B1.E aircraft type ratings and OJT: what happens after the licence category?

The B1.E licence category is only the starting point

Under the UK CAA and EASA Part-66 systems, holding a basic B1.E licence category does not automatically authorise an engineer to release every aircraft within that category to service. The licence category establishes the engineer’s technical scope at a basic level. The aircraft type rating identifies the specific aircraft for which the licence may be endorsed.

The practical sequence is:

• Obtain the relevant Part-66 basic licence category or subcategory.
• Complete aircraft type training where required.
• Complete on-the-job training (OJT) where required.
• Apply for the aircraft type-rating endorsement.
• Obtain the appropriate organisational authorisation from a Part-145 or other approved maintenance organisation.

The licence endorsement and company authorisation are separate requirements. A type rating on a UK Part-66 licence does not, by itself, grant unrestricted certification privileges within an employer’s maintenance organisation.

What does the B1.E category establish?

B1.E is intended to cover the relevant electric-powered aircraft maintenance scope under the applicable Part-66 framework. It should be treated as a specific licensing category, not as a generic approval to maintain every electrically propelled aircraft.

The aircraft types eligible for endorsement, applicable limitations and training route depend on the aircraft’s classification and the current UK CAA or EASA Part-66 requirements. Engineers should confirm the applicable aircraft type-rating list and licensing requirements with the UK CAA Part-66 guidance or the EASA aircraft maintenance licensing information before booking training.

The basic category demonstrates knowledge and experience at category level. It does not demonstrate that the holder has completed the aircraft-specific training, practical exposure and task competence required for a particular type. Engineers comparing licence routes may also benefit from our guide to obtaining a B1 E Part 66 licence.

When is aircraft type training required?

Aircraft type training is normally completed through an appropriately approved Part-147 training organisation where the type requires formal type training. The course may include:

• Aircraft systems and construction;
• Powerplant and propulsion systems, where applicable;
• Electrical energy storage and distribution systems;
• Flight controls and related mechanical systems;
• Avionics and aircraft electronic systems within the B1.E scope;
• Maintenance practices, procedures and safety precautions;
• Practical elements using the aircraft, approved training equipment or other accepted means.

Where type training is required, the applicant will normally need evidence of completing the approved Part-147 course. The Certificate of Recognition may cover both the theoretical and practical elements, provided the course was approved on that basis.

Under Part-66 Appendix III, aircraft type-rating training must have been started and completed within the three years preceding the application for the type-rating endorsement. This requirement is important when planning an application. Completing a course too early and then delaying the application beyond the permitted period may require the applicant to repeat or refresh the training.

The same principle applies where training is being used to support the removal of limitations from an existing type rating. The relevant training must comply with Part-66 Appendix III and must have been started within the required three-year period before the application.

When is OJT mandatory for B1.E?

For B1 and B2 licences, OJT is required where the aircraft is the first aircraft type in the relevant licence category or subcategory. This requirement is set out in Part-66 66.A.45(c), supported by the associated guidance material in GM 66.A.45. Applicants should verify the current rule and acceptable arrangements with the UK CAA or their applicable EASA competent authority.

For a B1.E licence holder, this means that the first aircraft type added to the relevant B1.E category or subcategory will generally require acceptable OJT in addition to the required type training. OJT is not simply an attendance record or a general period of employment. It must demonstrate practical maintenance experience on the aircraft type.

The OJT programme must be:

• Completed on the relevant aircraft type;
• Conducted in an appropriate maintenance environment;
• Structured and supervised by an approved organisation or other accepted arrangement;
• Recorded against defined maintenance tasks;
• Representative of the aircraft and its systems;
• Acceptable to the UK CAA or the applicable EASA competent authority.

The objective is to demonstrate that the applicant can apply the knowledge gained during type training to real maintenance activity.

What must B1.E OJT cover?

OJT must cover a representative cross-section of tasks acceptable to the competent authority. The tasks should reflect the aircraft type and the level of technical input expected from a B1.E engineer.

A suitable programme should not consist only of routine or low-complexity work. Although relatively simple tasks may be included, the programme should also incorporate more complex maintenance tasks where appropriate to the aircraft type. The balance will depend on the aircraft’s design, maintenance programme and the work available in the operating environment.

For an electric-powered aircraft, this may involve exposure to systems such as:

• High-voltage or high-energy electrical systems;
• Energy storage and battery installation systems;
• Propulsion motor and power-electronics interfaces;
• Electrical distribution and protection;
• Thermal management;
• Mechanical installation and structural interfaces;
• Flight controls, landing gear and other B1.E systems;
• Fault isolation, component replacement and functional testing;
• Maintenance precautions associated with stored electrical energy.

The task list must remain specific to the aircraft type. Generic experience on unrelated electrical equipment cannot automatically substitute for aircraft type OJT.

A well-controlled OJT record should identify the aircraft registration or serial number, task reference, date, work package, level of participation and supervisor or assessor. It should make clear whether the trainee observed, assisted with or performed the task under supervision.

CAP 741 records and evidence for a UK application

For a UK CAA application, practical experience and OJT evidence must be sufficiently detailed for the authority to assess it. CAP 741 logbooks and CAA guidance are commonly used to record aircraft maintenance experience. The logbook should be supported by employer records, task cards, training documentation and supervisor confirmation where necessary.

The quality of the evidence is more important than the number of entries. A list of repeated, simple tasks may not demonstrate the required breadth, whereas a properly documented cross-section of representative tasks can provide a clearer basis for assessment.

Applicants should retain:

• The Part-147 Certificate of Recognition;
• The approved OJT programme;
• Completed OJT task records;
• Supervisor and assessor sign-off;
• Aircraft and maintenance organisation details;
• Relevant employment or practical experience evidence;
• Any limitation-removal or differences-training documentation.

The CAA may need to verify that the OJT was performed on the correct type, covered suitable systems and involved sufficient technical participation. For practical guidance, see our articles on completing a CAP 741 logbook and avoiding common CAP 741 logbook mistakes.

First type, subsequent types and differences training

The OJT requirement is particularly important for the first aircraft type in the relevant B1.E category or subcategory. Subsequent aircraft type endorsements may follow a different route, depending on the applicable Part-66 requirements and the relationship between the aircraft types.

A differences course may be appropriate where the applicant already holds a related aircraft type rating or has completed the required type training for the aircraft from which the differences are being identified. Under Part-66 Appendix III, a type rating may only be endorsed following differences training where the applicant has either:

• The source aircraft type rating already endorsed on the licence; or
• Completed the type-training requirements, including both theoretical and practical elements, for the source aircraft.

Differences training is not a substitute for the prerequisite aircraft knowledge. The applicant must demonstrate that both the source type and the new type have been addressed in the manner required by Part-66.

Removing limitations from a B1.E type rating

A B1.E type rating may carry limitations that restrict the systems or maintenance scope the holder may certify. To apply for their removal, the applicant must hold a current and valid Part-66 licence with the relevant unrestricted basic category or subcategory.

The relevant basic category or subcategory must not itself contain limitations corresponding to those the applicant is seeking to remove. A type-rating limitation cannot normally be lifted if the underlying basic category still carries the same restriction.

The application will generally require appropriate training and practical maintenance experience. The training must comply with Part-66 Appendix III and meet the applicable validity period. Practical experience should cover the corresponding systems and be gained on operating aircraft.

For B1.E applicants, the evidence should show not only attendance at a course but also practical exposure to the systems affected by the limitation. The UK CAA will assess whether the training and experience demonstrate the required competence.

Recognition of previous experience and military service

Previous maintenance experience may be relevant to a B1.E application, but it must be documented and mapped to the applicable Part-66 requirements. Experience on electric systems in a military environment is not automatically equivalent to civil aircraft maintenance experience.

Former military engineers should use the appropriate UK Ministry of Defence and UK CAA recognition pathways. Military service records, trade qualifications, aircraft task records and competency assessments may support an application, but the authority must be able to establish the aircraft type, maintenance standard, task content and level of responsibility involved.

Where a military aircraft or system has no direct civil equivalent, additional civil type training, OJT or experience may still be required. Applicants should obtain an individual assessment rather than assume that military authorisations transfer directly to a UK Part-66 type rating.

From licence endorsement to certification privilege

After the B1.E type rating has been endorsed, the engineer is not automatically authorised to certify all maintenance on that aircraft. The employing Part-145 organisation must assess the engineer’s competence, recent experience, training and compliance with company procedures before issuing an organisational authorisation.

The organisation may also impose limitations based on the engineer’s experience, task exposure or the scope of its approval. Continued competence requires current experience, recurrent training where applicable and compliance with the organisation’s authorisation procedures. Our guide to keeping CAA and EASA Part-66 licences and type ratings current explains the wider continuing requirements.

For a B1.E engineer, the route after the basic licence category is therefore structured and evidence-led:

B1.E category, aircraft type training, first-type OJT where required, type-rating endorsement, organisational authorisation.

Understanding this sequence prevents a common licensing error, treating the basic category as the final qualification. In the UK and EASA systems, the category establishes the foundation, while type training, representative OJT and formal endorsement demonstrate competence on the aircraft the engineer will actually maintain.

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