EASA Part-66 Airframe Exam FAQ: Modules 11, 12 & 13
Airframe knowledge is examined through the EASA Part-66 module system: Module 11 for aeroplane B1 candidates, Module 12 for helicopter B1 candidates, and Module 13 for B2 avionics candidates, supported by Module 6 (Materials and Hardware) and Module 7 (Maintenance Practices). This FAQ answers the most common questions about module content, exam format, difficulty, and how to prepare effectively with Skylicence Europe.
Skylicence Europe Team
EASA Part-66 exam preparation specialists — helping engineers earn their Part-66 licence since 2025
Overview of the EASA Part-66 Airframe Modules
The airframe modules are the technical core of the EASA Part-66 aircraft maintenance licence, defined in Annex III to Regulation (EU) No 1321/2014. Module 11 (Aeroplane Aerodynamics, Structures and Systems) is required for B1.1 (aeroplane turbine) and B1.2 (aeroplane piston) candidates, Module 12 for helicopter categories B1.3 and B1.4, and Module 13 for B2 (avionics) candidates who need systems-level knowledge of the airframe. The syllabuses in Part-66 Appendix I define the depth level required for each subject — levels 1 (overview), 2 (detailed) and 3 (in-depth) — with B category licences requiring the deeper levels.
The module exams ensure that every licence applicant has a comprehensive understanding of how airframe systems work, how they are maintained, and how to diagnose and correct faults. While your practical experience develops hands-on skills, the exams verify the theoretical foundation needed to make sound maintenance decisions. Questions range from basic component identification and function to complex integrated scenarios where a failure in one system affects the operation of another — exactly the kind of reasoning required for real-world troubleshooting.
Preparing for the airframe modules requires a systematic approach. With so many subject areas, you cannot afford to study randomly. The most successful candidates organise study by system, master each system individually, and then practise with cross-system scenarios. Skylicence Europe supports this approach with subject-based adaptive difficulty — as you demonstrate proficiency in one area, the platform progresses you to harder questions while mixing in questions from previously mastered subjects to reinforce retention. This spiral learning approach keeps material fresh throughout your study period.
Key Airframe Subject Areas to Master
Certain subject areas receive more emphasis on the module exams. Hydraulic and pneumatic power systems are consistently among the most heavily tested topics, followed by landing gear systems and aircraft structures. Flight controls and rigging, fuel systems, and cabin atmosphere control form the next tier. Inspection requirements — including the use of the AMM, the structural repair manual, and approved maintenance data — appear across all subject areas. Allocate your study time accordingly, spending more time on high-weight topics while still covering every subject in the Part-66 Appendix I syllabus. Skylicence Europe performance analytics show your accuracy by subject so you can see where you stand relative to the exam requirements.
Frequently Asked Questions
What is the EASA Part-66 airframe content and which modules cover it?
Under Regulation (EU) No 1321/2014, Annex III (Part-66), airframe knowledge is examined through the module system defined in Appendix I. For B1.1 and B1.2 (aeroplane) licence applicants, airframe structures and systems are covered by Module 11 (Aeroplane Aerodynamics, Structures and Systems); for B1.3 and B1.4 (helicopter) applicants, Module 12 (Helicopter Aerodynamics, Structures and Systems) replaces it; and for B2 (avionics) applicants, Module 13 (Aircraft Aerodynamics, Structures and Systems) covers the systems knowledge. Supporting modules include M6 (Materials and Hardware) and M7 (Maintenance Practices), which every candidate must pass. Skylicence Europe aligns its airframe question bank to the Part-66 Appendix I syllabuses so you study exactly what the module exams test.
How many questions are on the airframe module exams and how much time do I get?
Each Part-66 module has a set question quota and time limit. For airframe content: Module 11 has 120 questions in 150 minutes, Module 12 has 90 questions in 115 minutes, and Module 13 has 120 questions in 150 minutes. The pass mark for every module exam is 75 percent (66.A.25), meaning you must answer at least 90 of the 120 Module 11 questions correctly. Module exams are computer-based and administered by approved maintenance training organisations (MTOs). Skylicence Europe offers timed mock exams that replicate the exact quota and duration of each airframe module so you can build both speed and accuracy before exam day.
What are the most important topics to study for the airframe module exams?
For Module 11, the highest-weight subject areas are: aeroplane aerodynamics and flight controls; airframe structures — fuselage, wings, stabilisers, and landing gear attachments; hydraulic power systems with pumps, actuators, valves, accumulators, and fluids; landing gear including shock struts, retraction mechanisms, wheels, brakes, and anti-skid; cabin atmosphere control and pressurisation; fuel systems; and ice and rain protection. Module 6 adds the materials side — ferrous and non-ferrous metals, composites, corrosion types, and fasteners — while Module 7 covers maintenance practices such as inspection techniques and documentation. Skylicence Europe performance analytics show your accuracy by module subject area so you can see exactly where you stand.
Is the airframe content harder than the engine (propulsion) content?
Opinions vary among licensed engineers, but many find the airframe modules slightly more challenging because they span a broader range of systems. Module 11 draws from roughly two dozen subject areas covering everything from structural materials to complex hydraulic and environmental systems, while the propulsion modules (M14, M15, M16, M17) focus more narrowly on engines and their supporting systems. However, if you have strong hands-on experience with airframe systems, you may find the airframe material more intuitive. Both areas are required for the B1 licence, so a balanced study plan is essential. Skylicence Europe tracks your accuracy across each module subject area so you can identify and fix weak spots before exam day.
Do I need to know specific aircraft types for the airframe module exams?
The Part-66 module exams evaluate general airframe knowledge that applies across aircraft types, not model-specific details. You will not be asked about the landing gear configuration of a Boeing 737 versus an Airbus A320. Instead, the exams cover airframe principles that apply broadly: how hydraulic systems work, what materials are used for different structural components, the principles of flight control actuation, and inspection criteria from the applicable maintenance data. You should, however, be familiar with representative examples from general aviation, transport-category, and rotorcraft to answer scenario-based questions. Skylicence Europe questions use these representative examples to help you connect principles to real aircraft.
What types of hydraulic systems are covered in Module 11?
Hydraulic power systems are one of the most heavily tested airframe topics. You need to understand basic hydraulic principles (Pascal law, pressure, flow, force multiplication), hydraulic fluid types (mineral-based, phosphate ester such as Skydrol, and their compatibility), system components — pumps (gear, vane, piston), actuators, selector valves, pressure relief valves, check valves, sequence valves, accumulators, filters, and reservoirs — and system operation including power-up, pressure regulation, and emergency systems. You should also know how to identify fluid contamination, proper handling procedures, and the dangers of mixing incompatible fluids. Skylicence Europe includes a dedicated hydraulics section with progressive difficulty aligned to the Module 11 syllabus.
How much materials and metallurgy knowledge do I need?
The airframe path requires a solid understanding of aircraft structural materials, tested mainly through Module 6 (Materials and Hardware). You should know the common aluminium alloys used in airframe construction (2024, 6061, 7075) and their characteristics — strength, corrosion resistance, and typical applications. You should understand heat treatment processes (solution heat treatment, precipitation hardening, annealing) and how they affect material properties. Steel alloys such as 4130 and 4340 and their use in landing gear and engine mounts are also tested. Composite materials — fibreglass, carbon fibre, and Kevlar — are increasingly covered as they become more common in modern aircraft. Knowledge of corrosion types (surface, pitting, intergranular, exfoliation, stress corrosion cracking) and their detection and treatment is essential.
What should I know about landing gear systems?
Landing gear is a major topic area in the airframe modules. You need to understand landing gear configurations (conventional, tricycle, tandem) and fixed versus retractable arrangements. Key components include shock struts (oleo-pneumatic, spring, bungee), retraction and extension mechanisms (hydraulic, electric, and manual backup), wheel and brake assemblies (disc brakes, expander tube brakes, anti-skid systems), nose wheel steering, and landing gear position and warning systems. Tyre construction, ratings, and wear limits are also tested, along with inspection criteria for landing gear components. Know the difference between servicing checks and the inspection requirements described in the aircraft maintenance manual (AMM) and the maintenance organisation procedures.
How are flight control systems tested?
Flight control questions test your knowledge of primary flight controls (ailerons, elevators, rudder) and secondary flight controls (flaps, slats, spoilers, trim tabs, servo tabs). You should understand actuation methods — mechanical cables, push-pull rods, hydraulic actuators, and fly-by-wire — control surface construction, balancing and rigging requirements, and the effects of control surface defects. Trim systems, including trim tabs, balance tabs, anti-servo tabs, and electric trim, are frequently tested. You should also know inspection requirements for control cables (wear limits, tension, corrosion), pulleys, and fairleads. Rigging and travel-limit checks referenced in the airframe manuals and the AMM are common question sources.
What study strategy works best for the EASA Part-66 airframe modules?
The most effective strategy combines topical study with system-level integration. Start by studying each airframe system individually — hydraulics, landing gear, flight controls, structures, fuel, pneumatics, and environmental systems — using focused question sets. Once you have solid knowledge of each system, practise with integrated scenario questions that require combining knowledge across multiple systems, such as a hydraulic failure affecting landing gear extension and flight control operation. Use the Part-66 Appendix I syllabus as your checklist and approved training material as your primary reference. Skylicence Europe supports this with subject-level adaptive difficulty for initial learning and mixed-topic mock exams for integration practice.
Do I need to pass other modules before the airframe modules?
There is no required order for Part-66 module exams. You can take them in any sequence that suits your schedule, and each module certificate is issued independently by the maintenance training organisation after you pass the exam. Many candidates take the foundation modules first — M1 Mathematics, M2 Physics, M3 Electrical Fundamentals — because their content underpins the technical modules. Before you can be issued a licence, you must pass all modules applicable to your category, complete the practical experience required by 66.A.30 (documented in a logbook and supervised by certifying staff), and demonstrate competency in the associated practical assessments. Module certificates issued by an MTO are a key part of that evidence trail.
How does Skylicence Europe prepare me for the EASA Part-66 airframe modules?
Skylicence Europe offers 4,464 EASA Part-66 practice questions across all 17 modules, with dedicated airframe coverage for Modules 6, 7, 11, 12 and 13. Features include AI-powered adaptive difficulty that adjusts to your performance across each topic area, detailed answer explanations, timed mock exams that match the real question quotas and time limits, and performance analytics showing your accuracy by module subject. Whether you are studying structures, hydraulics, landing gear, or flight controls, Skylicence Europe adapts to your level and focuses you on the areas that need work. One licence category is free on the FREE plan — start practising today.
For more on the EASA Part-66 licence and the other module exams, check out our complete EASA Part-66 study guide and the powerplant module exam FAQ. Visit the main Skylicence Europe FAQ for platform questions.
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