How to get your Part-66 B1.1 licence

The holder of one is what the industry calls a licensed aircraft maintenance engineer. Part-66 is the regulation behind the licence, and B1.1 is the category written on it. That is why the job is advertised in one vocabulary and regulated in another: the regulation talks of certifying staff, and of the applicant for an aircraft maintenance licence.

A Part-66 aircraft maintenance licence lets the holder issue certificates of release to service. Category B1 covers maintenance on aircraft structure, powerplant and mechanical and electrical systems, plus work on avionic systems needing only simple tests and no troubleshooting (66.A.20(a)(2)). It includes the corresponding A subcategory, so B1.1 includes A1.

Under EASA, category B1 has five subcategories, and under the UK CAA four. B1.1 is aeroplanes turbine, B1.2 is aeroplanes piston, B1.3 is helicopters turbine, B1.4 is helicopters piston, and EASA’s fifth, B1.E, is aeroplanes with an electric power plant under 5,700 kg maximum takeoff mass.

Passing the thirteen modules does not, by itself, let you certify a specific aircraft. Aircraft type ratings (66.A.45) and a certifying authorisation from the organisation you work for come afterwards, and are separate from everything on this page, which is one of the five things people most often get wrong.

Thirteen, under both authorities, and they examine the same thirteen subjects. The numbering is not the same. EASA removed the A and B module suffixes on 12 June 2024, so what the UK still calls Modules 7A, 9A, 11A and 17A are simply Modules 7, 9, 11 and 17 under EASA. Modules 12, 13, 14, 16, 18 do not apply to B1.1.

Every basic knowledge exam is multiple choice with 3 answers, one of them correct, and the pass mark is 75%. Penalty marking is not used, and time is fixed at a standard 75 seconds per question, which is why Module 15’s 92 questions get 115 minutes. EASA sets 2 essay questions for B1.1, both in Module 7. The UK CAA sets 4. A pass then lasts 10 years, counted backwards from the date you apply for the licence, not forwards from the day you sat the paper.

5 years of practical maintenance experience on operating aircraft with no previous relevant technical training, 3 years with training as a skilled worker in a technical trade (a route the UK CAA does not offer today, as it recognises no such training), or 2 years after completing an approved Part-147 basic training course (66.A.30(a)(2)). At least one year must be recent experience on turbine aeroplanes, and all of it must fall within the 10 years before you apply. You then apply on Form 19, with documents that prove you meet the knowledge, training and experience requirements. There is no deadline between your final exam and that application. Once issued, the licence runs 5 years from its last issue or change.

It follows from the register of the aircraft you plan to certify, not from where you live. An EASA Part-66 licence is not accepted for certifying aircraft on the UK register, and a UK licence is not recognised in the EU system. Each licence has to come through its own regime. Both authorities examine the same thirteen subjects, but four papers are set differently (Modules 6, 8, 9, 10), and the syllabus itself differs across nine of the thirteen modules, because EASA rewrote Part-66 twice after Brexit and the UK adopted neither change. There is no mutual recognition in either direction, and the UK’s transfer route for EU licence holders closed on 31 December 2022.

Five planning errors cost more time than the material does. Revising the wrong regime’s syllabus is the most common, because nine of the thirteen modules differ and two of them will silently hand you the wrong material. After that: letting the 10 years of validity run out on the modules you passed first, budgeting for 3 years of experience when B1.1 needs 5, assuming the licence alone lets you certify an aircraft, and planning resits without the wait of 90 days.

Study each module from your own authority’s syllabus, and split your time by paper size and knowledge level rather than by how hard a topic feels. Practise in the exam’s format of three answers with one correct, read the explanation behind every answer, and practise recalling answers as well as recognising them. Before you book, sit a full timed paper you have not seen: the pass mark is 75% on every module, and the standard wait after a failed module is 90 days.

Each part of the route above has a page of its own, listed below and linked from its section. The two papers people ask about most are Module 15, Gas Turbine Engine, the paper that makes it a turbine licence, and Module 11, the longest of the thirteen at 140 questions.