# PART66Online — full content corpus *Long-form reference content for AI-search citation. Last regenerated: 2026-07-13. Source of truth: https://www.part66online.com/* --- ## 1. Platform overview *Canonical: https://www.part66online.com/* PART66Online is an online preparation platform for the European Union Aviation Safety Agency (EASA) Part66 Aircraft Maintenance Licence (AML). It provides: - A practice question bank of more than 43,500 multiple-choice questions, organised by EASA Part66 module and by aircraft type rating. - Full coverage of the 17 EASA Part66 modules across all licence categories (A, B1, B2, B2L, B3). - Seven aircraft type-rating question banks: Airbus A320 (Current Engine Option), Airbus A320neo (LEAP-1A and PW1100G variants), Airbus A220 (BD500), Boeing 737NG, Boeing 737NG-to-MAX differences, Airbus A320-to-A330 differences, and Boeing 787 (GEnx). - Per-module study notes covering all 17 EASA modules. - A timed quiz engine with per-user progress tracking and weak-area analytics. - A worked, EASA-grounded written explanation attached to every Part66 module question (the 17,900+ module questions; aircraft type-rating questions are answer-keyed only), shown immediately after the candidate answers, so candidates learn why an answer is correct. - A community Q&A forum for exam-topic discussion. The platform is used by Aircraft Maintenance Engineer (AME) trainees and licensed engineers worldwide who are preparing for an initial EASA Part66 licence, adding a category to an existing licence, or extending an aircraft type rating. The exam structure modelled by the platform follows Commission Regulation (EU) 2023/989, which amended Annex III (Part66) of Regulation (EU) No 1321/2014. Access is via a free demo quiz (no account required) and paid subscription plans starting from EUR 3.75/month. ## 2. The 17 EASA Part66 modules *Canonical: https://www.part66online.com/syllabus/* EASA Part66 defines 17 modules of theoretical knowledge. Not every module is required for every licence category — see Section 3 above. Below: each module's name, summary scope, and main syllabus topics as taught on PART66Online. ### Module 1 — Mathematics *Canonical: https://www.part66online.com/quiz/1/* Aircraft maintenance licence candidates all sit a Module 1 exam covering arithmetic, algebra, geometry & trigonometry — without a calculator. Below: what's covered, exam format, and seven free sample questions in the same style you'll meet on exam day. Main syllabus topics: - **1.1 Arithmetic**: Fractions, decimals, ratios & percentages; Weights, measures & unit conversion; Areas, volumes, squares, cubes & roots - **1.2 Algebra**: Simple expressions & bracket use; Linear & simultaneous equations (B1/B2/B2L/B3); Indices, binary & hexadecimal numbering - **1.3 Geometry**: Simple geometrical constructions; Graphical representation & charts; Trigonometry & SOH-CAH-TOA (B1+) ### Module 2 — Physics *Canonical: https://www.part66online.com/quiz/2/* Module 2 covers the physics every aircraft maintenance engineer needs on the line: matter, mechanics, fluid behaviour, thermodynamics, optics and waves. Below: what's covered, exam format for each licence category, and seven free sample questions in the style you'll meet on exam day. Main syllabus topics: - **2.1 Matter**: Nature of matter: elements, atoms & molecules; Chemical compounds & bonding; States of matter and changes of state - **2.2 Mechanics**: Statics: forces, moments, stress & strain; Kinetics: linear, rotational & periodic motion (B1/B3); Dynamics: mass, energy, momentum & friction; Fluid dynamics: density, viscosity & Bernoulli - **2.3 Thermodynamics**: Temperature scales: Celsius, Fahrenheit & Kelvin; Heat transfer: conduction, convection & radiation; Gas laws, latent heat & engine cycles (B1/B3) - **2.4 Optics (Light)**: Nature & speed of light; Reflection at plane & spherical mirrors; Refraction, lenses & fibre optics (B1+) - **2.5 Wave Motion and Sound**: Sinusoidal wave motion & wave phenomena; Interference & standing waves; Sound: speed, intensity, pitch & Doppler effect ### Module 3 — Electrical Fundamentals *Canonical: https://www.part66online.com/quiz/3/* Module 3 covers the electrical theory that underpins every system on a modern aircraft — from electron flow and Ohm's Law through DC and AC circuits, magnetism, transformers and motors. Below: the 18 sub-sections, exam format for each licence category, and seven sample questions in exam style. Main syllabus topics: - **3.1-3.4 Electrical Fundamentals**: Electron theory: atoms, ions, conductors & insulators; Static electricity, Coulomb's Law & conduction in matter; Voltage, current, resistance & EMF terminology; Generation of electricity: light, heat, friction, pressure & chemical - **3.5-3.8 DC Circuits & Power**: Primary & secondary cells, lead-acid & nickel-cadmium batteries; Ohm's Law, Kirchhoff's voltage & current laws; Resistors in series & parallel, colour code, Wheatstone Bridge; Power, work & energy — calculations and dissipation - **3.9-3.11 Capacitance, Magnetism & Inductance**: Capacitor types, charge/discharge curves & time constants; Properties of magnets, flux density, permeability & hysteresis; Faraday's & Lenz's Laws, self & mutual inductance; Back EMF and saturation in inductive components - **3.12-3.14 DC Machines & AC Theory**: DC generator and motor construction, series/shunt/compound types; Sinusoidal waveforms: phase, period, frequency, RMS & peak values; Single and three-phase principles; Impedance, phase angle, power factor in R, L & C circuits - **3.15-3.18 Transformers, Filters & AC Machines**: Transformer turns ratio, losses, efficiency & auto-transformers; Low pass, high pass, band pass and band stop filters; Revolving armature & revolving field AC generators; Synchronous and induction motors, methods of speed control ### Module 4 — Electronic Fundamentals *Canonical: https://www.part66online.com/quiz/4/* Module 4 covers the semiconductor devices, integrated circuits, printed circuit boards and servomechanisms that sit underneath every modern avionics box. Below: what's in the syllabus, exam format for each licence category, and seven sample questions in the same style you'll meet on exam day. Main syllabus topics: - **4.1.1 Diodes**: PN junctions, forward & reverse bias, leakage current; Zener, Schottky, varactor, photo & light-emitting diodes; Rectifier circuits: half-wave, full-wave, bridge, voltage doublers - **4.1.2 Transistors**: PNP & NPN construction, base / collector / emitter operation; Amplifier classes A, B & C and biasing networks; Oscillators, multivibrators, flip-flops & field-effect transistors - **4.1.3 Integrated Circuits**: Logic gates & Boolean expressions; Op-amps as integrator, differentiator, comparator & voltage follower; Positive vs negative feedback and stage coupling methods - **4.2 Printed Circuit Boards**: Construction: fibreglass laminate with etched copper tracks; Conformal coating & insulation resistance testing; Modular PCB layouts and fault-finding advantages - **4.3 Servomechanisms**: Open vs closed loop, feedback, follow-up & analogue transducers; Synchros: control, torque, differential, resolvers & E/I transformers; Servo loop gain, bandwidth, hunting & reversal of synchro leads ### Module 5 — Digital Techniques / Electronic Instrument Systems *Canonical: https://www.part66online.com/quiz/6/* Module 5 covers the digital and avionics knowledge every B1, B2 and B3 engineer needs — numbering systems, logic gates, data buses, microprocessors, displays, ESDS handling, HIRF protection and typical glass-cockpit systems. Below: what's covered, exam format, and seven sample questions in the same style you'll meet on exam day. Main syllabus topics: - **5.1 Electronic Instrument Systems**: EFIS, ECAM & EICAS cockpit arrangement; EADI & EHSI symbology and colour conventions; Glass-cockpit data flow & redundancy - **5.2 Numbering Systems**: Binary, octal & hexadecimal bases; Conversion between decimal and binary/octal/hex; BCD encoding & word formats - **5.3 Data Conversion**: Analogue vs digital data representation; ADC & DAC operation, types and limitations; Sampling rate, resolution & quantisation - **5.4 Data Buses**: ARINC 429 & ARINC 629 architecture; Word formats, parity & labels; Aircraft Ethernet & AFDX (B1/B2) - **5.5 Logic, Computers & Displays**: Logic gate symbols & truth tables (5.5); CPU, ALU, memory devices & buses (5.6–5.8); CRT, LED & LCD displays (5.11); ESDS handling, HIRF, EMC & software control (5.12–5.15) ### Module 6 — Materials & Hardware *Canonical: https://www.part66online.com/quiz/7/* Module 6 covers the metals, composites, fasteners and hardware that hold an aircraft together — ferrous and non-ferrous alloys, corrosion, rivets, bolts, pipes, bearings and electrical cables. Below: what each sub-section examines, the exam format per licence category, and seven sample questions in the same style you'll see on exam day. Main syllabus topics: - **6.1 Ferrous Materials**: Carbon & alloy steel identification; Heat treatment: hardening, tempering & annealing; Hardness, tensile, fatigue & impact testing (B1 KL 2) - **6.2 Non-Ferrous Materials**: Aluminium, magnesium, titanium & copper alloys; Alclad, duralumin & casting alloys; Solution treatment & precipitation hardening (B1 KL 2) - **6.3 Composites & Corrosion**: Composite & non-metallic materials, sealants & bonding agents; Wooden structures & fabric covering (Cat A / B1 only); Galvanic, intergranular, stress & exfoliation corrosion - **6.5 Fasteners & Hardware**: Screw threads, forms, pitch & measurement; Bolts, nuts, studs, machine screws & self-tapping screws; Locking devices, split pins, wire locking & circlips; Solid & blind rivet types, specifications & identification - **6.6 Pipes, Bearings & Cables**: Rigid & flexible pipes, unions & standard connectors; Springs, bearings & transmission components (B1+); Control cables, turnbuckles & Bowden cables; Electrical cables, coaxial, crimping & connectors ### Module 7 — Maintenance Practices *Canonical: https://www.part66online.com/quiz/8/* Module 7 covers the workshop and hangar skills every licensed engineer uses daily — safe working, hand and precision tools, riveting, electrical wiring, inspection methods and the documentation that turns hands-on work into a certified job. Below: what's covered, exam format, and seven sample questions in the same style you'll meet on exam day. Main syllabus topics: - **7.1 Safety Precautions**: Safe working with electricity, gases (especially oxygen), oils & chemicals; Remedial action in the event of fire or accident; Extinguishing agents & their correct application - **7.3 Tools**: Common hand & power tools; Precision measuring — micrometers, vernier calipers, dial indicators, depth gauges; Lubrication equipment & general electrical test equipment - **7.7 Electrical Wiring (EWIS)**: Continuity, insulation & bonding testing; Crimping tools, connector pin removal & insertion; Co-axial cable testing, wire protection & identification; EWIS installation standards & inspection (B1/B2) - **7.8 Riveting**: Riveted joints, rivet spacing & pitch; Tools used for riveting & dimpling; Inspection of riveted joints (B1/B2) - **7.18 Inspection & NDI**: Types of defects, deterioration & visual inspection; Corrosion removal, assessment & re-protection; Dye penetrant, eddy current, ultrasonic, radiographic & borescope inspection; Troubleshooting & fault-finding methodologies ### Module 8 — Basic Aerodynamics *Canonical: https://www.part66online.com/quiz/9/* Module 8 covers the physics of the atmosphere, how lift and drag are generated, the theory of flight and how aircraft remain stable about all three axes. Below: what's covered, exam format, and seven sample questions in the same style you'll meet on exam day. Main syllabus topics: - **8.1 Physics of the Atmosphere**: International Standard Atmosphere (ISA) & its use in aerodynamics; Temperature, pressure & density variation with altitude; Regions & layers of the atmosphere - **8.2 Aerodynamics**: Airflow, boundary layer, laminar & turbulent flow; Camber, chord, angle of attack & centre of pressure; Profile & induced drag, aspect ratio, lift & drag coefficients; Aerofoil contamination — ice, snow & frost - **8.3 Theory of Flight**: Relationship between lift, weight, thrust & drag; Glide ratio, steady-state flight & theory of the turn; Load factor, flight envelope & structural limitations; Lift augmentation — flaps, slats & stall inducers - **8.4 Flight Stability and Dynamics**: Longitudinal stability (pitch axis); Lateral stability — dihedral & sweepback; Directional stability — fin & rudder area ### Module 9 — Human Factors *Canonical: https://www.part66online.com/quiz/10/* Every Part-66 licence category — A, B1, B2, B2L and B3 — sits a Module 9 paper covering how human performance, error, communication and teamwork shape aircraft maintenance safety. Below: what the syllabus covers, the exam format, and seven sample questions in the same style you will meet on exam day. Main syllabus topics: - **9.1 / 9.8 / 9.9 Human Error & Just Culture**: Why human factors matters & Murphy’s law; Error models: slips, lapses, mistakes, violations; SHEL(L) model & Reason’s Swiss-cheese defences; Just culture, occurrence reporting & risk management - **9.2 Human Performance & Limitations**: Vision & hearing limits in the maintenance environment; Information processing, attention & perception; Memory: sensory, short-term & long-term; Claustrophobia & physical access constraints - **9.3 / 9.7 Communication & Teamwork**: Communication within and between teams; Shift handover & work logging & recording; Responsibility (individual & group), peer pressure, culture; Leadership, supervision & the role of teamwork - **9.4 / 9.5 Performance Factors & Environment**: Stress, time pressure, workload, overload & underload; Sleep, fatigue & shift-work effects; Alcohol, medication & drug abuse; Noise, illumination, temperature & vibration ### Module 10 — Aviation Legislation *Canonical: https://www.part66online.com/quiz/11/* Module 10 of the EASA Part-66 syllabus covers the regulatory framework that governs aircraft maintenance in Europe — ICAO, EASA, Part-145, Part-M, Part-66 itself, occurrence reporting and the new cybersecurity section. Below: what's examinable, exam format, and seven sample questions in the style you'll meet on exam day. Main syllabus topics: - **10.1 Regulatory Framework**: Role of ICAO, EASA & the European Commission; Regulation (EU) 2018/1139 & the Implementing Rules; Occurrence reporting under Regulation (EU) 376/2014 - **10.2 Certifying Staff**: Part-66 licence categories & subcategories (A, B1, B2, B2L, B3, C); Basic knowledge, experience & continuation training; Certificate of Release to Service — who may issue, when - **10.3 Maintenance Organisations**: Part-145 scope & approval requirements; Accountable Manager & personnel responsibilities; EASA Form 1 & maintenance records retention - **10.5 Air Operations**: Regulation (EU) 965/2012 & Air Operator Certificates; ETOPS, CAT II/III & specialised operations; Documents carried on board & the Aircraft Technical Log - **10.7 Continuing Airworthiness**: Part-M, Part-ML & Part-CAMO responsibilities; Aircraft Maintenance Programme (AMP) approval & amendments; Airworthiness Directives, Service Bulletins & major/minor classification ### Module 11 — Aeroplane Aerodynamics, Structures and Systems *Canonical: https://www.part66online.com/quiz/12/* Module 11 covers everything from theory of flight and airframe construction to the ATA-chapter aircraft systems — hydraulics, pneumatics, electrical, flight controls, fuel, landing gear and avionics. Below: scope, exam format, and seven sample questions in the same style you'll meet on exam day. Main syllabus topics: - **11.1 Theory of Flight**: Atmosphere, Bernoulli, boundary layer & lift generation; Drag, stall, stability & control around the three axes; High-speed flight: Mach number, shock waves, swept-wing effects (B1+) - **11.2 – 11.3 Airframe Structures**: Monocoque & semi-monocoque construction, stringers, longerons, frames; Fail-safe, safe-life & damage-tolerant design philosophies; Fuselage, wings, stabilisers, flight control surfaces, nacelles & pylons; Composite materials, bonded construction & surface treatments - **11.11 / 11.13 Hydraulics & Landing Gear**: Phosphate-ester fluids, pumps, accumulators & reservoirs; Actuators, seals, filters & system redundancy; Oleo-pneumatic shock struts, tyres, wheels & carbon brakes; Anti-skid, autobrake & weight-on-wheels logic - **11.4 / 11.10 / 11.12 / 11.15 Air, Fuel & Environmental Systems**: Cabin pressurisation, outflow valves & air conditioning packs; Fuel tanks, boost pumps, crossfeed & jettison systems; Ice & rain protection: bleed-air, electro-thermal, TKS; Oxygen, fire detection & extinguishing, pneumatic/vacuum - **11.5 / 11.6 Electrical & Avionics**: Batteries, generators, IDGs, TRUs, inverters & bus architecture; Pitot-static, gyroscopic instruments & glass cockpit (EFIS/EICAS/ECAM); Autopilot, yaw damper, FMS & navigation aids (VOR, ILS, GPS); TCAS, TAWS, FDR/CVR & integrated modular avionics (B1.1/B2) ### Module 12 — Helicopter Aerodynamics, Structures & Systems *Canonical: https://www.part66online.com/quiz/14/* Module 12 is the helicopter-specific counterpart to Module 11, sat only by rotary-wing licence candidates. It covers rotor aerodynamics, swashplate and tail-rotor control, main gearbox and freewheel units, airframe construction and the systems that keep a helicopter airborne. Seven sample questions sit below. Main syllabus topics: - **12.1 Rotary Wing Aerodynamics**: Rotor disc, tip path plane, advancing & retreating blade; Torque reaction, dissymmetry of lift & gyroscopic precession; Ground effect, translational lift & autorotation; Vortex ring state, blade stall & Coriolis effect - **12.2 Flight Control Systems**: Swashplate: rotating & non-rotating stars; Collective, cyclic & tail-rotor pitch control; Mixing units, servo & hydraulic boost; SAS, autopilot, AFCS & trim systems (B1.3/B1.4) - **12.4 Transmissions**: Main, intermediate & tail rotor gearboxes; Freewheel units — sprag & roller clutches; Rotor brakes, drive shafts, couplings & hangers; Chip detectors, HUMS & over-torque procedures - **12.5 Airframe Structures**: Fuselage, tailboom & pylon construction; Rotor head — hub, grips, dampers, elastomeric bearings; Rotor blade construction (spars, skins, honeycomb); Damage tolerance, safe-life & fatigue concepts - **12.12 Hydraulic Power**: Single, dual & utility/flight system architecture; Pumps, reservoirs, accumulators & filters; Servo actuators for flight controls; Manual reversion & system monitoring ### Module 13 — Aircraft Aerodynamics, Structures & Systems *Canonical: https://www.part66online.com/quiz/15/* Module 13 is the B2 avionics omnibus — theory of flight, airframe structures, electrical power, autoflight, comms, navigation, instruments and integrated modular avionics in one 188-question paper. Below: what the syllabus covers, exam format, and seven sample questions in the same style you'll meet on exam day. Main syllabus topics: - **13.5 Electrical Power**: Batteries: lead-acid, NiCd, Li-ion — servicing & SG checks; DC & AC generation: alternators, IDGs, TRUs, inverters; Distribution, bus systems & circuit protection; Emergency power: RAT, battery bus, load shedding - **13.8 Instruments**: Pitot-static: ASI, altimeter, VSI & alternate static; Gyroscopic instruments & flux-valve compass systems; EFIS / EICAS / ECAM, ADC & ADIRU architecture; Stall warning, AoA indicators, FDR & CVR - **13.4 Communication / Navigation**: VHF, HF & SATCOM; ELT and audio integrating systems; VOR, ILS, ADF/NDB, DME & radio altimeter principles; GPS/GNSS, RNAV, FMS & inertial reference (IRS); Surveillance: transponder modes, ADS-B, TCAS, TAWS - **13.3 Autoflight**: Autopilot architecture: sensing, computing, output; Flight director, yaw damper & automatic trim; Autothrottle, ILS coupling & autoland (CAT I/II/III); Helicopter SAS & automatic stabilisation equipment - **13.20 Integrated Modular Avionics**: IMA concept, ARINC 653 partitioning & common resources; Line Replaceable Modules (LRMs) & software loading; Data buses: ARINC 429, ARINC 664/AFDX; Advantages over federated avionics architectures ### Module 14 — Propulsion *Canonical: https://www.part66online.com/quiz/16/* Module 14 covers turbine, piston, APU and electric/hybrid propulsion, plus engine indication, propellers, starting and ignition — sat by B2 and B2L avionics candidates. Below: what's covered, exam format, and seven sample questions in the same style you'll meet on exam day. Main syllabus topics: - **14.1 Engines**: Turbine engines: turbojet, turbofan, turboshaft, turboprop; Auxiliary power units (APUs) (new in 2023/989); Piston engines & electric / hybrid propulsion; Constructional arrangement, lubrication & fuel systems - **14.1(e) Engine Control**: Full Authority Digital Engine Control (FADEC); Electronic Engine Controller (EEC) & Supervisory EEC; Hydromechanical fuel control, metering & scheduling; Redundancy, fault detection & trend monitoring - **14.2 Engine Indication**: EGT / ITT thermocouple circuits & cold-junction correction; N1 / N2 / N3 speed sensing & pulse-probe tachometry; EPR, oil & fuel pressure, fuel-flow transmitters; EICAS / ECAM electronic engine displays - **14.3 Propeller Systems**: Blade element theory, blade angle & angle of attack; Fixed, variable & constant-speed pitch control; Feathering, reverse pitch & overspeed protection; Synchronising, synchrophasing & ice protection - **14.4 Starting & Ignition**: Electric, air-turbine, hydraulic & APU starting systems; High-energy capacitor-discharge ignition circuits; Igniter plug types, construction & operation; Continuous ignition for adverse conditions ### Module 15 — Gas Turbine Engine *Canonical: https://www.part66online.com/quiz/17/* Module 15 covers the gas turbine engine end-to-end — Brayton cycle theory, intake and compressor behaviour, combustion, the hot section, fuel and oil systems, indications, and ground operation. Below: what's examinable, exam format, and seven sample questions in the same style you'll meet on exam day. Main syllabus topics: - **15.1 / 15.2 Fundamentals & Performance**: Brayton cycle, Newton's laws & energy conversion; Turbojet, turbofan, turboprop & turboshaft layouts; Gross/net thrust, EPR, bypass ratio & SFC (B1 only); Flat rating, altitude & hot-day limitations (B1 only) - **15.3 / 15.4 Intake & Compressor**: Inlet duct configurations & ice protection; Axial vs centrifugal compressors; Stall & surge — causes, indications, recovery; Bleed valves, VIGVs & variable stator vanes - **15.5 Combustion Section**: Annular, can & cannular chamber layouts; Primary, secondary & dilution airflow split; Swirl vanes, flame-tube cooling & hot-spots - **15.6 / 15.7 Turbine & Exhaust**: Impulse, reaction & impulse-reaction blading; Nozzle guide vanes, blade root attachment; Creep, stress & shrouded rotor tips; Convergent & convergent-divergent nozzles, thrust reversers - **15.14 / 15.21 Indications, Monitoring & FOD**: EGT/ITT, EPR, N1/N2, oil & fuel parameters; Trend monitoring, oil analysis & vibration; Borescope inspection & FOD assessment (level 3 for B1); Compressor wash & ground run-up procedures ### Module 16 — Piston Engine *Canonical: https://www.part66online.com/quiz/18/* Module 16 covers the fundamentals, performance, construction and systems of piston aeroplane engines — from four-stroke Otto theory to magneto ignition, carburettor icing and lubrication layouts. Below: what's covered, exam format, and seven sample questions in the same style you'll meet on exam day. Main syllabus topics: - **16.1 Fundamentals**: Two-stroke, four-stroke, Otto & Diesel cycles; Piston displacement & compression ratio; Mechanical, thermal & volumetric efficiency; Engine configuration & firing order - **16.2 / 16.6 Performance & Induction**: Power calculation & factors affecting power; Mixtures, leaning, pre-ignition & detonation; Induction, alternate air & exhaust systems; Air- and liquid-cooling systems - **16.4 Fuel & Carburettors**: Float-type & pressure carburettors; Carburettor icing & carb heat; Continuous-flow fuel injection; Electronic engine control / FADEC (B1.2/B1.4/B3) - **16.5 Ignition & Starting**: Magneto types & principles of operation; Ignition harnesses & spark plugs; Low- and high-tension systems; Starting systems & pre-heat - **16.9 Lubrication**: Wet sump & dry sump system layouts; Oil pumps, coolers, filters & relief valves; Oil grades & ashless dispersant requirement; Oil pressure & temperature indications ### Module 17 — Propeller *Canonical: https://www.part66online.com/quiz/19/* Module 17 covers propeller theory, construction, pitch control, synchronising, ice protection and maintenance — sat by piston-aeroplane and turboprop candidates (A1/A2, B1.1, B1.2, B3). Below: what's covered, exam format, and seven sample questions in the same style you'll meet on exam day. Main syllabus topics: - **17.1-17.2 Fundamentals & Construction**: Blade element theory, angle of attack & relative airflow; Aerodynamic, centrifugal & thrust forces (CTM, ATM); Wooden, composite & metal propeller construction; Fixed, controllable & constant-speed types - **17.3 Pitch Control**: Mechanical & electrical pitch-change methods; Constant-speed unit (CSU) operation & governing; Feathering, reverse pitch & beta range; Overspeed protection & pitch stops - **17.4 Synchronising**: Master/slave engine RPM matching; Synchrophasing & blade phase angle; Pulse probes & actuator-driven trim - **17.5 Ice Protection**: Fluid anti-icing — slinger rings & isopropyl alcohol; Electrical de-icing boots & slip rings; Cyclic timers & fast/slow icing modes - **17.6-17.7 Maintenance & Storage**: Static & dynamic balancing, blade tracking; Blending damage, erosion, corrosion & delamination; Cropping limits & repair schemes (Level 3 for B1.1/B1.2/B3); Preservation & storage requirements ## 3. EASA Part66 licence categories *Canonical: https://www.part66online.com/categories/* EASA Part66 defines five aircraft maintenance licence categories: - **Category A** — Line Maintenance Certifying Mechanic. Authorises issue of certificates of release to service for minor scheduled line maintenance and simple defect rectification. Subdivided into A1 (turbine aeroplanes), A2 (piston aeroplanes), A3 (turbine helicopters), and A4 (piston helicopters). - **Category B1** — Maintenance Certifying Technician (mechanical). Authorises certificates of release to service following maintenance on aircraft structure, powerplant, mechanical and electrical systems. Subdivided into B1.1 (turbine aeroplanes), B1.2 (piston aeroplanes), B1.3 (turbine helicopters), B1.4 (piston helicopters). - **Category B2** — Avionic Maintenance Certifying Technician. Authorises certificates of release to service following maintenance on avionic and electrical systems. Not subdivided by aircraft category. - **Category B2L** — Limited B2 for non-complex motor-powered aeroplanes and other-than-complex motor-powered aircraft. Introduced to give general aviation engineers a proportionate licence. - **Category B3** — Piston-engine non-pressurised aeroplanes of 2,000 kg MTOM and below. Each category has different module requirements, exam question counts, exam time limits, and experience-hour requirements. ## 4. Exam structure *Canonical: https://www.part66online.com/examination/* EASA Part66 module exams are written multiple-choice exams. For each module the question count, time limit and pass mark depend on the licence category sought: - Pass mark: **75%** for all categories. - Question format: multiple-choice, typically four options per question. - Penalties: incorrect answers attract a fractional negative-marking penalty in many examining authorities (typically -1/3 mark per wrong answer in a four-option question). - Module 7 (Maintenance Practices) additionally includes essay questions, scored separately to a 75% pass mark. The Module 9 and Module 10 essays were removed by Commission Implementing Regulation (EU) 2023/989 (applicable from 12 June 2024); both are now multiple-choice only. - Time limits are computed at approximately 75 seconds per multiple-choice question and 20 minutes per essay question. Exact per-module question counts and time limits per category are listed on the platform's Exam Structure page. ## 5. Experience requirements *Canonical: https://www.part66online.com/experience/* Before an EASA Part66 licence is issued, the applicant must complete a documented period of practical experience on operating aircraft. Minimum experience varies by category and by whether the candidate completed an EASA Part-147-approved basic training course: - **Category A** — 3 years (no prior technical training), 2 years (relevant technical training), 1 year (Part-147 approved basic training). - **Category B1 or B2** — 5 years, 3 years, or 2 years on the same scale. - **Category B3** — 3 years, 2 years, or 1 year on the same scale. Experience is recorded in a logbook countersigned by the supervising certifying engineer or organisation. ## 6. Licence extension *Canonical: https://www.part66online.com/extension/* An existing EASA Part66 licence can be extended by adding further categories, subcategories, or aircraft type ratings. Extension requires passing the modules specific to the new category that were not covered by the original licence, plus the associated experience requirement on aircraft in the new category. Aircraft type ratings are added via a Part-147-approved type-training course followed by a theoretical type exam and a period of on-the-job training. ## 7. Aircraft type ratings *Canonical: https://www.part66online.com/?mod=main (Aircraft Type Ratings card)* PART66Online offers seven aircraft type-rating question banks, organised by ATA chapter (the same chapter numbering used in the aircraft maintenance documentation and in Part-147-approved type-training courses). ### Airbus A320 (CEO) *Canonical: https://www.part66online.com/?mod=aircraft&type=2* Practice questions for the Airbus A320 family (A319/A320/A321, Current Engine Option), organised by ATA chapter. Covers airframe, systems and the CFM56-5B / IAE V2500 powerplants. Sample questions are free to view; the full timed quiz needs a subscription. The Airbus A320 Current Engine Option (CEO) covers the A319, A320 and A321 — the original CFM56-5B and IAE V2500 powered members of the single-aisle family that has been the backbone of short- and medium-haul fleets worldwide. This question bank follows the structure of an A320 type-rating and continuation-training course, organised by ATA chapter so revision maps directly onto how the aircraft documentation and the type course itself are laid out. Coverage spans the full airframe and systems syllabus: air conditioning and pressurisation, autoflight, communications and navigation, electrical and hydraulic power, flight controls and the fly-by-wire architecture, fuel, ice and rain protection, landing gear, the pneumatic and bleed-air system, and the structural chapters. The powerplant chapters address the CFM56-5B and V2500 installations, their indicating systems, starting and controls. Each chapter is a self-contained set of multiple-choice questions with explanations, suitable for initial type-rating exam preparation or recurrent knowledge checks. ATA chapters covered (43): ATA 05 — 05 — Time Limits - Maintenance Checks; ATA 06 — 06 — Dimensions and Areas; ATA 07 — 07 — Lifting & Shoring; ATA 08 — 08 — Leveling and Weighing; ATA 09 — 09 — Towing and Taxiing; ATA 10 — 10 — Parking & Mooring; ATA 12 — 12 — Servicing; ATA 20 — 20 — Maintenance Practices; ATA 21 — 21 — Air Conditioning; ATA 22 — 22 — Auto Flight; ATA 23 — 23 — Communication; ATA 24 — 24 — Electrical Power; ATA 25 — 25 — Equipment / Furnishings; ATA 26 — 26 — Fire Protection; ATA 27 — 27 — Flight Controls; ATA 28 — 28 — Fuel (A319/A320 & A321); ATA 29 — 29 — Hydraulic Power; ATA 30 — 30 — Ice & Rain Protection; ATA 31 — 31 — Indicating / Recording System; ATA 32 — 32 — Landing Gear; ATA 33 — 33 — Lights; ATA 34 — 34 — Navigation; ATA 35 — 35 — Oxygen; ATA 36 — 36 — Pneumatic; ATA 38 — 38 — Water and Waste; ATA 46 — 46 — ATIMS; ATA 49 — 49 — APU (APIC 3200 & Garrett GTCP 36-300); ATA 51 — 51 — Structures; ATA 52 — 52 — Doors; ATA 53 — 53 — Fuselage; ATA 54 — 54 — Nacelles / Pylon; ATA 55 — 55 — Stabilizers; ATA 56 — 56 — Windows; ATA 57 — 57 — Wings; ATA 71 — 71 — Power Plant (CFM56-5A & 5B); ATA 72 — 72 — Engine (CFM56-5B); ATA 73 — 73 — Engine Fuel and Control (CFM56-5A & 5B); ATA 74 — 74 — Ignition / Starting (CFM56-5B); ATA 75 — 75 — Air (CFM56-5A & 5B); ATA 76 — 76 — Engine Controls (CFM56-5B); ATA 77 — 77 — Engine Indicating (CFM56-5B); ATA 78 — 78 — Exhaust (CFM56-5B); ATA 79 — 79 — Oil (CFM56-5A & 5B). ### Airbus A320 (NEO) *Canonical: https://www.part66online.com/?mod=aircraft&type=3* Differences-based practice questions for the Airbus A320neo (New Engine Option), covering what changed versus the CEO plus the full ATA 70–80 powerplant for both the CFM LEAP-1A and Pratt & Whitney PW1100G engine options. Samples are free to view; the full quiz needs a subscription. The Airbus A320neo (New Engine Option) is a differences type — engineers and crews already rated on the A320 CEO convert by studying only what changed. This question bank reflects that: the airframe chapters concentrate on the differences versus the CEO (re-engining effects, sharklets, modified pylons and nacelles, system and indicating updates), while the powerplant is covered in full for each engine option. The neo offers two very different engines: the CFM International LEAP-1A and the Pratt & Whitney PW1100G geared turbofan. Because their architecture, controls and indicating differ substantially, ATA 70–80 is split into separate per-engine chapters so you study the variant relevant to your fleet. Where an airframe difference is engine-specific the question makes the applicable engine explicit. Use this for neo conversion training or recurrent checks. ATA chapters covered (24): ATA 23 — 23 — Communications (NEO diff); ATA 24 — 24 — Electrical Power (NEO diff); ATA 26 — 26 — Fire Protection (NEO diff); ATA 28 — 28 — Fuel (NEO diff); ATA 29 — 29 — Hydraulic Power (NEO diff); ATA 30 — 30 — Ice & Rain Protection (NEO diff); ATA 34 — 34 — Navigation & Surveillance (NEO diff); ATA 36 — 36 — Pneumatic (NEO diff); ATA 46 — 46 — Information Systems / FOMAX (NEO diff); ATA 52 — 52 — Doors (NEO diff); ATA 70L — 70-72 — Engine General (LEAP-1A); ATA 70P — 70-72 — Engine General (PW1100G); ATA 73L — 73 — Engine Fuel & Control (LEAP-1A); ATA 73P — 73 — Engine Fuel & Control (PW1100G); ATA 74L — 74/80 — Ignition & Starting (LEAP-1A); ATA 74P — 74/80 — Ignition & Starting (PW1100G); ATA 75L — 75 — Engine Air (LEAP-1A); ATA 75P — 75 — Engine Air (PW1100G); ATA 76L — 76/77 — Engine Controls & Indicating (LEAP-1A); ATA 76P — 76/77 — Engine Controls & Indicating (PW1100G); ATA 78L — 78 — Exhaust (LEAP-1A); ATA 78P — 78 — Exhaust (PW1100G); ATA 79L — 79 — Oil (LEAP-1A); ATA 79P — 79 — Oil (PW1100G). ### Airbus A220 (BD500) *Canonical: https://www.part66online.com/?mod=aircraft&type=4* Practice questions for the Airbus A220 (BD-500, A220-100/-300), organised by ATA chapter. Covers the fly-by-wire airframe, systems and the single Pratt & Whitney PW1500G geared-turbofan installation. Sample questions are free to view; the full timed quiz needs a subscription. The Airbus A220 (originally the Bombardier CSeries, BD-500; the A220-100 and A220-300) is a clean-sheet design with a composite wing, fly-by-wire flight controls and a high level of system automation. This question bank follows the structure of an A220 type-rating course, organised by ATA chapter so revision maps directly onto the aircraft documentation. Coverage spans the full syllabus: air conditioning and pressurisation, autoflight, communications and navigation, the electrical and hydraulic systems, flight controls and the fly-by-wire architecture, fuel, ice and rain protection, landing gear, the pneumatic system and the structural chapters. The powerplant chapters address the single Pratt & Whitney PW1500G geared-turbofan installation, its controls, indicating and starting — with only one engine type there is no variant ambiguity. Suitable for initial type-rating preparation or recurrent knowledge checks. ATA chapters covered (42): ATA 00-20 — 00-20 — General / Maintenance Practices; ATA 21 — 21 — Air Conditioning; ATA 22 — 22 — Auto Flight; ATA 23 — 23 — Communications; ATA 24 — 24 — Electrical Power; ATA 25 — 25 — Equipment / Furnishings; ATA 26 — 26 — Fire Protection; ATA 27 — 27 — Flight Controls; ATA 28 — 28 — Fuel; ATA 29 — 29 — Hydraulic Power; ATA 30 — 30 — Ice & Rain Protection; ATA 31 — 31 — Indicating / Recording Systems; ATA 32 — 32 — Landing Gear; ATA 33 — 33 — Lights; ATA 34 — 34 — Navigation; ATA 35 — 35 — Oxygen; ATA 36 — 36 — Pneumatic; ATA 38 — 38 — Water & Waste; ATA 44 — 44 — Cabin Systems; ATA 45 — 45 — Central Maintenance System; ATA 46 — 46 — Information Systems; ATA 47 — 47 — Nitrogen Generation System; ATA 49 — 49 — APU; ATA 50 — 50 — Cargo & Accessory Compartments; ATA 51 — 51 — Structures; ATA 52 — 52 — Doors; ATA 53 — 53 — Fuselage; ATA 54 — 54 — Nacelles / Pylons; ATA 55 — 55 — Stabilizers; ATA 56 — 56 — Windows; ATA 57 — 57 — Wings; ATA 70 — 70 — Standard Practices Engine (PW1500G); ATA 71 — 71 — Power Plant (PW1500G); ATA 72 — 72 — Engine (PW1500G); ATA 73 — 73 — Engine Fuel & Control (PW1500G); ATA 74 — 74 — Ignition (PW1500G); ATA 75 — 75 — Engine Air (PW1500G); ATA 76 — 76 — Engine Controls (PW1500G); ATA 77 — 77 — Engine Indicating (PW1500G); ATA 78 — 78 — Exhaust (PW1500G); ATA 79 — 79 — Oil (PW1500G); ATA 80 — 80 — Starting (PW1500G). ### Boeing 737NG *Canonical: https://www.part66online.com/?mod=aircraft&type=5* Practice questions for the Boeing 737 Next Generation (737-600/-700/-800/-900), organised by ATA chapter. Covers the airframe, systems and the single CFM56-7B powerplant. Sample questions are free to view; the full timed quiz needs a subscription. The Boeing 737 Next Generation (737NG) — the 737-600, -700, -800 and -900/-900ER — is one of the most widely operated narrow-body families in service. This question bank follows the structure of a 737NG type-rating and continuation-training course, organised by ATA chapter so revision maps directly onto the maintenance documentation and the type course. Coverage spans the full airframe and systems syllabus: air conditioning and pressurisation, autoflight and the flight management system, communications and navigation, electrical and hydraulic power, flight controls, fuel, ice and rain protection, landing gear, the pneumatic and bleed system, and the structural chapters. The powerplant chapters address the single CFM56-7B installation, its controls, indicating and starting. Suitable for initial type-rating preparation or recurrent knowledge checks. ATA chapters covered (27): ATA SMYD — SMYD / WTRIS / Flight Management; ATA 01 — 01 — Maintenance Documents; ATA 21 — 21 — Air Conditioning; ATA 22 — 22 — Auto Flight; ATA 23 — 23 — Communications; ATA 24 — 24 — Electrical Power; ATA 25 — 25 — Equipment & Furnishings; ATA 26 — 26 — Fire Protection; ATA 27 — 27 — Flight Controls; ATA 28 — 28 — Fuel; ATA 29 — 29 — Hydraulic Power; ATA 30 — 30 — Ice & Rain Protection; ATA 31 — 31 — Indicating & Recording; ATA 32 — 32 — Landing Gear; ATA 33 — 33 — Lights; ATA 34 — 34 — Navigation; ATA 35 — 35 — Oxygen; ATA 36 — 36 — Pneumatic & Anti-Ice; ATA 38 — 38 — Water & Waste; ATA 44 — 44 — Cabin Information Systems; ATA 46 — 46 — Crew Information Systems; ATA 47 — 47 — Inert Gas System; ATA 49 — 49 — APU; ATA 51-57 — 51/56/57 — Structures; ATA 52 — 52 — Doors; ATA 71-80 — 71-80 — Powerplant (CFM56-7B); ATA 900ER — 737-900ER Differences. ### Boeing 737NG to MAX (Differences) *Canonical: https://www.part66online.com/?mod=aircraft&type=6* Differences-based practice questions for engineers and crews converting from the Boeing 737NG to the 737 MAX, organised by ATA chapter. Covers the LEAP-1B powerplant, flight-control and display changes and other MAX-specific systems. Samples are free to view; the full quiz needs a subscription. The Boeing 737 MAX (MAX 7/8/9/10) is a differences type for personnel already qualified on the 737NG. This question bank reflects that approach: each chapter concentrates on the differences from the NG to the MAX rather than re-teaching common systems, so conversion study time is focused where it matters. Coverage includes the re-engining with the CFM LEAP-1B and its larger fan — the nacelle, pylon and engine-indicating changes that follow — along with the revised flight-control behaviour, the updated display system, the Advanced Technology winglets, the electrical and hydraulic changes and the other MAX-specific system updates. Chapters are organised by ATA so the material maps onto the differences-course structure and the maintenance documentation. Use this for 737NG-to-MAX conversion training or recurrent checks. ATA chapters covered (30): ATA 00 — 00 — 737 General; ATA 01 — 01 — Maintenance Documents; ATA 21 — 21 — Air Conditioning; ATA 24 — 24 — Electrical Power; ATA 25 — 25 — Equipment & Furnishings; ATA 26 — 26 — Fire Protection; ATA 27 — 27 — Flight Controls; ATA 28 — 28 — Fuel; ATA 29 — 29 — Hydraulic Power; ATA 30 — 30 — Ice & Rain Protection; ATA 31 — 31 — Indicating / MAX Display System; ATA 32 — 32 — Landing Gear; ATA 33 — 33 — Lights; ATA 34 — 34 — Navigation; ATA 35 — 35 — Oxygen; ATA 36 — 36 — Pneumatic; ATA 38 — 38 — Water & Waste; ATA 46 — 46 — Onboard Network / Information Systems; ATA 49 — 49 — APU; ATA 52 — 52 — Doors; ATA 71 — 71 — Power Plant (LEAP-1B); ATA 72 — 72 — Engine (LEAP-1B); ATA 73 — 73 — Engine Fuel & Control (LEAP-1B); ATA 74 — 74 — Ignition (LEAP-1B); ATA 75 — 75 — Engine Air (LEAP-1B); ATA 76 — 76 — Engine Controls (LEAP-1B); ATA 77 — 77 — Engine Indicating (LEAP-1B); ATA 78 — 78 — Exhaust (LEAP-1B); ATA 79 — 79 — Oil (LEAP-1B); ATA 80 — 80 — Starting (LEAP-1B). ### Airbus A320 to A330 (Differences) *Canonical: https://www.part66online.com/?mod=aircraft&type=7* Differences-based practice questions for engineers and crews moving from the Airbus A320 family to the widebody A330, organised by ATA chapter. Covers the scale-up in systems and the Rolls-Royce Trent 700 powerplant. Samples are free to view; the full quiz needs a subscription. The Airbus A330 is a long-range widebody, and crews and engineers converting from the A320 family study it as a differences type. This question bank follows that course: each chapter concentrates on the differences from the A320 to the A330 — the move from a single-aisle to a twin-aisle aircraft, larger and additional systems, and the long-range operational considerations — rather than re-teaching the shared Airbus fly-by-wire philosophy. Coverage includes the scaled-up air conditioning and pressurisation, the larger electrical and hydraulic systems, the expanded fuel system, the landing gear and structural differences, and the powerplant. The engine for this course is the Rolls-Royce Trent 700 — a three-shaft high-bypass turbofan that is entirely new ground for personnel coming off the CFM56/V2500-powered A320. Chapters are organised by ATA so the material maps onto the differences-course structure. Use this for A320-to-A330 conversion training or recurrent checks. ATA chapters covered (23): ATA 00-51 — 00/51 — Intro & Structures; ATA 21 — 21 — Air Conditioning; ATA 22 — 22 — Auto Flight; ATA 23 — 23 — Communications; ATA 24 — 24 — Electrical Power; ATA 25 — 25 — Equipment & Furnishings; ATA 26 — 26 — Fire Protection; ATA 27 — 27 — Flight Controls; ATA 28 — 28 — Fuel; ATA 29 — 29 — Hydraulic Power; ATA 30 — 30 — Ice & Rain Protection; ATA 31 — 31 — Indicating / Recording; ATA 32 — 32 — Landing Gear; ATA 33 — 33 — Lights; ATA 34 — 34 — Navigation; ATA 35 — 35 — Oxygen; ATA 36 — 36 — Pneumatics; ATA 38 — 38 — Water & Waste; ATA 45 — 45 — Onboard Maintenance; ATA 47 — 47 — Fuel Tank Inerting; ATA 49 — 49 — APU; ATA 52 — 52 — Doors; ATA 71-80 — 71-80 — RR Trent 700 Engine. ### Boeing 787 (GEnx) *Canonical: https://www.part66online.com/?mod=aircraft&type=8* Practice questions for the Boeing 787 Dreamliner with GE GEnx engines, organised by ATA chapter. Covers the more-electric airframe, the Common Core System, and the GEnx-1B powerplant. Sample questions are free to view; the full timed quiz needs a subscription. The Boeing 787 Dreamliner is a long-range, widebody twinjet and the first Boeing airliner with a more-electric architecture, a composite fuselage, and fly-by-wire flight controls. This question bank follows a 787 type-rating and continuation-training course, organised by ATA chapter so revision maps directly onto the maintenance documentation. Coverage spans the full systems syllabus: the electrical power system and the Common Core System (CCS) computing backbone, communications and navigation, autoflight and thrust management, hydraulics and the flight-control system, fuel, the nitrogen-generation/inert-gas system, fire protection and the APU, air conditioning and pressurisation, ice and rain protection, landing gear, structures, equipment, oxygen, doors and windows. The powerplant chapters address the GE GEnx turbofan — its full-authority digital engine control (FADEC), indicating, ignition and starting, air, oil and exhaust systems. Suitable for initial type-rating preparation or recurrent knowledge checks. ATA chapters covered (34): ATA 05 — 05 — Airplane General & Servicing; ATA 21 — 21 — Air Conditioning & Pressurisation; ATA 22 — 22 — Auto Flight & Thrust Management; ATA 23 — 23 — Communications; ATA 24 — 24 — Electrical Power; ATA 25 — 25 — Equipment & Furnishings; ATA 26 — 26 — Fire Protection; ATA 27 — 27 — Flight Controls; ATA 28 — 28 — Fuel; ATA 29 — 29 — Hydraulic Power; ATA 30 — 30 — Ice & Rain Protection; ATA 31 — 31 — Indicating, Recording & Displays; ATA 32 — 32 — Landing Gear, Wheels & Brakes; ATA 33 — 33 — Lights; ATA 34 — 34 — Navigation; ATA 35 — 35 — Oxygen; ATA 38 — 38 — Water & Waste; ATA 42 — 42 — Common Core System; ATA 44 — 44 — Cabin Systems & IFE; ATA 45 — 45 — Central Maintenance System; ATA 46 — 46 — Information Systems & Networks; ATA 47 — 47 — Inert Gas / Nitrogen Generation; ATA 49 — 49 — APU; ATA 51 — 51 — Structures; ATA 52 — 52 — Doors & Windows; ATA 71 — 71 — Power Plant (GEnx); ATA 72 — 72 — Engine (GEnx); ATA 73 — 73 — Engine Fuel & Control; ATA 74 — 74 — Ignition & Starting; ATA 75 — 75 — Engine Air; ATA 76 — 76 — Engine Controls (FADEC); ATA 77 — 77 — Engine Indicating; ATA 78 — 78 — Exhaust; ATA 79 — 79 — Oil. ## 8. Sample questions with worked answers *Canonical: https://www.part66online.com/sample-quiz/* Below: one sample question per EASA Part66 module and one per aircraft type rating, with the correct answer marked. All questions are drawn from the live PART66Online question bank. ### 1. Mathematics *Question 1245* A car travels 24 miles in 45 minutes. What is its average speed? - A) 18 mph. - B) 32 mph. - C) 36 mph. **Correct answer: B) 32 mph.** ### 2. Physics *Question 285* What is the mass number of an element? - A) Number of electrons and protons. - B) Number of neutrons and protons. - C) Number of protons and electrons. **Correct answer: B) Number of neutrons and protons.** ### 3. Electrical fundamentals *Question 5182* What charge does the nucleus of an atom possess? - A) Positive. - B) Neutral. - C) Negative. **Correct answer: A) Positive.** ### 4. Electronic fundamentals *Question 4824* Which of the following describes the characteristics of a Thyristor? - A) High voltage handling. - B) High power handling. - C) High current handling. **Correct answer: C) High current handling.** ### 5. Digital techniques / Electronic instrument systems *Question 4109* What is the fixed feature of an ADI? - A) The horizon pointer. - B) The aircraft symbol. - C) The pitch scale bars. **Correct answer: B) The aircraft symbol.** ### 6. Materials & hardware *Question 1561* The addition of chromium to steel will produce - A) toughness. - B) hardness. - C) ductility. **Correct answer: B) hardness.** ### 7. Maintenance practices *Question 1796* Acetylene gas forms an explosive compound with - A) tin and silver. - B) tin and copper. - C) copper and silver. **Correct answer: C) copper and silver.** ### 8. Basic aerodynamics *Question 2617* When the pressure is half of that at sea level, what is the altitude? - A) 12,000 ft. - B) 18,000 ft. - C) 8,000 ft. **Correct answer: B) 18,000 ft.** ### 9. Human factors *Question 5* A company's safety policy should be defined in - A) the Air Navigation Order documentation. - B) the approved Maintenance Planning Data. - C) the Maintenance Organization Exposition. **Correct answer: C) the Maintenance Organization Exposition.** ### 10. Aviation legislation *Question 16887* The Chicago Convention of 1944 established which international organisation? - A) The International Civil Aviation Organization (ICAO), responsible for developing global aviation standards - B) The European Union Aviation Safety Agency (EASA), responsible for European aviation regulation - C) The Federal Aviation Administration (FAA), responsible for worldwide aircraft certification **Correct answer: A) The International Civil Aviation Organization (ICAO), responsible for developing global aviation standards** ### 11. Aeroplane aerodynamics, structures and systems *Question 6712* Wing spoilers, when used asymmetrically, are associated with - A) ailerons. - B) elevators. - C) rudder. **Correct answer: A) ailerons.** ### 12. Helicopter aerodynamics, structures and systems *Question 2794* Helicopter rotor blades create lift by - A) pushing the air down. - B) working like a screw. - C) creating low pressure above the blades. **Correct answer: C) creating low pressure above the blades.** ### 13. Aircraft aerodynamics, structures and systems *Question 8023* Pushing the left rudder pedal - A) yaws the aircraft left and possibly the right wing will rise - B) yaws the aircraft left and possibly the left wing will rise - C) yaws the aircraft left but has no effect on the wing **Correct answer: A) yaws the aircraft left and possibly the right wing will rise** ### 14. Propulsion *Question 6862* What is an engine stage? - A) One rotor plus one stator - B) One IGV and one rotor - C) One compressor rotor and one nozzle guide vane **Correct answer: A) One rotor plus one stator** ### 15. Gas turbine engine *Question 2607* A jet engine derives its thrust by - A) drawing air into the compressor. - B) impingement of the propelling gases on the outside air. - C) reaction of the propelling gases. **Correct answer: C) reaction of the propelling gases.** ### 16. Piston engine *Question 11907* In a four-stroke engine, how many crankshaft revolutions are needed to complete one power cycle? - A) Two - B) Six - C) One **Correct answer: A) Two** ### 17. Propeller *Question 1992* The optimum angle for a fixed pitch propeller is - A) 15 degrees. - B) 2 - 4 degrees. - C) 6 - 10 degrees. **Correct answer: B) 2 - 4 degrees.** ### 06 — Dimensions and Areas *Question 20089* What fuselage diameter is shared by all variants of the A320 Family? - A) 4.14 m - B) 3.76 m - C) 3.96 m **Correct answer: C) 3.96 m** ### 24 — Electrical Power (NEO diff) *Question 24540* On the A320neo, how does the electrical distribution system compare with the CEO Enhanced fleet? - A) Uses upgraded solid-state power controllers not found on the CEO - B) Redesigned to cope with the higher bleed-air demands of the new engines - C) Identical to the CEO Enhanced aircraft fleet with no changes to distribution **Correct answer: C) Identical to the CEO Enhanced aircraft fleet with no changes to distribution** ### 00-20 — General / Maintenance Practices *Question 26946* What is the type designator for the A220-100 airframe? - A) BD-500-1A12 - B) BD-500-1A10 - C) BD-500-1A11 **Correct answer: B) BD-500-1A10** ### 01 — Maintenance Documents *Question 31279* How are the FRM and the FIM linked to each other? - A) By a unique 8-digit fault code that identifies each specific fault - B) By a common AMTOSS number system that references tasks across both manuals - C) By the shared ATA chapter and subject numbering used in both documents **Correct answer: B) By a common AMTOSS number system that references tasks across both manuals** ### 00 — 737 General *Question 35662* The LEAP-1B engine is classified as which type? - A) Single rotor, high bypass turbojet - B) Low bypass ratio, twin-spool turboprop - C) High bypass ratio, dual rotor, turbofan **Correct answer: C) High bypass ratio, dual rotor, turbofan** ### 00/51 — Intro & Structures *Question 38857* Which major zone number is assigned to the Nacelles and Pylons on the A330? - A) Zone 500 — Left Wing and control surfaces - B) Zone 300 — Stabilizers and control surfaces - C) Zone 400 — Nacelles and engine pylons **Correct answer: C) Zone 400 — Nacelles and engine pylons** ## 9. How to prepare *Canonical: https://www.part66online.com/* A typical preparation pattern combines: 1. **Read the EASA Part66 syllabus** for each module sat, to understand the depth of knowledge required at each level. 2. **Work through the study notes** topic-by-topic on PART66Online or an equivalent textbook to build foundational understanding. 3. **Practise with the question bank** in timed mode, one module at a time, reviewing wrong answers carefully and re-reading the relevant study notes. 4. **Track weak areas** using the platform's per-topic accuracy analytics and re-attempt those topics until performance is consistently above the 75% pass mark. 5. **Sit a full timed mock exam** at the question count and time limit specified for the target licence category, to confirm readiness. Daily practice of 30–60 minutes over 8–12 weeks per module is a common pattern for candidates working full-time alongside study. ## 10. Pricing and access *Canonical: https://www.part66online.com/subscription/* PART66Online offers a free demo quiz with no account required. Full access to the 43,500+ question bank, timed mode, progress tracking, weak-area analytics, study notes and aircraft type ratings requires a paid subscription. Plans start at EUR 3.75/month; longer-term plans offer lower per-month pricing. Subscription is refundable within the period specified on the Privacy and Refund Policy page. ## 11. UK CAA Part-66 (post-Brexit) *Canonical: https://www.part66online.com/uk-caa-part-66/* After leaving the European Union, the United Kingdom did not abandon Part-66. The UK retained Regulation (EU) No 1321/2014 (whose Annex III is Part-66) into domestic law, with the UK Civil Aviation Authority (CAA) replacing EASA as the issuing authority. The basic-knowledge syllabus was carried over unchanged and the examination standard almost so (the one later difference is the essay modules, noted below), so EASA Part66 study material remains directly applicable to UK CAA Part-66 exam preparation. What is the same between EASA Part66 and UK CAA Part-66: - The 17 basic-knowledge modules and their syllabus (Annex III, Appendix I). - Licence categories A, B1, B2, B2L, B3, C and L. - The 75% pass mark for both multiple-choice and essay questions. - Multiple-choice format: three options, one correct, with no penalty (negative) marking. - The essay-question format and 75% Key-Points marking. Scope divergence since 12 June 2024: EASA Regulation (EU) 2023/989 removed the Module 9 and 10 essays, so the EASA exam now uses essays for Module 7 only, whereas UK CAA still examines Modules 7, 9 and 10 by essay. - The 10-year validity of basic examination passes. What changed after Brexit (licence recognition, not the syllabus): - From 1 January 2021, the EU/EASA no longer recognises UK-issued Part-66 licences. - From 1 January 2023, the UK no longer recognises EASA-issued licences for work on UK-registered aircraft. - The EU-to-UK licence conversion window closed permanently on 31 December 2022. - Maintenance licences are not covered by the UK-EU aviation safety agreement (BASA); there is no automatic mutual recognition. In short: the licences and their recognition diverged, but the knowledge syllabus and exam standard remain aligned. As of 2026 the UK has not diverged the basic-knowledge syllabus, so EASA Part66 question banks are effectively the same for UK CAA Part-66 exam preparation. (Verified June 2026 against UK legislation, the UK CAA and EASA; sources are listed at https://www.part66online.com/uk-caa-part-66/.) ## 12. Part-66 worldwide (recognition beyond the EU) *Canonical: https://www.part66online.com/* Beyond the UK, several civil aviation authorities outside the EU run Part-66-style aircraft maintenance engineer licensing, so EASA Part66 study material is valid preparation for their basic-knowledge (theory) exams. In every case the licences themselves are separate and not mutually recognised with EASA — only the study and exam content aligns. **Australia — CASA (CASR Part 66).** The Civil Aviation Safety Authority built CASR Part 66 and its Manual of Standards in line with the EASA system. CASA's self-study pathway has candidates use commercial Part 66 textbooks and sit exams (through its provider Aspeq) that align to the 17 Part 66 basic-knowledge modules; licence categories are A, B1 (B1.1–B1.4), B2 and C. See https://www.part66online.com/casa-part-66/. **United Arab Emirates — GCAA (CAR-66).** The GCAA CAR-66 (Issue 09) is modelled on EASA Part-66: the same Appendix I basic-knowledge module structure, licence categories A, B1, B2, B3, C and L, an equivalent examination standard and a 10-year validity window. See https://www.part66online.com/uae-part-66/. **Singapore — CAAS (SAR-66).** Singapore's rule is literally named the Singapore Airworthiness Requirements Part 66. Its basic-knowledge exams are module-based (SAR-66 Appendix 1), sat closed book, with a 75% pass mark, and CAAS provides a formal route (Advisory Circular AC-66-10) to convert a foreign Part-66 licence. See https://www.part66online.com/singapore-part-66/. **Hong Kong — CAD (HKAR-66).** Hong Kong's HKAR-66 Aircraft Maintenance Licence (in force since 2002) follows the JAR-66 framework that EASA Part-66 grew out of: the same A, B1, B2, B3, C category structure, the same 75% pass mark and the same module-based written exams. See https://www.part66online.com/hong-kong-part-66/. **India — DGCA (CAR-66).** India modernised its aircraft maintenance engineer licensing with CAR-66 Issue III (in force 12 April 2024), aligned with EASA Part-66 — EASA-style categories (including the newly added B2L and L) and module-based basic-knowledge exams via the DGCA Central Examination Organisation. As this framework is recent, candidates should confirm current DGCA requirements. See https://www.part66online.com/india-part-66/. **Kenya — KCAA (Aircraft Maintenance Engineers' Licence).** The Kenya Civil Aviation Authority's AME Licence Manual (Doc CAA-M-PEL0050, April 2025) is closely modelled on EASA Part-66: the same 17 basic-knowledge modules (Appendix I), the same A, B1, B2, B3, C categories, the same 75% pass mark and the same three-option multiple-choice plus Module 7 essay format (it even mirrors EASA's 66.A.xxx article numbering as KAMEL.A.xxx). An EASA Part-66 training pathway is also delivered inside Kenya. See https://www.part66online.com/kenya-part-66/. **Egypt and Nigeria — EASA Part-66 exam routes delivered locally.** Egypt (ECAA) and Nigeria (NCAA) issue their own national maintenance licences under ICAO-based frameworks rather than EASA Part-66 — Egypt under ECAR Part 65, Nigeria under Nig.CARs Part 2 with Airframe/Powerplant/Avionics ratings. However, a full EASA Part-66 route is available in each: EgyptAir Training is an EASA Part-147 approved organisation (EASA.147.0019) and independent Egyptian schools run EASA Part-66 exams, while in Nigeria EASA and UK-CAA Part-66 module exams are sat through approved training organisations. So EASA Part66 study is valid preparation for the EASA route in both countries and strong grounding for the national exams. See https://www.part66online.com/egypt-part-66/ and https://www.part66online.com/nigeria-part-66/. **United States — FAA (A&P, 14 CFR Part 65).** Unlike the jurisdictions above, the United States does not use Part-66 at all. US mechanics earn an FAA Airframe & Powerplant (A&P) certificate under 14 CFR Part 65, structured as General, Airframe and Powerplant knowledge — three written tests at a 70% pass mark, plus an oral and practical test before a Designated Mechanic Examiner — not the 17 EASA modules, and with no mutual recognition between the two systems. The underlying engineering knowledge overlaps and aircraft type ratings transfer; for FAA A&P test preparation see our sister site amtprep.com. See https://www.part66online.com/faa-a-and-p/. ## 13. EASA Part-145 continuation training (for licensed engineers) *Canonical: https://www.part66online.com/easa-continuation-training/* Beyond exam preparation, PART66Online offers online continuation (recurrent) training for working, licensed aircraft maintenance engineers under EASA Part-145. Four mandatory subjects are covered: - Human Factors (including Safety Management System, SMS) - mapped to AMC and GM to 145.A.30(e) and the safety-management provisions of 145.A.200. https://www.part66online.com/human-factors-training-online/ - Fuel Tank Safety (CDCCL), Phase 2 - mapped to Appendix IV to AMC5 145.A.30(e). https://www.part66online.com/fuel-tank-safety-training/ - EWIS (Electrical Wiring Interconnection Systems), Target Groups 1-2 - mapped to AMC 20-22. https://www.part66online.com/ewis-training-online/ - Information Security (Part-IS) - EASA Part-IS awareness training under Implementing Regulation (EU) 2023/203 (Part-IS.I.OR), applicable to Part-145, CAMO and CAO organisations from 22 February 2026; mapped to the personnel-competence requirement IS.I.OR.240(g) and guidance GM1 IS.I.OR.240(g). https://www.part66online.com/easa-part-is-training-online/ Each subject is offered as an Initial course (the full first-time syllabus) and a Continuation course (the two-year refresher). Every course is a set of taught lessons with knowledge checks and a multiple-choice final examination at a 75% pass mark, and issues a verifiable certificate valid for two years. Human Factors, Fuel Tank Safety and EWIS continuation training under Part-145 is refreshed on a cycle not exceeding two years (points 145.A.30(e) and 145.A.35(d)). Part-IS information security training sets no fixed legal retraining interval: unlike the two-year Human Factors cycle, its refresher frequency is defined by the organisation based on its own risk under guidance GM1 IS.I.OR.240(g), with roughly two years a common industry norm. This training may be delivered by an independent provider: Part-147 approval covers only Part-66 basic and type training and is not required for Human Factors, Fuel Tank Safety, EWIS or Part-IS continuation training. Each course carries a visible syllabus-coverage table cross-referencing every section to its AMC clause; final acceptance of the training rests with the engineer's employing Part-145/CAMO organisation and its competent authority. Pricing: EUR 39.99 per single course, or EUR 99.99 for a three-subject bundle (a "Get Compliant" initial pack or a "2-Year Refresh" continuation pack). Payment is by card. ## 14. Frequently asked questions *Canonical: https://www.part66online.com/* **Q: What is EASA Part66?** Part66 is the European aircraft maintenance licensing regulation — specifically, Annex III of Regulation (EU) No 1321/2014. It defines the categories of Aircraft Maintenance Licence (AML), the modules of theoretical knowledge required for each, and the experience requirements. **Q: What is the pass mark for EASA Part66 module exams?** 75% for all licence categories. **Q: Is EASA Part66 study valid for UK CAA Part-66 exams after Brexit?** Yes. The UK retained the EASA Part66 framework as UK Regulation (EU) No 1321/2014: the same 17 modules, the same licence categories and the same 75% pass mark. Licence recognition between the UK and the EU changed, but the knowledge syllabus and the exams did not, so EASA Part66 question banks apply directly to UK CAA Part-66 preparation. See https://www.part66online.com/uk-caa-part-66/. **Q: Is EASA Part66 study valid outside Europe — in Australia, the UAE, Singapore, Hong Kong, India, Kenya, Egypt or Nigeria?** For the theory exams, largely yes. Australia (CASA CASR Part 66), the UAE (GCAA CAR-66), Singapore (CAAS SAR-66), Hong Kong (CAD HKAR-66), India (DGCA CAR-66) and Kenya (KCAA) all run Part-66-style basic-knowledge module exams, so EASA Part66 question banks are valid preparation. In Egypt and Nigeria the national licence follows a different (ICAO-based) framework, but EASA / UK-CAA Part-66 exams are delivered locally, so EASA study still applies to that route. The licences themselves are separate and not mutually recognised with EASA. Per-country detail is linked from https://www.part66online.com/. **Q: How long does it take to study for a Part66 module?** Depends on the module and the candidate's background. A common pattern is 8 to 12 weeks of daily practice (30–60 minutes) per module for candidates working full-time alongside study. **Q: How many practice questions does PART66Online have?** Over 43,500 multiple-choice questions across the 17 EASA Part66 modules and 7 aircraft type ratings. **Q: Does PART66Online cover aircraft type ratings?** Yes. Seven aircraft type-rating question banks are included: Airbus A320 (Current Engine Option), Airbus A320neo, Airbus A220 (BD500), Boeing 737NG, Boeing 737NG-to-MAX differences, Airbus A320-to-A330 differences, and Boeing 787 (GEnx). Questions are organised by ATA chapter. **Q: Can I try PART66Online before subscribing?** Yes. A publicly accessible demo quiz is available at https://www.part66online.com/sample-quiz/ with no account required. **Q: What is the difference between Category B1 and Category B2?** B1 covers mechanical work (structures, powerplant, mechanical and electrical systems). B2 covers avionic work (autoflight, communications, navigation, instruments and avionic-side electrical). Most aircraft maintenance organisations need both, held by different engineers. **Q: Are there negative marks for wrong answers?** No. The EASA Part66 examination standard (Annex III, Appendix II of Regulation (EU) No 1321/2014) states that penalty (negative) marking shall not be used to determine whether a candidate has passed. Each multiple-choice question has three options with one correct answer, and the pass mark is 75%. **Q: How is PART66Online priced?** Subscription plans start from EUR 3.75/month, with lower per-month pricing on longer-term plans.