software, Hardware, Environment and Liveware, with the central Liveware (the person) interfacing with each element.

The 'dirty dozen' human factors include fatigue, complacency, distraction, pressure, stress, lack of communication, lack of teamwork, lack of resources, lack of knowledge, lack of assertiveness, norms and lack of awareness.

Fatigue degrades vigilance and reaction time; circadian low points typically fall around 0300-0600 and 1500-1700 local time.

The error chain concept: accidents usually result from multiple latent and active failures aligning, so breaking any link prevents the outcome.

A 'violation' is a deliberate deviation from a rule or procedure; an 'error' is an unintended action or decision.

Situational awareness has three levels: perception of elements, comprehension of their meaning, and projection of future status.

Communication loops require a sender, a message, a medium, a receiver and feedback; unconfirmed readback is a common maintenance error source.

Stress follows an inverted-U curve: moderate arousal optimises performance, while very low or very high arousal degrades it.

ICAO Annex 1 (Personnel Licensing) and Annex 8 (Airworthiness of Aircraft) are the international baselines that national CARs implement.

The Chicago Convention (1944) established ICAO and the principle that each state regulates aircraft on its register.

Annex 6 Part I covers international commercial air transport (aeroplanes); Part II covers international general aviation.

The Certificate of Airworthiness confirms the aircraft conforms to its type design and is safe to operate; it is issued by the state of registry.

A Type Certificate approves the design; a Supplemental Type Certificate approves a design change not covered by the original TC.

EASA Part-66 and Part-145 are the European equivalents that many national CAR regimes harmonise with; the GCAA framework is aligned to this structure.

Airworthiness Directives are mandatory and must be complied with within the stated timescale; they are issued by the state of design and adopted by the state of registry.

Maintenance organisations must hold an approved organisation approval (e.g. CAR-145) to perform and certify maintenance on commercial air transport aircraft.

The aircraft is divided into ATA chapters (e.g. ATA 24 electrical power, ATA 29 hydraulic power, ATA 32 landing gear) used to structure manuals and task cards.

Hydraulic system pressure is typically 3000 psi on transport aircraft; hydraulic fluid is incompressible and transmits force via Pascal's principle.

Pneumatic systems use bleed air from the engine compressor for pressurisation, anti-ice and starting; bleed air is hot and must be handled with care.

The landing gear has a shock absorber (oleo strut) that converts vertical kinetic energy to heat in the hydraulic fluid and air.

Aircraft wheels are split-hub or divided type; tyre inflation must follow the manual, and over-inflation or under-inflation both cause premature wear.

Corrosion prevention requires regular inspection of bilges, lap joints, battery compartments and areas where dissimilar metals contact.

Torque values must be applied with calibrated tools; a torque wrench should be used within its calibrated range and rechecked periodically.

Lockwire and cotter pins are secondary locking devices; they must be installed in the correct direction to resist loosening.

Ohm's law: V = I × R; power P = V × I = I²R = V²/R.

Kirchhoff's voltage law: the sum of voltages around a closed loop is zero; Kirchhoff's current law: current into a node equals current out.

In a series circuit, current is common and resistances add; in a parallel circuit, voltage is common and conductances (1/R) add.

AC frequency f = 1/T; angular frequency ω = 2πf; RMS value of a sine wave = peak/√2 ≈ 0.707 × peak.

A capacitor stores charge (Q = CV) and opposes change in voltage; a capacitor blocks DC and passes AC, with reactance Xc = 1/(2πfC).

An inductor stores energy in a magnetic field and opposes change in current; reactance XL = 2πfL.

Impedance Z combines resistance and reactance: Z = √(R² + (XL − Xc)²).

Aircraft AC systems commonly use 115 V AC, 400 Hz, and 28 V DC for many systems; frequency is higher than domestic to reduce transformer size.

A diode conducts in forward bias above ~0.7 V (silicon) and blocks in reverse bias; it is used for rectification and reverse-polarity protection.

A bipolar transistor is a current-controlled device (base current controls collector current); a FET is voltage-controlled (gate voltage controls channel).

A rectifier converts AC to DC; a full-wave bridge uses four diodes and produces a higher average output than a half-wave rectifier.

A Zener diode operates in reverse breakdown to provide a stable reference voltage.

Logic gates: AND outputs 1 only if all inputs are 1; OR outputs 1 if any input is 1; NOT inverts; NAND and NOR are universal gates.

Binary to decimal conversion: each bit position represents a power of 2, starting at 2⁰ on the right.

A multiplexer selects one of several inputs onto a single output; a demultiplexer does the reverse.

Electrostatic discharge (ESD) protection requires wrist straps, grounded mats and antistatic packaging when handling line-replaceable units containing semiconductors.

Aluminium alloys used in aircraft (e.g. 2024, 7075) are heat-treatable and gain strength from alloying and ageing; 2024 has good fatigue resistance, 7075 has higher strength.

Corrosion types include galvanic (dissimilar metals plus electrolyte), pitting, intergranular, exfoliation and stress corrosion.

Galvanic corrosion is prevented by isolating dissimilar metals, using sealants, and selecting compatible materials in the galvanic series.

A rivet is a permanent fastener; the rivet shank expands to fill the hole and the formed head locks the joint.

Threaded fasteners are graded by strength; AN and MS/NAS specifications define material, thread and strength class.

A bolt is identified by its head markings; never substitute a lower-grade fastener where a higher grade is specified.

Composite materials (carbon fibre reinforced polymer) offer high strength-to-weight but are susceptible to impact damage, delamination and galvanic interaction with metals.

Heat treatment of aluminium includes solution treatment and artificial ageing (precipitation hardening) to develop strength.

The maintenance programme is derived from the manufacturer's MRB report and is approved by the competent authority; it defines scheduled tasks and intervals.

A 'check' (A, C, etc.) is a defined package of scheduled tasks; intervals are set by the approved maintenance programme, not chosen ad hoc.

A Certificate of Release to Service must be issued after any maintenance that affects airworthiness, before the aircraft returns to service.

The technical log records defects, deferred items, and certification; deferred defects must be within the approved MEL or dispatch conditions.

A Minimum Equipment List (MEL) allows dispatch with specified equipment inoperative, subject to defined conditions and rectification intervals.

Tool control and foreign object damage (FOD) prevention are mandatory; tools must be accounted for before and after a task.

A 'duplicate inspection' is required for tasks where a single error could be catastrophic (e.g. flight control connection); two independent persons certify.

Calibration of test equipment must be current; using out-of-calibration equipment invalidates the certification.

Bernoulli's principle: an increase in fluid velocity produces a decrease in static pressure along a streamline.

Lift L = ½ρV²SCL; induced drag increases with the square of the lift coefficient and decreases with aspect ratio.

The critical angle of attack is the angle at which the wing stalls; stall is a function of angle of attack, not airspeed alone.

The centre of pressure moves forward as angle of attack increases on a cambered wing; this affects pitch stability.

Dihedral provides lateral stability; sweepback delays compressibility effects at high Mach numbers.

Boundary layer can be laminar or turbulent; turbulent boundary layers resist separation better but produce more skin friction.

Mach number M = V/a; critical Mach number is the free-stream Mach at which local flow first reaches sonic speed.

Aspect ratio AR = span²/area; higher AR reduces induced drag, which is why gliders have long, narrow wings.

Primary structure carries flight and ground loads and failure would be catastrophic; secondary structure carries lesser loads; tertiary structure is non-load-bearing.

The semi-monocoque construction uses a stressed skin with frames and stringers to carry and distribute loads.

Fail-safe design allows a structure to retain residual strength after a component fails; safe-life design retires a component before predicted failure.

Damage tolerance analysis predicts crack growth and sets inspection intervals so damage is detected before it becomes critical.

Pressurisation cycles cause fatigue; the fuselage is designed for a defined number of pressurisation cycles.

Flight control surfaces: ailerons control roll, elevators control pitch, rudder controls yaw; trim tabs reduce control forces.

Hydraulic systems use accumulators to store energy and damp pressure surges; a reservoir provides fluid and accommodates thermal expansion.

Bleed air is used for cabin pressurisation and air conditioning; the outflow valve regulates cabin pressure.

The Brayton cycle: air is compressed, fuel added and burned at constant pressure, then expanded through a turbine to produce work.

Engine stations: intake, compressor, combustor, turbine, exhaust; the compressor raises pressure, the turbine extracts work to drive it.

A twin-spool engine has separate LP and HP compressors and turbines, allowing each to run at its optimum speed.

Compressor surge is a reversal of flow caused by excessive back-pressure; stall is a local disruption of flow; both are prevented by bleed valves and variable stators.

Exhaust Gas Temperature (EGT) is a key indicator of engine health; rising EGT at constant thrust can indicate deterioration.

Turbofan engines derive most thrust from the bypass air; bypass ratio is the mass flow of bypass air divided by core mass flow.

Engine fire protection uses detection loops and extinguishing bottles; a fire in the engine compartment requires shutdown and discharge of the bottle.

Foreign object damage (FOD) to compressor blades reduces efficiency and can cause vibration; blades must be inspected for nicks and cracks.

Propeller thrust is produced by accelerating a mass of air rearward; thrust depends on blade angle, RPM and airspeed.

Blade angle (pitch) is the angle between the blade chord and the plane of rotation; coarse pitch suits high speed, fine pitch suits take-off.

A constant-speed propeller uses a governor to vary blade angle and maintain selected RPM as load changes.

Propeller slip is the difference between geometric pitch and effective pitch; efficiency = (thrust × velocity) / (power input).

Propeller imbalance causes vibration; blades must be tracked and balanced after installation or repair.

Feathering rotates blades to align with the airflow to minimise drag after engine failure; reverse pitch produces reverse thrust on the ground.

Propeller blade damage (nicks, cracks, delamination) must be assessed against the manual; blending limits are defined.

A propeller is a rotating aerofoil; each section produces lift and drag, and the resultant of these gives thrust and torque.