GCAA AME Licence Exam cheat sheet

ICAO Annexes are standards and recommended practices; national authorities (e.g. GCAA) issue implementing regulations (CARs) that carry legal force.

Annex 1 covers personnel licensing; Annex 6 covers operation of aircraft; Annex 8 covers airworthiness of aircraft.

A Standard is a mandatory specification; a Recommended Practice is desirable but not mandatory - both are ICAO terms.

An AME licence is issued by the State of registry or the State where maintenance is performed, per national licensing rules.

Aircraft maintenance records must be retained so the history of airworthiness is traceable; retention periods are set by the national regulation.

Maintenance organisation approvals are granted to an organisation, not to an individual; the certifying staff act under that approval.

A Certificate of Airworthiness is issued by the State of registry and remains valid only while maintenance and inspections are kept current.

Language proficiency and medical validity are conditions of licence validity, in addition to technical knowledge and experience.

Fuselage semi-monocoque construction: skin carries shear, stringers and frames stabilise the skin and carry concentrated loads.

Fail-safe design allows a damaged load path to be detected and replaced before residual strength is exceeded; safe-life design retires parts at a fixed life.

Aircraft hydraulic systems use mineral, phosphate-ester or Skydrol-type fluids; never mix fluid types because seals and materials differ.

Cabin pressurisation is controlled by outflow valves; the pressure differential is limited by a relief valve and the structural design limit.

Fuel tanks may be integral (wet wing), bladder type or rigid; venting prevents over-pressure and fuel starvation as fuel is consumed.

Bleed air is taken from the engine compressor for pressurisation and anti-icing; leakage is detected by overheat or leak-detection loops.

Flight controls are powered or manual; a manual reversion or standby system is provided where powered controls are installed.

Landing gear oleo struts absorb landing loads by compressing gas and forcing oil through an orifice; servicing uses nitrogen and hydraulic fluid.

Aircraft DC systems are commonly 28 V; AC systems are typically 115 V 400 Hz, generated by the engine-driven generator or APU.

A shunt in the battery or generator circuit measures current by the voltage drop across a known resistance.

A busbar tie or split-bus arrangement allows one generator to supply essential loads after a generator failure.

Pitot-static instruments: airspeed uses pitot and static pressure; altimeter uses static pressure; vertical speed uses a calibrated leak.

Airspeed indicator errors include position error, instrument error and compressibility error; IAS is not equal to TAS at altitude.

A gyroscopic instrument depends on rigidity in space and precession; an electrically driven gyro needs a power supply and caging facility.

An ILS provides lateral guidance from the localiser and vertical guidance from the glide path; a marker beacon indicates distance checkpoints.

Bonding and shielding reduce electromagnetic interference; a bad bond can cause radio noise and instrument faults.

A gas turbine produces thrust by accelerating a mass of air; a turbofan gains efficiency from the bypass ratio.

Turbine engine stations: intake, compressor, combustion, turbine, exhaust; compressor bleed air is used for cooling and cabin supply.

A turbine engine igniter is normally used only for start; once lit, combustion is self-sustaining.

A piston engine four-stroke cycle: induction, compression, power, exhaust; the camshaft turns at half crankshaft speed in a four-stroke.

Detonation is uncontrolled rapid combustion; pre-ignition is ignition before the spark - both are detected by high cylinder head temperature and rough running.

A turbocharger uses exhaust gas energy to drive a compressor; a wastegate controls boost pressure.

A constant-speed propeller maintains selected RPM by varying blade angle through a governor; oil pressure or counterweights drive the change.

Engine fire detection uses continuous loops or spot detectors; a fire bottle discharges into the engine compartment through a fixed pipe.

The dirty dozen human factors include complacency, distraction, fatigue, pressure, stress, lack of communication, lack of resources and lack of teamwork.

SHEL model: Software, Hardware, Environment, Liveware - the human is the central Liveware element interacting with the others.

A maintenance error is an unintentional act; a violation is a deliberate deviation from a rule or procedure.

The Swiss cheese model: latent and active failures align to breach defences; reporting systems reduce latent failures.

Torque values are applied with a calibrated wrench; a torque wrench is calibrated at defined intervals and recorded.

Lockwire and cotter pins prevent fastener rotation; lockwire must be installed so it pulls the fastener in the tightening direction.

FOD control: tools and parts are accounted for before and after a task; a missing tool must be reported and the aircraft grounded if not found.

A maintenance release is signed only by authorised certifying staff after all required work and inspections are complete.

Lift L = ½ρV²SC_L; induced drag increases with lift coefficient and decreases with aspect ratio.

The four forces are lift, weight, thrust and drag; in steady level flight lift equals weight and thrust equals drag.

Angle of attack is the angle between the chord line and the relative airflow; the critical angle produces the stall.

A stall occurs at a specific angle of attack, not a specific speed; a stalled aircraft can stall at any speed and attitude.

Load factor n = L/W; in a level turn n = 1/cos(bank angle), so a 60° bank gives n = 2.

The centre of pressure moves forward as angle of attack increases on a cambered wing, producing a pitch-up tendency.

Static stability: positive static stability means a disturbance produces a restoring moment; dynamic stability describes the resulting motion over time.

Mach number is TAS divided by local speed of sound; a shock wave forms when local airflow exceeds Mach 1.

Ohm's law: V = IR; power P = VI = I²R = V²/R.

Series resistance: R_total = R1 + R2 + ...; parallel resistance: 1/R_total = 1/R1 + 1/R2 + ...

Capacitive reactance X_C = 1/(2πfC); inductive reactance X_L = 2πfL; impedance Z = √(R² + (X_L − X_C)²).

Torque = force × perpendicular distance; work = force × distance; power = work/time.

Pressure = force/area; 1 bar = 100 kPa; 1 psi ≈ 6.895 kPa.

Density = mass/volume; specific gravity is the ratio of a substance's density to that of water.

Trigonometry: sin = opposite/hypotenuse, cos = adjacent/hypotenuse, tan = opposite/adjacent.

Temperature conversion: °F = (°C × 9/5) + 32; °C = (°F − 32) × 5/9; absolute zero is −273.15 °C.

Aluminium alloys are identified by a four-digit system; 2024 and 7075 are common aircraft alloys, and 2024 requires protective treatment because of its copper content.

Anodising forms a protective oxide layer on aluminium; it is an electrochemical process, not a paint.

Corrosion types: surface (general), galvanic, pitting, intergranular, exfoliation and stress corrosion.

Galvanic corrosion occurs when dissimilar metals are joined in the presence of an electrolyte; the anodic metal corrodes.

Cadmium plating on steel provides sacrificial protection; it must not be used where it contacts aluminium in a corrosive environment without a barrier.

A rivet is identified by head type, alloy and diameter; a solid rivet is set by a bucking bar and a rivet gun or squeezer.

A bolt is graded by strength; AN and MS hardware have specified dimensions and material - do not substitute without approval.

Corrosion prevention includes sealing, drainage, protective coatings and regular inspection of hidden areas.

Airworthiness is maintained by scheduled maintenance, defect rectification, modification control and continued airworthiness records.

A Certificate of Airworthiness is valid only if the aircraft conforms to its type design and is maintained in accordance with the approved programme.

An Airworthiness Directive is mandatory; compliance must be recorded and cannot be deferred unless the AD allows it.

A Service Bulletin is issued by the manufacturer and is not mandatory unless incorporated into an AD or the approved maintenance programme.

A major modification or repair requires approved data and, where applicable, a supplemental type certificate or equivalent approval.

The quality system monitors maintenance and inspection standards; independent inspection is required for critical tasks.

An inspection programme uses scheduled checks (e.g. A, C, D checks) with defined intervals and task content.

A defect found during maintenance must be recorded and rectified; the aircraft is not released until the defect is cleared or deferred under approved procedures.