Propeller EASA Part-66 — Module 17 Practice Questions

What Module 17 covers — in plain English

Module 17 of the EASA Part-66 syllabus covers everything the licensed engineer needs to know about propellers — from the blade-element aerodynamics that produce thrust through to the constant-speed units, governors, ice-protection systems and balancing procedures that keep them serviceable. It is one of the more practical modules: most of the failure modes you study here have a direct, visible counterpart on the flight line, which is why section 17.6 (Maintenance) is examined at knowledge level 3 for B1.1, B1.2 and B3 candidates while everything else sits at level 2. Static and dynamic balancing, blade tracking, blending damage and cropping limits all appear regularly in the question bank, and unlike the more theoretical modules the wrong answers tend to look very plausible to anyone who hasn't spent time on a hangar floor.

The bulk of the exam pressure comes from pitch control — speeder springs, flyweights, on-speed/under-speed/overspeed conditions, feathering circuits, reverse pitch and the beta range. Many questions hinge on small details: which way CTM and ATM try to move the blade, what holds the prop on the fine-pitch stop, how the CSU governor reacts to a change in TAS, and which oil supply feeds the pitch servo in single-acting versus double-acting designs. The synchronising and synchrophasing sections add a second layer — distinguishing matched RPM from matched phase angle, and remembering that synchrophasing uses pulse probes feeding a single phase-angle controller while basic synchronising only trims a slave engine's governor to match the master. Ice-protection questions are simpler but catch candidates out on the alcohol type (isopropyl, not ethyl or glycol) and on fast/slow cycle timing.

Module 17 only applies to candidates whose licence scope includes propeller-driven aircraft: A1 and A2 (piston aeroplanes), B1.1 (turbine aeroplanes), B1.2 (piston aeroplanes) and B3 (piston aeroplanes ≤ 2000 kg). B2 avionics and B1.3/B1.4 helicopter candidates do not sit this paper under the 2023/989 amendment (B1.3 was removed entirely, and the small B2 carve-out for 17.1/17.2 at level 1 was dropped). Candidates renewing from a pre-2024 licence should pay particular attention to the new category split — A2 and B1.2 now sit at level 2 across all sections (previously level 1), so the question style aimed at those candidates has shifted from pure recognition towards applied understanding of the systems. The full per-section knowledge-level breakdown, including the level-3 Maintenance carve-out and the storage/preservation section that's often skipped in revision, is on our Module 17 syllabus page.

These samples are drawn from our live Module 17 question bank of 802 questions. The full timed practice quiz draws 32 questions per attempt (or 20 for Cat A), scored against the official EASA 75 % pass mark, with weak-area tracking across attempts.