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100+ Free EASA Module 17 Practice Questions

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Key Facts: EASA Module 17 Exam

32 questions

B1.1/B1.2/B3 Exam Length

EASA Part-66 Appendix II

40 minutes

Time Allowed (B1)

EASA Part-66

75%

Pass Mark

EASA Part-66 Appendix II

80-90 degrees

Feather Blade Angle

Propeller theory

12 June 2024

17A/17B Merged Into Module 17

Regulation (EU) 2023/989

12 June 2026

Old-Standard Course Deadline

Regulation (EU) 2023/989

EASA Part-66 Module 17 (Propeller) is a basic knowledge module for the European aircraft maintenance licence, required for B1.1, B1.2, B3, A1 and A2 mechanics. For B1.1/B1.2/B3 the exam is 32 three-option multiple-choice questions in 40 minutes with a 75% pass mark and no negative marking (A1/A2 sit 20 questions in 25 minutes). The syllabus covers fundamentals (blade element theory, geometric versus effective pitch, slip, blade angle and angle of attack, centrifugal/aerodynamic/thrust forces, twisting moments, torque and P-factor); construction (wood, metal and composite blades, hubs, classification of fixed, controllable and constant-speed propellers); pitch control (constant-speed units, governors, speed-control range, feathering, reverse pitch, overspeed protection); synchronising and synchrophasing; fluid and electrical ice protection; and maintenance (static and dynamic balancing, blade tracking, damage assessment, repair classification, tachometer checks, storage). Under Regulation (EU) 2023/989, applicable 12 June 2024, the former 17A and 17B sub-modules were merged into a single Module 17; pre-2024 courses must finish under the old standard by 12 June 2026.

Sample EASA Module 17 Practice Questions

Try these sample questions to test your EASA Module 17 exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1In propeller blade element theory, the blade is analysed as a series of small aerofoil sections along its length. Why is the geometric pitch (blade angle) progressively reduced from the root to the tip?
A.Because the tip moves through a greater rotational distance per revolution than the root, so a smaller angle keeps the angle of attack and advance roughly constant along the blade
B.Because the root sees a higher relative airflow velocity than the tip and must be unloaded
C.Because centrifugal force is greatest at the tip and a small angle reduces blade stress
D.Because the tip operates in compressible flow and a small angle prevents shock formation at all speeds
Explanation: Each blade section advances forward the same distance per revolution but the tip travels a much larger circumferential distance, giving it a higher rotational speed and a shallower helix angle; the blade is therefore 'twisted' with a smaller geometric angle at the tip so each section meets the relative airflow at an efficient angle of attack.
2Propeller geometric pitch is defined as the distance the propeller would advance in one revolution if it moved through the air like a screw through a solid. The actual distance the propeller advances is the effective pitch. The difference between geometric and effective pitch is known as:
A.Slip
B.Blade angle
C.Helix angle
D.Angle of attack
Explanation: Slip is the difference between geometric pitch (theoretical advance) and effective pitch (actual advance) and arises because air is a fluid the blade can push backwards rather than a solid; it is usually expressed as a percentage of geometric pitch.
3For a fixed-pitch propeller, what happens to the angle of attack of the blade sections as the aircraft's forward (true) airspeed increases at a constant engine RPM?
A.The angle of attack increases because the relative airflow becomes more axial
B.The angle of attack remains constant because RPM is unchanged
C.The angle of attack decreases because the forward velocity vector increases the helix angle of the relative airflow
D.The angle of attack reverses, producing negative thrust
Explanation: The relative airflow at each blade section is the resultant of the rotational velocity and the forward (advance) velocity. As forward speed rises with RPM fixed, the advance component grows, the helix angle of the resultant airflow increases, and because the blade angle is fixed the angle of attack falls - reducing thrust at high speed.
4Which force acting on a rotating propeller blade is by far the greatest in magnitude and acts to throw the blade outward along its longitudinal axis?
A.Thrust bending force
B.Centrifugal twisting moment
C.Centrifugal force
D.Aerodynamic twisting moment
Explanation: Centrifugal force, caused by rotation, is the largest single load on a propeller blade and tries to pull each blade radially outward from the hub; it can reach many tonnes of pull at the blade root and dominates blade and retention design.
5The centrifugal twisting moment (CTM) acting on a rotating propeller blade tends to rotate the blade toward which pitch position, and how is this exploited in many propeller designs?
A.Toward low (fine) pitch; used to drive the blades to fine pitch on oil-pressure loss
B.Toward high (coarse) pitch; used to assist feathering
C.Toward feather; used as an overspeed stop
D.Toward reverse; used to assist ground braking
Explanation: The centrifugal twisting moment always tries to rotate the blade toward the plane of rotation, i.e. toward low (fine) pitch. Single-engine constant-speed propellers use this natural tendency, often with a spring, so that on loss of governing oil pressure the blades go to fine pitch (high RPM) as a fail-safe.
6The aerodynamic twisting moment (ATM) on a propeller blade in normal forward thrust acts to rotate the blade toward:
A.Low (fine) pitch
B.High (coarse) pitch
C.The reverse pitch stop
D.The plane of rotation
Explanation: The aerodynamic twisting moment results from the centre of pressure of the blade aerofoil being forward of the blade's pitch-change axis; this tends to rotate the blade toward high (coarse) pitch. It is smaller than the centrifugal twisting moment, which opposes it toward fine pitch.
7P-factor (asymmetric blade effect) on a single-engine aircraft at high power and high angle of attack causes the propeller's resultant thrust line to move. For a conventional clockwise-rotating propeller (viewed from behind), the descending blade is on the right side and the aircraft yaws:
A.To the left, because the descending right blade produces more thrust
B.To the right, because the descending right blade produces more thrust
C.To the right, because the ascending left blade produces more thrust
D.There is no yaw because thrust remains symmetric
Explanation: At a high angle of attack the descending (down-going) blade meets the relative airflow at a greater effective angle of attack and higher resultant velocity, producing more thrust than the up-going blade. For a clockwise propeller the descending blade is on the right, so the extra thrust on the right yaws the nose left.
8Propeller torque reaction tends to roll the aircraft in which direction, and why?
A.In the opposite direction to propeller rotation, as a Newton's third-law reaction to the torque driving the propeller
B.In the same direction as propeller rotation, because of conservation of momentum
C.Toward the descending blade, because of asymmetric thrust
D.It produces a pitching moment, not a rolling moment
Explanation: By Newton's third law, the engine torque that spins the propeller produces an equal and opposite reaction on the airframe. A propeller turning clockwise (viewed from behind) therefore produces a torque reaction that tends to roll the aircraft to the left (anticlockwise).
9On takeoff, to convert the maximum available engine power into thrust, a constant-speed propeller is set to:
A.High RPM and a low (fine) blade angle
B.Low RPM and a high (coarse) blade angle
C.High RPM and a high (coarse) blade angle
D.Low RPM and a low (fine) blade angle
Explanation: For takeoff the propeller control is set fully forward to give maximum (high) RPM, which the governor holds with a low (fine) blade angle. Low forward speed and high RPM keep the blade sections at an efficient angle of attack, maximising thrust for the climb.
10A propeller blade section is identified by reference points. The portion of the blade that mates with the hub is the root or shank; the leading-edge side that faces forward in flight is the:
A.Blade face (the cambered side toward the cockpit)
B.Blade back (the cambered, lower-pressure side toward the front)
C.Blade station
D.Blade shank fairing
Explanation: The blade back is the cambered (curved) side that faces the direction of flight and develops lower pressure, analogous to the upper surface of a wing; the blade face is the flatter side facing aft toward the pilot. The pressure difference between back and face generates thrust.

About the EASA Module 17 Exam

EASA Part-66 Module 17 (Propeller) is one of the basic knowledge modules of the European aircraft maintenance licence and is required for the B1.1, B1.2, B3, A1 and A2 categories. It covers propeller fundamentals, construction, pitch control and the constant-speed unit, feathering and reverse pitch, synchronising and ice protection, and propeller maintenance and storage. The module is examined by 3-option multiple-choice questions with a 75% pass mark. Under Commission Implementing Regulation (EU) 2023/989 (applicable 12 June 2024) the former sub-modules 17A and 17B were merged into a single Module 17.

Questions

32 scored questions

Time Limit

40 minutes (B1.1/B1.2/B3); 25 minutes for A1/A2

Passing Score

75% per module

Exam Fee

Varies by NAA/Part-147 organisation (approximately EUR 50-230 per module sitting) (EASA framework - examinations conducted by National Aviation Authorities or approved Part-147 maintenance training organisations)

EASA Module 17 Exam Content Outline

24%

Propeller Fundamentals

Blade element theory, geometric and effective pitch, slip, blade angle and angle of attack, high/low/reverse angle, aerodynamic, centrifugal and thrust forces, centrifugal and aerodynamic twisting moments, torque reaction, P-factor, tip speed, vibration and resonance

16%

Propeller Construction

Wooden, aluminium-alloy and composite blades, blade nomenclature (face, back, shank, root, station), cuffs, hub assembly, activity factor, and classification of fixed-pitch, controllable-pitch and constant-speed propellers

24%

Pitch Control, CSU and Governor

Constant-speed units and governors (speeder spring, flyweights, pilot valve, gear pump), on-speed/over-speed/under-speed governing, speed-control range and pitch stops, oil pressure direction, overspeed protection, and cam/hydromatic pitch-change mechanisms

14%

Feathering and Reverse Pitch

Feathering springs, counterweights, anti-feather latches, feathering pumps and unfeathering accumulators, negative-torque sensing, beta range, beta tube feedback, reverse (negative) pitch and flight-idle stops

10%

Synchronising and Ice Protection

Propeller synchronising and synchrophasing (master/slave, phase angle), fluid anti-icing with slinger ring and feed shoes, and electrical de-icing with slip rings, brushes and cycling timers

12%

Propeller Maintenance and Storage

Static and dynamic balancing, blade tracking, damage assessment (nicks, erosion, corrosion, prop strike), repair classification and blending limits, blade-angle rigging, tachometer checks, restricted RPM ranges, installation torque, records, and storage/preservation

How to Pass the EASA Module 17 Exam

What You Need to Know

  • Passing score: 75% per module
  • Exam length: 32 questions
  • Time limit: 40 minutes (B1.1/B1.2/B3); 25 minutes for A1/A2
  • Exam fee: Varies by NAA/Part-147 organisation (approximately EUR 50-230 per module sitting)

Keys to Passing

  • Complete 500+ practice questions
  • Score 80%+ consistently before scheduling
  • Focus on highest-weighted sections
  • Use our AI tutor for tough concepts

EASA Module 17 Study Tips from Top Performers

1Master the governor velocity triangle: in over-speed the flyweights move out, the pilot valve ports oil to coarsen the blades and reduce RPM; in under-speed the blades go finer - know which way oil drives the blades on counterweighted versus non-counterweighted hubs
2Memorise the four blade-load directions: centrifugal force (radially out, the largest), thrust bending (forward), centrifugal twisting moment (toward fine pitch) and aerodynamic twisting moment (toward coarse pitch)
3Learn the feather angle (about 80-90 degrees, edge-on to minimise drag) and that feathering uses springs and counterweights, opposed by anti-feather latches that engage around 800 RPM to prevent ground feathering
4Distinguish synchronising (matching RPM to remove the beat) from synchrophasing (holding a set blade phase angle between propellers) and fluid de-icing (slinger ring) from electrical de-icing (slip rings, brushes and a cycling timer)
5Know the maintenance numbers: blend nicks within the manual's limits with smooth spanwise radii, keep blades within minimum dimensions, check tracking within about 1.5 mm (1/16 inch), and re-balance after any boot or blade work
6Practise the 32-question, 40-minute pace (about 75 seconds per question) and remember the 75% pass mark with no negative marking, so never leave a question blank

Frequently Asked Questions

What is EASA Part-66 Module 17?

Module 17 (Propeller) is one of the basic knowledge modules of the EASA aircraft maintenance licence. It is required for the B1.1, B1.2, B3, A1 and A2 categories and covers propeller theory, construction, pitch control, feathering and reverse, synchronising, ice protection and propeller maintenance.

How many questions are on the Module 17 exam and how long is it?

For categories B1.1, B1.2 and B3 the Module 17 exam is 32 multiple-choice questions to be answered in 40 minutes. For categories A1 and A2 it is 20 questions in 25 minutes. The real exam uses three-option multiple-choice questions.

What is the pass mark for Module 17?

The pass mark for each Part-66 basic module, including Module 17, is 75 percent. There is no negative marking, so candidates should attempt every question. Up to three consecutive attempts are allowed, with a 90-day wait after the third failure.

What changed with Regulation (EU) 2023/989 in June 2024?

Commission Implementing Regulation (EU) 2023/989, applicable from 12 June 2024, merged several split modules, including former sub-modules 17A and 17B, into a single Module 17. Courses that began before the change must complete under the old standard by 12 June 2026.

What topics are most heavily tested in Module 17?

Propeller fundamentals (blade angle, pitch, slip, blade forces and twisting moments) and pitch control with the constant-speed unit and governor carry the most weight, followed by feathering and reverse pitch, construction, ice protection, synchronising and maintenance.

Does this practice test match the real EASA exam format?

Yes in content and difficulty. Note that the real Part-66 exam uses three-option multiple-choice questions, while this free practice bank uses four options to give extra study value; the topics, terminology and standard reflect the current 2023/989 syllabus.