Part-66 Essay Questions: How They Are Marked and How to Pass

Part-66 essay questions are the one part of the basic knowledge examination where you write rather than pick an answer. They are short, 20 minutes each, but they cause a disproportionate number of fails because candidates prepare for them less than for multiple choice. This guide explains which modules have essays under EASA and UK CAA rules, how key-point marking works, a reliable 20-minute method, the subject areas that come up, and how to practise.

Part-66 Prep is an independent study aid. The essay rules are in Appendix II to Part-66: for EASA licences in Regulation (EU) No 1321/2014 with Appendix II replaced by Regulation (EU) 2023/989 from 12 June 2024, and for UK licences in the retained UK Part-66. The CAA's engineer knowledge requirements page confirms the UK position. For all exam rules in one place, see Part-66 exams.

Which modules have Part-66 essay questions

Module	EASA (from 12 June 2024)	UK CAA
7 Maintenance practices	2 essays	2 essays (7A; 7B for B3)
9 Human factors	None	1 essay (9A; 9B for B3)
10 Aviation legislation	None	1 essay
Total per licence	2	4

Every category that sits these modules writes the essays, including B2 and B2L, whose Module 7 multiple-choice paper is shorter. Each essay is allowed 20 minutes on top of the multiple-choice time.

The difference comes from the 2024 change to the EU exam standard, which the UK did not adopt. The UK's January 2026 consultation (RMT 0201) proposes adopting the revised syllabus, with the law expected in 2027 and most of it in force in 2029, but the draft does not make clear whether the UK Module 9 and 10 essays will survive. For now, UK candidates write four essays and EASA candidates two. The EASA vs UK CAA guide sets out the other differences.

Key fact: Under UK rules you meet essays early. Modules 9 and 10 are usually among the first modules people sit, so UK candidates need essay technique months before Module 7. EASA candidates meet essays only in Module 7, often one of their later modules.

How Part-66 essays are marked

The marking rules are the same in both systems.

1. Each essay has a model answer, prepared by the examiner and broken down into key points: the facts, steps and precautions a competent answer must contain.
2. You pass with 75% of the required key points, provided there is no significant error on a required key point. A significant error is one that would be unsafe or plainly wrong, for example a reversed procedure or a missing safety step.
3. Essays are marked separately from the multiple choice. If you pass one part and fail the other, you retake only the failed part.
4. New essay questions are raised regularly. Under 66.B.200, authorities must raise new essay questions at least every six months, and questions are kept secure. There is no point trying to memorise "the" essays.

What this means in practice: the examiner is ticking off points. Every relevant point you make clearly and correctly is a tick. Padding, repetition and elegant prose earn nothing, and a confident wrong statement on a key safety step can sink an otherwise good answer.

Exam tip: An essay that covers ten points briefly will usually beat one that covers five points beautifully. Breadth of correct, relevant points is what the marking rewards.

How long should a Part-66 essay be?

No word count is set anywhere in the rules. Training organisations generally advise writing in full sentences and paragraphs rather than bullet notes, because the examiner needs to see that you understand the sequence and reasoning, not just the keywords. In 20 minutes, a typical answer is somewhere around a page to a page and a half of handwriting. Aim for complete, then for clear, and only then think about length.

A 20-minute method that works

Twenty minutes is not long. A fixed routine stops you running out of time or leaving out whole areas.

Minutes 0 to 3: plan

Read the question twice and underline the task word: describe, explain, list the precautions for, state the requirements of. Then write a quick list of every point you can think of in the margin or on rough paper. Do not filter yet.

Sort the list into an order. For practical Module 7 tasks, a simple frame covers most questions:

• Before: documentation and approved data, tooling and calibration, safety precautions, preparation of the aircraft and area
• During: the procedure step by step, values and limits, inspections at each stage
• After: functional or leak checks, duplicate inspections where required, restoring the aircraft, recording the work and certifying

Minutes 3 to 18: write

Write in short paragraphs that follow your plan. Use correct technical terms, and name documents properly: the aircraft maintenance manual, the approved data, the task card, the certificate of release to service. State values or limits as "as specified in the maintenance manual" unless the question gives figures; never invent a number.

Minutes 18 to 20: check

Read back against your plan. Tick off each point. If one is missing, add a sentence at the end; examiners mark content, not neatness. Check for any statement that might be read as unsafe.

Exam tip: Almost every Module 7 model answer includes safety, use of approved data and recording the work. Those three are easy key points that candidates forget because they seem obvious.

A worked plan: turning a question into key points

Here is how the three-minute plan looks for a practice question we wrote ourselves: "Describe how you would fit lockwire to a pair of bolts on an engine component."

A quick brainstorm, sorted into the frame:

• Before: identify the task in the approved maintenance data; check the correct lockwire material and diameter; gather the right tools (pliers, twisting tool) and confirm the bolts are torqued to the specified value first; check for damaged or previously used holes.
• During: insert the wire through the first bolt; route it so that any tendency of the bolt to loosen tightens the wire (the positive direction); twist to the specified number of twists per unit length without nicking the wire; pass it through the second bolt and finish with a pigtail of the specified length bent back to avoid snagging; never reuse lockwire.
• After: inspect for correct direction, tension and no damage; carry out an independent inspection if the task is on a critical system; remove all off-cuts and account for tools; record the work and certify it.

That is about a dozen distinct points. A model answer would contain most of them, and the most important (torque first, positive direction, no reuse, inspection and recording) are exactly the kind of points whose absence counts as a significant error. Written up in full sentences, in that order, it comfortably fills 15 minutes.

Notice what is not in the plan: no invented torque figures, no twist counts from memory, no history of lockwire. Where a value matters, the answer refers to the maintenance manual. That is what a certifying engineer does on the job, and it is what the examiner wants to see.

Typical essay subject areas

We do not publish or reconstruct real exam essay questions, and nobody outside the exam system has them. What we can describe are the subject areas the syllabus points to, based on the UK CAA guidance and the Appendix I content.

Module 7 maintenance practices

Practical tasks and the precautions around them, for example:

• applying torque to fasteners and fitting locking devices (split pins, lockwire, self-locking nuts)
• crimping, splicing and inspecting electrical wiring, connectors and bonding
• entering a fuel tank safely, including preparation and atmosphere checks
• inspections after abnormal events, such as a lightning strike, heavy landing or flight through severe turbulence
• handling, storing and identifying parts and materials, and controlling tools
• disassembly, inspection and repair practices, and engineering drawings

Our Module 7 questions page explains every Module 7 sub-module.

Module 9 human factors (UK only)

Essays tend to ask you to explain a human factor and how it is managed in maintenance: fatigue and shift patterns, communication at shift handover, the effect of stress and time pressure, error types and how errors are caught, or a set of common causes such as the "Dirty Dozen". Good answers link the theory to a concrete maintenance situation and to the organisation's controls. The CAA's 2002 introduction to human factors for engineers, CAP 715, is marked as reference only, but it is still useful background. See the Module 9 questions page.

Module 10 aviation legislation (UK only)

Essays ask you to explain a regulatory concept in your own words: the certificate of release to service and who may issue it, privileges and conditions of certifying staff, occurrence reporting, the role of approved maintenance organisations, continuing airworthiness responsibilities, or the licence and its validity. Precise regulatory terms matter here, and answers must reflect UK law for a UK exam. The Module 10 questions page covers the content.

Common reasons essays fail

1. Answering a different question. Writing everything you know about fuel systems when the question asked about tank entry safety.
2. Missing the before and after. Describing the task well but skipping preparation, inspection and documentation.
3. Bullet-point notes. Lists of keywords without the sequence and reasons behind them.
4. Invented figures. Quoting torque values or limits from memory instead of referring to the manual.
5. Running out of time on the first essay and rushing the second. Watch the clock at 20 and 40 minutes.
6. Unreadable handwriting. If the examiner cannot read a point, it cannot be ticked.

Credits and resits for essays

If you fail only the essay part, you retake only the essay, with the same resit rules as any module: a 90-day wait, or 30 days after a tailored Part-147 retraining course. Under EASA rules the three-attempts-in-12-months limit applies; under UK rules three consecutive attempts, then a one-year wait.

Under UK rules, the CAA states that an essay pass at category A level counts as equivalent to a category B pass. So an engineer who passed the Module 10 essay for category A does not have to write it again when moving to B1 or B2. Our free UK CAA module exams guide summarises this with the other UK rules.

How to practise Part-66 essays

Writing is a skill, and it improves only with practice:

1. Collect the Module 7 (and for UK, 9 and 10) sub-module headings and turn each into a "describe" or "explain" question of your own.
2. Write one essay by hand, timed at 20 minutes, two or three times a week in the run-up to the exam.
3. Mark it yourself against a list of key points from your notes and the syllabus, or ask an experienced engineer or instructor to mark it.
4. Rewrite the weakest essay the next day without looking at the first version.

Our Module 7 essay writing note sets out the method with worked structures (a preview is free; the full note is part of Pro). The Part-66 Prep app has an essay coach with original Module 7 prompts, plus UK Module 9 and 10 prompts, and a self-check rubric based on key points. The website does not mark essays, but every Module 7 paper's start screen tells you how many essays the real exam has, so you can add them to a timed session.

Your study plan

1. Check which system you are sitting under, and so how many essays you face: two (EASA) or four (UK).
2. Read the essay writing note and learn the before, during and after frame.
3. Sit the free Module 7 paper 1 and write two timed essays straight after it to simulate the full exam.
4. UK candidates: add a Module 10 essay after the free Module 10 paper 1, and a Module 9 essay after your Module 9 practice.
5. Keep writing at least two timed essays a week until the exam, and book only when you can cover most key points comfortably in 20 minutes. Pro adds papers 2 to 10 for both modules and all study notes.