B1 vs B2 licence: which should you choose?
B1 is the mechanical licence: structure, engines and mechanical systems. B2 is the avionics licence: electrical and avionic systems, including fault-finding. Both take the same experience and a similar number of exams, so choose by the work you want to do.
- Same experience: five years, or two after an approved Part-147 course1
- Similar exams: in the UK, 692 questions for B1.1 and 652 for B2, plus four essays each3
- More UK adverts ask for B1, but no source shows that either pays more1314
- You can add the other later, with one year of experience and the missing modules16
Updated 24 October 2026 · sources checked 23 October 2026 · Sources
What each licence lets you sign for
Both are “certifying” licences: the holder signs the certificate of release to service that returns an aircraft to flight after maintenance. They split the aircraft between them.
B1Mechanical
Point 66.A.20 of UK Part-661:
- Aircraft structure, powerplant, and mechanical and electrical systems
- Avionic work that needs only a simple test to prove it serviceable, with no troubleshooting
- Includes the matching Category A subcategory
- Not avionic fault-finding
B2Avionics
Point 66.A.20 of UK Part-661:
- Avionic and electrical systems, troubleshooting included
- Electrical and avionic tasks inside engines and mechanical systems that need only a simple test
- Minor scheduled line maintenance and simple defect rectification, on tasks endorsed on your authorisation that you did yourself
- No Category A subcategory; mechanical work only through that endorsed-task privilege
The CAA’s guidance defines a simple test as one in the approved maintenance data whose result is a single go / no-go indication, using aircraft controls, built-in test equipment, the central maintenance computer or test equipment that needs no special training, and taking no more than 10 actions. Troubleshooting, finding the root cause of a defect, is outside it4. In practice a B1 can change a box and release it on a passed built-in test; when the test fails and the fault has to be found, that is B2 work.
Electrical systems belong to both licences: power generation and distribution, lighting, and wiring work such as continuity and bonding checks, crimping and connector pins4. Instruments are formally B2, but a B1 may release electromechanical and pitot-static components4.
Once you hold either licence you still cannot sign for a large aircraft until it carries that aircraft’s type rating1 and your employer issues you a certification authorisation19. On Group 2 aircraft, the simpler types outside Group 1, the two licences diverge again: a B1 earns a subgroup rating by holding two or three type ratings, a B2 by showing a representative range of experience1.
Modules and exams: ten shared, then different
The UK papers for B1.1 (turbine aeroplanes, the most common B1) and B2, from Appendix II of UK Part-663. Questions and time per paper; bold marks the licence examined harder in a shared module.
| Module | B1.1 | B2 |
|---|---|---|
| 1. Mathematics | 32 · 40 min | 32 · 40 min |
| 2. Physics | 52 · 65 min | 52 · 65 min |
| 3. Electrical Fundamentals | 52 · 65 min | 52 · 65 min |
| 4. Electronic Fundamentals | 20 · 25 min | 40 · 50 min |
| 5. Digital Techniques / Electronic Instrument Systems | 40 · 50 min | 72 · 90 min |
| 6. Materials and Hardware | 72 · 90 min | 60 · 75 min |
| 7A. Maintenance Practices | 80 + 2 essays · 100 + 40 min | 60 + 2 essays · 75 + 40 min |
| 8. Basic Aerodynamics | 20 · 25 min | 20 · 25 min |
| 9A. Human Factors | 20 + 1 essay · 25 + 20 min | 20 + 1 essay · 25 + 20 min |
| 10. Aviation Legislation | 40 + 1 essay · 50 + 20 min | 40 + 1 essay · 50 + 20 min |
| 11A. Turbine Aeroplane Aerodynamics, Structures and Systems | 140 · 175 min | — |
| 13. Aircraft Aerodynamics, Structures and Systems | — | 180 · 225 min |
| 14. Propulsion | — | 24 · 30 min |
| 15. Gas Turbine Engine | 92 · 115 min | — |
| 17A. Propeller | 32 · 40 min | — |
| Total | 13 exams · 692 questions + 4 essays | 12 exams · 652 questions + 4 essays |
Every multiple-choice question has three options, 75 seconds are allowed per question, and the pass mark is 75% in every module and every essay3. The B2 Module 13 paper may be split into two sittings3.
Inside the shared modules the levels differ too. B2 is examined at a higher level in electronics, Modules 4 and 5; B1 in materials, hardware and hand skills, Modules 6 and 7A, and in the UK syllabus also in four rows of Module 2 physics (statics, kinetics, mass and viscosity)2. If maths and electronics theory suit you, B2 plays to that; if you would rather rivet, rig, inspect structure and work on engines, B1 does.
The other B1 subcategories swap the aeroplane and engine modules: B1.2 (piston aeroplanes) takes 11B, 16 and 17A; B1.3 (turbine helicopters) takes 12 and 15; B1.4 (piston helicopters) takes 12 and 162. B2L is a narrower avionics licence for aircraft outside Group 1, built from system ratings (com/nav, instruments, autoflight, surveillance, airframe systems)1, and B3 covers piston aeroplanes of 2,000 kg and below1.
Experience: the same for both
Point 66.A.30 of UK Part-66 sets one requirement for B1.1, B1.3 and B21.
| Your training | B1.1, B1.3, B2 | A, B1.2, B1.4, B3 |
|---|---|---|
| None relevant | 5 years | 3 years |
| “Skilled worker” training (not available in the UK, see below) | 3 years | 2 years |
| An approved Part-147 basic training course | 2 years | 1 year |
The experience is practical maintenance on operating aircraft, at least a year of it recent and on the category you apply for, all within the ten years before you apply1. The middle row exists in law, but the CAA says no course is currently recognised for it, so the reduction is not available5. The approved basic courses are the same length for both licences: at least 2,400 hours for B1.1 and for B28.
What changes is what your logbook must show. The CAA expects a B licence applicant’s record to go beyond simple functional and operational checks: troubleshooting and fault diagnosis in the chapters of your licence, and for B2 the use of avionic test equipment5. An initial B2 applicant must also show the mechanical line tasks the B2 privilege covers: ground handling, servicing, general inspections and component changes6.
Jobs and pay in the UK
What the adverts showed on 23 October 2026.
There are more B1 adverts. Of the UK adverts on aviationjobsearch.com that day, 28 job titles named B1 only, 17 named B2 only and 4 asked for either or both1314. Typical B1 titles named line stations and narrow-body types (Heathrow, Edinburgh, Belfast, Luton; A320, 737); typical B2 titles named helicopter operators and maintenance organisations. The workforce has long been B1-heavy: the last count by category we found, from 2004, had 2,038 B1.1 holders and 936 B2 holders16.
No source shows that either pays more. One advertised band, £72,061 to £82,881, appeared on both a B1 and a B2 advert that day1314. Some pages quote a much lower B2 salary; we found no source for those figures. What moves pay is type ratings, shift pattern and holding both licences: one recruiter guide puts type-rated engineers who hold both at £69,000 to £80,000 and more15. The salary guide has the sourced figures.
How to choose
Neither licence is the easy one, and neither closes the other off. Four questions decide it.
- 1
What do you want to work on?
Structure, engines, landing gear, flight controls and hydraulics are B1. Radios, displays, autopilots, wiring and computers, and finding the fault in them, are B2.
- 2
Which theory suits you?
B2 carries more electronics: 40 questions in Module 4, 72 in Module 5 and 180 in Module 13. B1 carries more materials, hardware and practices, and the aeroplane, engine and propeller modules3.
- 3
- 4
B1.1 → B2Adding avionics
| Rule | UK CAA Part-66 | EASA Part-66 |
|---|---|---|
| Essays | Modules 7A, 9A and 103 | Module 7 only9 |
| B2 Module 13 paper | 180 questions, 225 minutes3 | 188 questions, 235 minutes9 |
| Module 2 physics for B2 | Lower than B1 in four rows2 | One level for B1 and B29 |
| Failed module | Three consecutive attempts, then a one-year wait3 | Three attempts in any 12 months9 |
| Electric aeroplanes | No B1.E; a CAA exemption until 31 January 202811 | B1.E and Module 18 since 13 February 202610 |
| Licence recognition | Separate since 1 January 2023: an EASA licence is not valid on UK-registered aircraft12 | |
The CAA has proposed its own update, including a B1.E and a restructured syllabus, with most of it in force from 2029. It is a proposal, not law17.
Practise the modules for your licence
Part66Online has practice questions with an explanation for every answer, and timed mock exams, for every module. Our question bank follows the current EASA syllabus; for UK Module 10 we have a separate set written to UK law.
Sitting UK CAA exams? Use the UK CAA Module 10 questions for the law paper, and check the topics and paper length of the other modules against the CAA before your exam.
B1 and B2: common questions
Is B2 easier than B1?
Not by the rules. Both need the same experience (five years, or two after an approved Part-147 course)1, the approved courses are the same length (2,400 hours)8, and in the UK a B1.1 sits 692 exam questions against 652 for a B23. They are hard in different places: B2 goes deeper into electronics and has the longest paper of all, Module 13 at 180 questions; B1 goes deeper into materials, hardware and hand skills.
Can a B1 engineer sign for avionics work?
Yes, within a limit. A B1 may release avionic work that needs only a simple test to prove it serviceable and no troubleshooting1. A simple test gives a go / no-go answer, uses aircraft controls, built-in test equipment or test equipment needing no special training, and takes no more than 10 actions4. Finding the fault needs a B2.
Can a B2 engineer sign for mechanical work?
Only the electrical and avionic tasks inside engines and mechanical systems that need a simple test, plus minor scheduled line maintenance and simple defect rectification on tasks endorsed on your authorisation that you did yourself1. A B2 licence includes no Category A, while a B1 includes the matching A subcategory1.
Which pays more, B1 or B2?
We found no sourced evidence that either pays more in the UK. On 23 October 2026 the same advertised band, £72,061 to £82,881, appeared on a B1 advert and on a B2 advert1314. Type ratings and shift pattern move pay more than the letter does; one recruiter guide puts engineers who hold both B1 and B2, type-rated, at £69,000 to £80,000 and more15. Our salary guide has the figures.
Can I hold both B1 and B2?
Yes, on one licence. Once you hold one category you add the other with one more year of relevant experience (six months if you completed a relevant approved Part-147 course) and exams in the modules you are missing16. For a UK B1.1 adding B2 the CAA lists parts of Modules 4, 5 and 13 and sub-module 7.4; Module 14 is not required6.
Do I need B1 or B2 to get Category C?
In the UK, yes: the CAA requires an existing type-rated UK Part-66 licence in B1 or B2, and three years exercising B1.1, B1.3 or B2 privileges on complex aircraft or as support staff71. The academic route to C written into the regulation is not available in the UK, because the CAA recognises no degree for it7.
Does an EASA B1 or B2 count in the UK?
No. Since 1 January 2023 the UK has not recognised EASA licences for maintaining UK-registered aircraft, and it accepts no EASA Part-147 certificate dated after 31 December 202212. The two systems now have separate licences and separate syllabus texts.
Is there a B1.E licence for electric aircraft in the UK?
Not yet. EASA added B1.E (electric aeroplanes under 5,700 kg) and Module 18 from 13 February 202610. In the UK, B1.1, B1.2 and L2C holders can certify such aircraft on conditions set by a temporary CAA exemption, valid until 31 January 202811, and the CAA has proposed a UK B1.E; that proposal is not law17.
Sources
Every figure and rule on this page, with where it comes from. Checked 23 October 2026.
- 1UK Regulation (EU) No 1321/2014, Annex III (Part-66), as in force in the UKlegislation.gov.uk
- 2UK Part-66 Appendix I: basic knowledge requirementslegislation.gov.uk
- 3UK Part-66 Appendix II: basic examination standardlegislation.gov.uk
- 4Acceptable Means of Compliance and Guidance Material to UK Regulation 1321/2014 (GM 66.A.20(a))UK Civil Aviation Authority · March 2026 edition
- 5Engineer experience requirementsUK Civil Aviation Authority
- 6Add a category or sub-category to a UK Part-66 aircraft maintenance licenceUK Civil Aviation Authority
- 7Add category C privileges to a UK Part-66 aircraft maintenance licenceUK Civil Aviation Authority
- 8UK Regulation (EU) No 1321/2014, Annex IV (Part-147), Appendix I: basic training course durationlegislation.gov.uk
- 9Easy Access Rules for Continuing Airworthiness (Part-66 as amended by Regulation (EU) 2023/989)EASA · September 2025
- 10Commission Implementing Regulation (EU) 2025/111 (B1.E and Module 18, applies from 13 February 2026)EUR-Lex
- 11General Exemption E6529: certifying electric aeroplanes (valid until 31 January 2028)UK Civil Aviation Authority
- 12Engineer licensing requirements after 1 January 2023UK Civil Aviation Authority
- 13Job search "B1", UK advertsaviationjobsearch.com · read 23 October 2026
- 14Job search "B2", UK advertsaviationjobsearch.com · read 23 October 2026
- 15Licensed Aircraft Engineer Salary GuideMane Contract Services · correct as of October 2026
- 16Engineer Licensing Statistics: age profile of Part-66 licence holders, 1 June 2004UK Civil Aviation Authority · 26 October 2004
- 17Consultation: update to UK Regulation (EU) No 1321/2014 (RMT.0201), closed 13 April 2026UK Civil Aviation Authority
- 18British Airways, Aircraft Maintenance (Spring) apprenticeship, start 1 March 2027Find an apprenticeship (GOV.UK) · posted 19 October 2026
- 19UK Regulation (EU) No 1321/2014, Annex II (Part-145), point 145.A.35: certifying stafflegislation.gov.uk
More career guides
Whichever licence you choose, the modules come first
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