EASA Part-66 Exam Preparation Online
Practice with thousands of EASA Part-66 exam questions across all 17 modules, track your progress, and join a community of aviation maintenance engineers preparing for their licence. New to it? Read what EASA Part-66 is — the licence, modules and exams explained.
Every question explained: all 17,000+ EASA Part-66 questions come with a clear, regulation-grounded explanation shown the moment you answer — so you understand why, not just memorise the answer.
All content aligned with the latest Commission Implementing Regulation (EU) 2023/989 — covering categories A, B1, B2, B2L and B3. Also fully applicable to UK CAA Part-66 candidates — the UK keeps the same Part-66 modules, exams and 75% pass mark under UK Regulation (EU) No 1321/2014. UK CAA vs EASA → Valid prep for Australia's CASA Part 66 self-study exams too. CASA vs EASA →
Part-66 worldwide: the same module-based study also prepares you for Part-66-aligned exams in the UAE (GCAA CAR-66), Qatar (QCAR Part-66), Singapore (SAR-66), Hong Kong (HKAR-66) and India (DGCA CAR-66) and Kenya (KCAA), plus where EASA / UK-CAA Part-66 exams are sat locally in Egypt (ECAA) and Nigeria (NCAA).
Aircraft Type Training: practice question banks for the Airbus A320 (CEO & NEO), A220 and A330 and Boeing 737NG, 737 MAX and 787, organised by ATA chapter with worked answers and timed practice.
Fact of the Day
5. Digital techniques / Electronic instrument systemsDe Morgan's Theorem: NOT(A AND B) = (NOT A) OR (NOT B), and NOT(A OR B) = (NOT A) AND (NOT B) — why NAND and NOR are universal.
Study Modules
1. Mathematics
1062 questions
2. Physics
998 questions
3. Electrical fundamentals
1242 questions
4. Electronic fundamentals
876 questions
5. Digital techniques / Electronic instrument systems
1094 questions
6. Materials & hardware
1209 questions
7. Maintenance practices
1391 questions
8. Basic aerodynamics
1120 questions
9. Human factors
746 questions
10. Aviation legislation
500 questions
11. Aeroplane aerodynamics, structures and systems
2137 questions
12. Helicopter aerodynamics, structures and systems
1279 questions
13. Aircraft aerodynamics, structures and systems
955 questions
14. Propulsion
660 questions
15. Gas turbine engine
1377 questions
16. Piston engine
500 questions
17. Propeller
802 questions
Module 1
Mathematics
6 articles
Module 2
Physics
8 articles
Module 3
Electrical Fundamentals
18 articles
Module 4
Electronic Fundamentals
5 articles
Module 5
Digital Techniques / Electronic Instrument Systems
15 articles
Module 6
Materials and Hardware
16 articles
Module 7
Maintenance Practices
27 articles
Module 8
Basic Aerodynamics
4 articles
Module 9
Human Factors
10 articles
Module 10
Aviation Legislation
10 articles
Module 11
Aeroplane Aerodynamics, Structures and Systems
54 articles
Module 12
Helicopter Aerodynamics, Structures and Systems
22 articles
Module 13
Aircraft Aerodynamics, Structures and Systems
46 articles
Module 14
Propulsion
8 articles
Module 15
Gas Turbine Engine
22 articles
Module 16
Piston Engine
16 articles
Module 17
Propeller
7 articles
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900+ pages, 17 modules, lifetime access. First paragraph of each module is free to preview.
EASA Part-145 Continuation Training
For licensed engineers — the mandatory 2-year safety training (Human Factors, Fuel Tank Safety, EWIS), certificated and mapped to the AMC.
"Get Compliant" - Initial Pack
Get first-time compliant on all three mandatory subjects
- Human Factors (incl. SMS) — Initial
- Fuel Tank Safety (CDCCL) — Initial
- EWIS (Target Groups 1-2) — Initial
"2-Year Refresh" - Continuation Pack
The 2-year refresh for all three mandatory subjects
- Human Factors (incl. SMS) — Continuation
- Fuel Tank Safety (CDCCL) — Continuation
- EWIS (Target Groups 1-2) — Continuation
Aircraft Type Training
Airbus A320 - CEO
43 ATA chapters · 4,451 questions
Airbus A320 - NEO
24 ATA chapters · 2,406 questions
Airbus A220 (BD500)
42 ATA chapters · 4,332 questions
Boeing 737NG
27 ATA chapters · 4,384 questions
Boeing 737NG to MAX Diff
30 ATA chapters · 3,194 questions
Airbus A320 to A330 Diff
23 ATA chapters · 2,392 questions
Boeing 787 (GEnx)
34 ATA chapters · 4,423 questions
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Recent Q&A Activity
Actually, C is correct for the general case, since a low blade angle presents the least air load and lets the engine accelerate to idle with minimum starter effort. On the PT6 the propeller is a free-turbine layout decoupled from the starter, and on most reversing installations it rests on the fine-pitch start locks rather than in feather, so C still applies.
svenj88 replied to JayACA's question ·11h ago
The PT6 starts with the blades in feather?
JayACA asked a question ·12h ago
Hello. Indeed, moved to module 2.
PART66Online replied to Tj Anderson's question ·5d ago
why is this here (coming from CASA system) this is a buit random
Tj Anderson asked a question ·5d ago
A. High fidelity means low distortion, Class A is most linear, Class C is efficient for RF but distorts too much for clean audio.
Marek_AME replied to udreacc's question ·15d ago
Why else would the cockpit indicator run off it as a synchronous motor if the tacho was not making AC? The aircraft tachogenerator is a 3 phase permanent magnet unit, so the output is a sinusoidal AC voltage whose frequency tracks the rpm, that is why it is sinusoidal even though the stem never says AC. Linear only describes voltage against speed, not the waveform, so it does not apply here.
carlosmd replied to udreacc's question ·15d ago
Class C is specially designed for RF and only that and can't be used for audio
udreacc asked a question ·15d ago
in the question it is not mentioned it is referring to AC
udreacc asked a question ·15d ago
B. You are right, question does not say series or parallel, marked answer fits the series case where XL and XC cancel and only resistor remains, in parallel it would be maximum instead.
Marek_AME replied to Wesley 's question ·22d ago
The question does not say if the LCR circuit is in series or parallel. Series RLC at resonance: XL and XC cancel, leaving only R. Impedance = low (just R, could be very low if R is small). Parallel RLC at resonance: XL and XC still cancel in terms of reactance, but because the components are in parallel, this results in high impedance — approaching infinite in the ideal case
Wesley asked a question ·22d ago