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EASA Part-66 Module 11 Cats A1 · A2 · B1.1 · B1.2 · B3

Aeroplane Aerodynamics, Structures and Systems EASA Part-66 — Module 11 Practice Questions

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.

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Every question comes with a worked, EASA-grounded explanation — understand why, don't just memorise.
2 137
Questions in bank
5
Syllabus sections
175 min
Exam time (B1/B2)
75 %
EASA pass mark

Syllabus at a glance

Full Module 11 syllabus
Section 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+)
Section 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
Section 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
Section 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
Section 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)

Three classic exam-day traps

Stall speed in a banked turn

Stall speed scales with the square root of load factor, not the bank angle directly. At 60° bank the load factor is 2g, so stall speed multiplies by √2 ≈ 1.41, not 2.

Phosphate-ester seals vs Skydrol myth

Phosphate-ester fluids (Skydrol, HyJet) attack natural rubber and most synthetic rubbers. Only butyl rubber, ethylene-propylene or PTFE/Teflon seals are compatible — a fluid-and-seal pairing the exam repeatedly tests.

Cabin pressure controller — outflow, not inflow

The cabin pressure controller regulates the outflow valve position. Air supply mass-flow into the cabin is essentially constant; cabin altitude is set by how much air is allowed out.

What Module 11 covers — in plain English

Module 11 is the largest module in the EASA Part-66 syllabus and the heart of any aeroplane-rated licence. It pulls together everything an aircraft maintenance engineer needs to know about how an aeroplane flies and how its on-board systems work — from the aerodynamic theory behind lift and stall, through airframe construction philosophies, to every major ATA chapter: hydraulics, landing gear, flight controls, electrical power, pneumatics, fuel, ice protection, oxygen, instruments and avionics. If a system is mentioned in a typical line-maintenance task card, it is almost certainly examined in Module 11.

The exam scales with licence category, and Module 11 has the longest paper of any module. Category A1 candidates sit 108 questions in 135 minutes; A2 sits 72 in 90 minutes; B1.1 candidates face 140 questions in 175 minutes, B1.2 sits 100 in 125 minutes, and B3 sits 60 in 75 minutes. There is no Category B2 paper for Module 11 — B2 avionics candidates sit Module 13 instead, although the underlying aircraft-system content overlaps heavily. The syllabus itself is split into two big halves: aerodynamics and structures (sections 11.1 to 11.3) and aircraft systems organised by ATA chapter (sections 11.4 to 11.21). The second half is where the bulk of the question bank lives, because each chapter mirrors a real on-aircraft system you will work on every day in the hangar.

Knowledge levels jump sharply for B1 candidates compared with Cat A. Most system chapters sit at level 3 for B1, meaning you need to understand detailed theory of operation, be able to troubleshoot, and apply principles to real fault scenarios — not just recognise components. Category A and B3 candidates mostly sit those same chapters at level 1 or 2, so the same question bank serves several licence tracks with very different depth expectations. Reading the knowledge-level table carefully before you study is the single best use of an hour: it tells you which chapters need rote learning and which need real comprehension.

Common Module 11 pitfalls cluster around three areas. First, aerodynamic relationships that look intuitive but aren’t — stall speed scales with the square root of load factor, not load factor itself, and the centre of pressure moves aft as a subsonic aircraft accelerates, not forward. Second, material and fluid compatibility — phosphate-ester hydraulic fluid attacks most rubbers, while titanium near phosphate-ester contamination becomes brittle. Third, control-logic questions where candidates confuse cause and effect — assuming a cabin pressure controller varies inlet flow rather than outflow, for example. The full per-section knowledge-level breakdown for each licence category is on our Module 11 syllabus page.

These samples are drawn from our live Module 11 question bank of 2 137 questions. The full timed practice quiz draws 140 questions per attempt (or 108 for Cat A), scored against the official EASA 75 % pass mark, with weak-area tracking across attempts.

7 free sample questions

Click "Reveal answer + explanation" after you've picked.

Take the timed practice quiz
Q1 Theory of Flight · Stall

The stall speed in a 60 degrees banked turn increases by the following factor:

  1. A 1.
  2. B 1.41.
  3. C 2.00.
Reveal answer + explanation Hide answer
Correct answer: B1.41.
Load factor in a level turn = 1 / cos(bank). At 60°, cos = 0.5, so load factor = 2g. Stall speed scales with √n, giving √2 ≈ 1.41. Picking 2.00 is the classic trap — that would be the load factor, not the stall-speed multiplier.
Q2 Theory of Flight · High-Speed Flight

As the airspeed over a cambered wing is increased, a shock wave will appear initially

  1. A near the point of maximum curvature.
  2. B at the leading edge.
  3. C at the trailing edge.
Reveal answer + explanation Hide answer
Correct answer: Anear the point of maximum curvature.
Local airflow accelerates fastest over the point of maximum camber, so it reaches sonic velocity there first as free-stream Mach approaches the critical value. The first shock wave therefore forms near maximum curvature, then moves aft as Mach increases.
Q3 Airframe Structures · Fuselage

What opposes buckling in a semi-monocoque structure?

  1. A Stringers
  2. B Bulkheads
  3. C Frames
Reveal answer + explanation Hide answer
Correct answer: AStringers
In a semi-monocoque fuselage, stringers run longitudinally along the inside of the skin and resist axial compression and skin buckling. Frames and bulkheads give the fuselage its cross-sectional shape and carry hoop loads, but they do not directly oppose buckling.
Q4 Hydraulics · Fluids & Seals

Phosphate Ester hydraulic fluid requires which kind of seals?

  1. A Butyl Rubber.
  2. B Natural Rubber.
  3. C Synthetic Rubber.
Reveal answer + explanation Hide answer
Correct answer: AButyl Rubber.
Phosphate-ester fluids (Skydrol, HyJet) chemically attack natural and most synthetic rubbers, swelling them and destroying seal integrity. Compatible elastomers are butyl rubber, ethylene-propylene (EPDM) or PTFE/Teflon. Mineral-oil systems use the opposite seals — fluid/seal compatibility is a frequent Module 11 pitfall.
Q5 Pressurisation · Cabin Pressure Control

Cabin pressure controller maintains a particular cabin altitude by control of

  1. A cabin mass air flow.
  2. B inward relief valve position.
  3. C outflow valve position.
Reveal answer + explanation Hide answer
Correct answer: Coutflow valve position.
Bleed-air supply into the cabin is essentially constant. The controller sets cabin altitude by modulating the outflow valve — open it more and pressure drops, close it and pressure rises. The inward relief valve only opens to prevent negative differential during a rapid descent.
Q6 Electrical Power · Battery

If the battery is switched off in flight, the

  1. A battery is disconnected from bus.
  2. B captain's instruments will be powered from the standby bus.
  3. C generator voltage falls to zero.
Reveal answer + explanation Hide answer
Correct answer: Abattery is disconnected from bus.
The battery master switch operates the battery relay/contactor — switching it off simply disconnects the battery from the busbar. Generators continue to feed the main buses normally, and instrument power is unaffected as long as generator output remains available.
Q7 Instruments · Pitot-Static

What instrument connects to pitot pressure?

  1. A Both the airspeed indicator and the vertical speed indicator.
  2. B The vertical speed indicator.
  3. C The airspeed indicator.
Reveal answer + explanation Hide answer
Correct answer: CThe airspeed indicator.
Only the airspeed indicator uses pitot (ram) pressure — it compares pitot against static to derive dynamic pressure. The altimeter and VSI use static pressure only. Confusing which instruments tap which line is a textbook pitot-static troubleshooting trap.
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Ready for the full Module 11 timed practice quiz?

Sign up, pick Module 11 from the dashboard, and take a timed exam drawn from our 2 137-question bank — the number of questions follows your licence category (108 for Cat A, 140 for B1/B2/B2L/B3). Your score is tracked across attempts and we surface your weakest sub-topics so revision time pays off.

Module 11 — frequently asked questions

How many questions are in the EASA Part-66 Module 11 exam?
The number of questions scales with licence category. Category A candidates sit 108 multiple-choice questions, while Category B1 candidates sit 140 multiple-choice questions — reflecting the deeper knowledge level B1 engineers are held to. Module 11 has the longest paper of any module in the syllabus, so pacing yourself is essential.
What is the pass mark for EASA Part-66 Module 11?
The pass mark is 75%, the same as every EASA Part-66 module. You must answer at least 75% of the questions correctly to pass, so on the 140-question Category B1 paper that means roughly 105 correct answers. Practising a large mixed question bank is the most reliable way to reach that threshold consistently.
How long is the Module 11 exam?
Category A candidates are given 135 minutes for their 108 questions, and Category B1 candidates are given 175 minutes for their 140 questions. That works out to roughly 75 seconds per question, so time management across this large syllabus is important — flag the tricky ones and come back rather than getting stuck.
Which EASA licence categories require Module 11?
Module 11 is required for Cats A1, A2, B1.1, B1.2 and B3 — the aeroplane maintenance categories. It is not part of the avionics (B2) track, which instead sits Module 13 for aircraft systems, although the underlying content overlaps heavily. Because Module 11 is aeroplane-specific, helicopter categories (B1.3/B1.4) take Module 12 in its place.
What does Module 11 cover, and what do students find hardest?
Module 11 is the largest module in the syllabus, spanning theory of flight, airframe structures, and every major aircraft system by ATA chapter — hydraulics and landing gear, air and fuel systems, pressurisation, ice protection, electrical power and avionics. Students most often stumble on relationships that look intuitive but are not: stall speed scales with the square root of load factor, so a 60° banked turn (2g) raises it by √2 ≈ 1.41, not 2. Fluid-and-seal compatibility is another repeat trap — phosphate-ester fluids attack natural and most synthetic rubbers, so only butyl rubber, EPDM or PTFE seals are compatible. Control-logic questions catch people out too, such as the cabin pressure controller regulating the outflow valve, not the air supplied into the cabin.
How should I revise for Module 11?
Because Module 11 bundles 20+ sub-sections, work through it one system group at a time rather than trying to absorb the whole syllabus at once — theory of flight and structures first, then the ATA-chapter systems. Pay particular attention to the recurring trap areas: aerodynamic relationships (stall speed vs load factor), fluid and material compatibility, and cause-and-effect in system control logic. Drilling large sets of practice questions across all the chapters is the best way to build both recall and the pacing you need for the longest paper in the syllabus.

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