How to Become a B1 Licensed Aircraft Engineer

Wondering how to become a B1 engineer? A B1 licensed aircraft engineer certifies maintenance on aircraft structures, engines and mechanical and electrical systems, and is the person who signs an aircraft back into service after work on the line. Getting there takes exams, experience and paperwork in a set order. This guide walks through every step, how long each route takes, what it costs and how to study alongside a full-time job.

Part-66 Prep is an independent study aid, not an authority, employer or training organisation. The rules are Part-66 in Regulation (EU) No 1321/2014 for EASA licences and the retained UK Part-66 for UK licences. For the B1 privileges and module list in detail, read the Part-66 B1 licence guide; for every aviation maintenance career route, see how to become an aircraft engineer.

What a B1 aircraft engineer is

B1 is the mechanical category of the Part-66 aircraft maintenance licence. A B1 engineer may issue a certificate of release to service for maintenance on structure, powerplant and mechanical and electrical systems, and for avionic work that needs only simple tests. B1 includes the matching category A subcategory, so a B1.1 can also do the minor line tasks of an A1. B1 engineers also act as support staff in base maintenance.

There are four subcategories. This site covers the three with Part-66 Prep papers:

Subcategory	Aircraft	Modules
B1.1	Turbine aeroplanes	1 to 10, 11A, 15, 17A (13 modules)
B1.2	Piston aeroplanes	1 to 10, 11B, 16, 17A (13 modules)
B1.3	Turbine helicopters	1 to 10, 12, 15 (12 modules)
B1.4	Piston helicopters	1 to 10, 12, 16

B1.1 is by far the most common choice because airlines and large maintenance organisations work on turbine aeroplanes. Choose the subcategory that matches the aircraft you work on or want to work on.

How to become a B1 engineer: the steps

1. Decide on EASA or UK. Work out where you will work. UK-registered aircraft need a UK licence; EU operators need an EASA licence from a member state authority. Since 2021 the two are separate, and the EASA vs UK CAA guide explains the differences.
2. Choose your route. A Part-147 basic course (often as an apprenticeship) or self-study while working. The route sets your minimum experience.
3. Pass the modules. Thirteen exams for B1.1 or B1.2, twelve for B1.3, in any order. Each pass is recorded on a certificate of recognition and counts for 10 years.
4. Build and record experience. Practical maintenance on operating aircraft, recorded in a logbook and countersigned by supervisors.
5. Apply for the licence. Send your module certificates, experience evidence and the application form and fee to your competent authority.
6. Get type rated. For group 1 aircraft, complete an approved type course and, for your first type in the subcategory, on-the-job training.
7. Get a certification authorisation. Your employer assesses you and issues an authorisation that lets you use your licence privileges in their organisation.

The rest of this guide takes each step in turn.

Step 1 and 2: choosing your route

The route you take decides how much experience you need under 66.A.30.

Route	B1.1 and B1.3	B1.2 and B1.4
Part-147 approved B1 basic course	2 years experience	1 year
Skilled worker in a relevant technical trade	3 years	2 years
No relevant technical training	5 years	3 years

At least one year must be recent experience on the subcategory you apply for, and the experience must fall within the 10 years before your application. In the UK, the CAA currently recognises no course for the skilled worker reduction, so UK candidates in practice use the Part-147 or no-training figures. The experience requirements guide covers what counts.

The Part-147 or apprenticeship route

Airlines and maintenance organisations recruit apprentices who complete a Part-147 approved basic course, sit the module exams at the school, and gain experience in the hangar. Full-time Part-147 courses are also available to self-funding students. This is the fastest route to the licence, and the exams are built into the course. The catch is competition for apprenticeship places and the cost of self-funding.

The self-study route

Many B1 engineers start as mechanics or come from the military or another engineering trade, and sit their modules one at a time. You earn while you study, and you can pace the modules around shifts. The longer experience requirement often overlaps with the years you would spend studying anyway. The Part-66 self-study guide explains how to plan it.

Key fact: Experience and exams run in parallel. Nothing stops you sitting modules in your first year as a mechanic, and every month of logged experience counts towards the licence while you study.

Step 3: passing the modules

The B1.1 modules and their paper sizes under EASA rules (UK sizes in brackets where different):

Module	Questions
1 Mathematics	32
2 Physics	52
3 Electrical fundamentals	52
4 Electronic fundamentals	20
5 Digital techniques	40
6 Materials and hardware	80 (UK 72)
7 Maintenance practices	80 plus 2 essays
8 Basic aerodynamics	24 (UK 20)
9 Human factors	28 (UK 20 plus 1 essay)
10 Aviation legislation	44 (UK 40 plus 1 essay)
11A Turbine aeroplane structures and systems	140
15 Gas turbine engine	92
17A Propeller	32

That is 716 multiple-choice questions under EASA rules and 692 under UK rules. Every paper has three options, a 75% pass mark and about 75 seconds a question. The two largest are Module 11A at 140 questions and Module 15 at 92. Module 7 is the one with essays in both systems.

A sensible order

No order is required, but this sequence suits most people:

1. Modules 1, 2 and 3, the maths, physics and electrics everything else uses.
2. Modules 8, 9 and 10, which are short and fairly self-contained, for early passes.
3. Modules 4, 5 and 6.
4. Module 7, with essay practice.
5. The aircraft and engine modules: 11A, 15 and 17A for B1.1.

If you fail a module

You wait 90 days before a retake, or 30 days after a Part-147 retraining course tailored to the failed subjects. Under EASA rules you get at most three attempts at a module in any 12 months; under UK rules three consecutive attempts, then a one-year wait. Book when you are consistently scoring well above 75%, not when you are hovering around it.

Studying alongside a full-time job

Most self-study B1 candidates work shifts. What tends to work:

• One module at a time, with a booked exam date six to twelve weeks out. A date makes the study real.
• Short daily sessions rather than occasional long ones. Twenty questions on a break, a note on the bus.
• Use your work. When you meet a system in the hangar, read the matching sub-module that week.
• Timed papers before booking. Sit full papers at the real size so the exam holds no surprises.
• Keep certificates safe. Every module pass is needed for the application, and passes count for 10 years.

The free B1.1 diagnostic gives you a 20-question snapshot across all B1.1 modules, and the B1.1 practice hub has a free timed paper 1 for each module.

Step 4: recording experience

Your experience must be practical, on operating aircraft, and cover a representative cross-section of maintenance tasks for the subcategory. Record it as you go in a logbook, with tasks, aircraft, dates and supervisor signatures. In the UK, the CAA publishes a logbook format in CAP 741. Gaps in a logbook are much harder to fill later than to avoid now.

Step 5: applying for the licence

When you hold all module passes for the subcategory and enough experience, you apply to your competent authority: the UK CAA for a UK licence, or the authority of an EU member state for an EASA licence. You send the application form, certificates of recognition, experience evidence and the fee. In the UK, the CAA charges £455 for an AML application (CAA Scheme of Charges, as of October 2026). The licence application guide explains what to send and common reasons applications are returned.

Your first licence may carry limitations, for example if your experience did not cover some systems. These can be removed later with further experience or exams.

Step 6: type ratings

A licence alone does not let you certify every aircraft. For group 1 aircraft (complex motor-powered aircraft, multi-engine helicopters, aeroplanes certified above FL290 and fly-by-wire aircraft) you need an individual type rating for each type. That means an approved type training course with theory and practical elements, and for your first type in the subcategory, a period of on-the-job training on that type. Employers normally arrange and pay for type courses for their own engineers.

For simpler aircraft in groups 2 and 3, the licence can carry group or subgroup ratings instead. The Part-66 type ratings guide explains the groups and how ratings are added. In the UK, adding a type rating costs £183 (as of October 2026).

Step 7: the certification authorisation

The last step is the one people forget. Even with a licence and a type rating, you can only sign a certificate of release to service when your employer, an approved maintenance organisation, issues you a certification authorisation. The organisation checks your licence, training and competence, and the authorisation lists exactly what you may release. You also need six months of relevant experience in the preceding two years to use your privileges. Change employer and you need a new authorisation; the licence goes with you.

Where B1 engineers work

Once licensed, B1 engineers have a wide choice of workplaces:

• Airline line maintenance, turning aircraft round at airports, often on shifts, rectifying defects reported by crews and signing the release before departure.
• Base maintenance, in hangars during scheduled checks, working as B1 support staff alongside B2 colleagues and the category C certifier who releases the aircraft after the check.
• Helicopter operators, for offshore, emergency medical, police and charter flying, where B1.3 engineers often work at remote bases.
• Business and general aviation, where small teams mean broad work and, frequently, engineers who hold more than one category.
• Contract work, where licensed engineers with in-demand type ratings move between organisations on fixed-term contracts.

Pay depends heavily on country, employer, shift pattern and type ratings. No official salary figures are published, so look at current job adverts for the region and aircraft you are interested in. What is consistent is that licence and type ratings, not years alone, drive progression: a mechanic becomes a certifying engineer when the licence and authorisation arrive.

Exam tip: If you already work as a mechanic, ask your organisation's training department early. Many will sponsor module exams or type courses once you show steady progress, and some tie sponsorship to a period of service afterwards.

What it costs to become a B1 engineer

Costs vary enormously by route and country, and much of it is often covered by employers.

Cost	UK figure (as of October 2026)	Notes
CAA module exam	£60 per attempt	Part-147 organisations set their own exam prices
AML application	£455	per CAA Scheme of Charges
Adding a type rating	£183	the type course itself is a separate, larger cost
Licence renewal every 5 years	£455	administrative renewal, no exams
Part-147 basic course	varies widely	often funded through apprenticeships
Type training course	varies widely	usually paid by the employer

As an illustration only, a self-study B1.1 candidate who passes all 13 modules first time at CAA venues pays 13 times £60, which is £780, plus £455 for the licence: £1,235 in fees. Resits, travel, books and courses come on top. EASA authorities and Part-147 organisations set their own fees, so check locally. The Part-66 licence cost guide breaks it down further.

Your study plan

1. Take the free B1.1 diagnostic to see where you stand.
2. Choose your route and subcategory, and start a logbook now if you work in maintenance.
3. Book your first module (most people start with Module 1, 2 or 3) six to ten weeks out, and use its free paper 1 and quick practice.
4. Work through the modules in order, booking each when you score 85% or more on three different papers. Pro gives papers 2 to 10 for every module and all study notes.
5. When the modules and experience are complete, follow the application guide, then ask your employer about type training.