The Part-66 B3 Licence for Light Piston Aeroplanes

The Part-66 B3 licence is the light aircraft licence. If you maintain training aeroplanes, tourers and other small piston aeroplanes, B3 lets you certify that work without sitting the longer B1.2 papers or collecting type ratings. This guide explains exactly which aircraft B3 covers, what you may certify, all 13 papers under EASA and UK CAA rules (the category where the two systems differ most), the experience you need, how the licence rating and its limitations work, and how B3 compares with B1.2.

Part-66 Prep is an independent study aid, not EASA, the UK CAA or a Part-147 organisation. For the full list of categories, see the Part-66 licence categories hub.

What the Part-66 B3 licence covers

Part-66 point 66.A.3 defines the category in one sentence: the B3 licence applies to piston-engine non-pressurised aeroplanes of 2,000 kg maximum take-off mass and below. Each part of that definition matters:

• Piston engine. Turboprops and jets are out, even small ones.
• Non-pressurised. A pressurised piston single is outside B3, whatever its weight.
• Aeroplanes. Helicopters, including light piston helicopters, are not covered.
• 2,000 kg MTOM and below. Typical two- and four-seat trainers and tourers fall well inside this; many light twins sit above it.

The same wording appears in the EU text, consolidated in the EASA Easy Access Rules for Continuing Airworthiness, and in the retained UK text on legislation.gov.uk.

Privileges

Under 66.A.20, a B3 licence lets you issue certificates of release to service and act as B3 support staff for maintenance on aeroplane structure, power plant and mechanical and electrical systems, and for work on avionic systems that needs only simple tests to prove serviceability and no troubleshooting. In other words it is B1-style privileges on a narrower set of aircraft. As always, you need a certification authorisation from the organisation you work for, and six months of relevant experience in the previous two years to use the privileges.

B3 modules and papers: EASA vs UK CAA

B3 sits 13 papers. Under UK rules four of them are B3-specific modules: 7B, 9B, 11C and 17B. Under EASA rules Modules 7, 9, 11 and 17 are single modules with a B3 column; on our site the B3 papers for Modules 11 and 17 keep the names 11C and 17B in both systems.

Module	EASA questions / time	UK CAA questions / time
1 Mathematics	32 / 40 min	28 / 35 min
2 Physics	32 / 40 min	28 / 35 min
3 Electrical fundamentals	24 / 30 min	24 / 30 min
4 Electronic fundamentals	20 / 25 min	8 / 10 min
5 Digital techniques	20 / 25 min	16 / 20 min
6 Materials and hardware	80 / 100 min	60 / 75 min
7 Maintenance practices (UK 7B)	80 / 100 min + 2 essays	60 / 75 min + 2 essays
8 Basic aerodynamics	24 / 30 min	20 / 25 min
9 Human factors (UK 9B)	28 / 35 min	16 / 20 min + 1 essay
10 Aviation legislation	44 / 55 min	32 / 40 min + 1 essay
11C Piston aeroplane structures and systems	60 / 75 min	60 / 75 min
16 Piston engine	76 / 95 min	68 / 85 min
17B Propeller	32 / 40 min	28 / 35 min
Total	552 questions + 2 essays	448 questions + 4 essays

Sizes come from Appendix II: the EU version as replaced by Regulation (EU) 2023/989, applicable from 12 June 2024, and the retained UK version. Every paper is three-option multiple choice, 75 seconds per question, 75% to pass.

Key fact: Only two B3 papers have the same number of multiple-choice questions in both systems: Module 3 and Module 11C. Every other B3 paper is longer under EASA rules. Always choose the right rules before you practise.

Why the gap is so large

The UK kept the older Appendix II, which gives B3 its own reduced modules and paper sizes. The EU rewrite in 2023/989 brought B3 up to the same knowledge levels as B1 in several modules: Module 17, for example, now has a single column for B1.1, B1.2 and B3 under EASA rules. Under UK rules, Module 4 asks B3 candidates only for basic semiconductor knowledge (hence 8 questions) and Module 17B is level 2 throughout, including maintenance, where B1 is level 3. The EASA vs UK CAA comparison sets out every difference across all categories.

The UK also adds essays: one in Module 9B and one in Module 10, on top of the two in Module 7B. Under EASA rules only Module 7 has essays.

The modules that make B3 different

Module 11C covers piston aeroplane aerodynamics, structures and systems scoped to B3 aircraft: theory of flight, airframe structures, heating and ventilation, instruments, electrical power, fuel, hydraulics, landing gear, lights and the other systems you find on a light aeroplane, without pressurisation-heavy or large-aircraft content. Practise with Module 11C paper 1.

Module 16 is the piston engine paper and the heaviest technical paper after Modules 6 and 7. It covers theory, construction, carburettors and injection, magnetos, turbocharging, lubrication, indication and ground running. Under UK rules B3 is set lower than B1 in ground operation and storage. Try Module 16 paper 1 for B3, and see the Module 16 guide for each sub-module.

Module 17B is the propeller module scoped to light aircraft: fixed-pitch, ground-adjustable and constant-speed propellers, light twin feathering, ice protection, balancing and damage assessment. Practise with Module 17B paper 1; the Module 17 guide explains the 17A and 17B split.

B3 experience requirements

Basic experience is set by 66.A.30 and is the same as for category A and B1.2:

Route	EASA	UK CAA
No relevant technical training	3 years	3 years
Skilled worker in a technical trade	2 years	2 years in the rule; no recognised course, so not available in practice
Part-147 approved basic course	1 year	1 year

The experience must be practical maintenance on operating aircraft, cover a representative cross section of tasks, include at least one recent year, and fall within the 10 years before you apply. The UK CAA's application page explains the skilled worker point and lists common reasons applications are rejected. The experience requirements guide covers logbooks and evidence.

The B3 rating and its limitations

B3 is the one B category with no type ratings. Under 66.A.45 the only rating is "piston-engine non-pressurised aeroplanes of 2,000 kg MTOM and below", endorsed after you demonstrate practical experience across a representative cross section of maintenance activities.

Unless you show experience on each kind of structure, the rating carries limitations that exclude:

1. wooden-structure aeroplanes
2. aeroplanes with metal-tubing structure covered with fabric
3. metal-structure aeroplanes
4. composite-structure aeroplanes

Most people start with one or two of these lifted, matching the fleet they trained on, and remove the others later by showing appropriate experience or passing a practical assessment by the authority (66.A.50). In the UK, removing limitations from the basic category costs £74 per application as of October 2026, per the CAA's limitations page and Scheme of Charges. The licence application guide explains the process.

B3 also links to the light aircraft category L. The rule says a B3 holder is deemed to meet the basic knowledge and experience requirements for subcategories L1C, L1, L2C and L2 (sailplanes, powered sailplanes and ELA1 aeroplanes).

B3 vs B1.2

	B3	B1.2
Aircraft	Piston, non-pressurised aeroplanes ≤ 2,000 kg	Piston aeroplanes outside Group 1, any weight, pressurised included
Ratings	One B3 rating with structure limitations	Group 3 rating (with limitations) or type ratings
Includes category A privileges	No	Yes, A2
Total questions, EASA	552	660
Total questions, UK CAA	448	612
Experience	3 years, or 1 year after Part-147	3 years, or 1 year after Part-147

The experience is identical, so the choice comes down to the aircraft you work on and how far you want to go. B3 is shorter to study, especially under UK rules. B1.2 opens heavier and pressurised piston aeroplanes and lets you add type ratings. Moving from B3 to B1.2 later is possible: Appendix IV to Part-66 sets 6 months of extra experience for that extension (halved after a relevant Part-147 course), plus the module differences your authority identifies. Going the other way, a B1.2 holder needs no extra experience to add B3. The Part-66 B1 licence guide covers B1.2 in detail.

Sitting the B3 exams

You can take B3 module exams at a Part-147 approved maintenance training organisation or, for UK licences, with the CAA itself. The CAA runs module exams through its e-Exam service on the Customer Portal, at venues that currently include Gatwick, Bristol, Gloucestershire Airport, Rosyth and London Oxford Airport, and charges £60 per attempt as of October 2026. Venues change, so check the CAA's module exam pages before you plan. The CAA booking guide walks through the process.

Under EASA rules you sit at a Part-147 organisation approved by an EU member state authority, or with the authority where it runs exams. EASA papers longer than 90 minutes may be split into two partial exams, which applies to the B3 Module 6, Module 7 and Module 16 papers.

The attempt rules matter on a long licence like this. Under EASA rules you get at most three attempts at a module in any 12-month period; under UK rules three consecutive attempts, then a one-year wait. Both systems require 90 days before a resit, or 30 days after tailored Part-147 retraining. Each pass counts towards a licence application for 10 years. The resit rules guide has worked examples.

Planning the 13 papers

There is no set order, but a sensible sequence for B3 is:

1. Foundation: Modules 1, 2 and 3. Under UK rules these are short B3 papers (28, 28 and 24 questions).
2. Short wins: Modules 4, 5, 8, 9 and 10, together fewer than 100 questions under UK rules.
3. The big two: Module 6 materials and Module 7 maintenance practices, with the Module 7 essays.
4. Aircraft-specific: 11C, 16 and 17B, which make most sense once you have hands-on time on light aircraft.

If you work full time on light aircraft, the aircraft-specific modules can feel easier because they describe your daily work. Mathematics and electrical fundamentals are where career changers may need the most time.

Where B3 engineers work

B3 suits flying clubs and schools, light aircraft maintenance organisations, Part-CAO and Part-145 organisations working on general aviation fleets, and engineers who maintain privately owned aircraft within an approved organisation. There is no official data on pay or job numbers for B3 holders, so check adverts in the area where you want to work. Because B3 does not include category A privileges and stops at 2,000 kg, people who expect to move to larger aircraft often choose B1.2 from the start.

EASA now has 18 modules, after Regulation (EU) 2025/111 added Module 18 and the B1.E subcategory for electric aeroplanes from 13 February 2026. B3 itself is unchanged by that.

Your study plan

1. Decide whether you are sitting EASA or UK CAA exams, since the papers differ by more than 100 questions in total.
2. Take the free B3 diagnostic: 20 questions across the B3 modules.
3. Start with Modules 1, 2 and 3, then the short Modules 4, 5, 8, 9 and 10. Every module has a free paper 1 and quick practice in the B3 practice hub.
4. Move on to Modules 6 and 7, practising essays for 7 (and for 9 and 10 under UK rules).
5. Finish with 11C, 16 and 17B, which build on your practical work.
6. Unlock papers 2 to 10, sub-module drills and all study notes with Pro when you need them, and book each module once you score 85% or more on three different papers.