The Aircraft Maintenance Engineer Profession

What does an aircraft maintenance engineer do?

An aircraft maintenance engineer (AME) is responsible for the continued airworthiness of commercial and business aircraft. The role covers inspection, testing, repair, overhaul, and modification of every system on board — from engines and hydraulics to avionics, flight controls, and cabin systems. Engineers work in airlines, MRO (maintenance, repair, and overhaul) facilities, ground handling companies, and charter operators. Because aircraft operate globally, qualifications issued under EASA Part-66 are recognised across all EU member states and in many countries beyond.

The work spans two primary environments. Line maintenance takes place at airports between flights: pre-flight inspections, troubleshooting defects reported by flight crew, rectifying faults within tight turnaround windows, and certifying the aircraft ready for its next departure. Base maintenance is performed in hangar facilities during scheduled heavy checks — major structural inspections, component overhauls, and modifications that require the aircraft to be taken out of service for days or weeks at a time.

Regardless of environment, the central obligation of a licensed engineer is the same: to ensure that every aircraft released to service meets its approved maintenance data, its type certificate requirements, and the airworthiness standards mandated by the applicable authority.

Licence categories

EASA Part-66 defines four licence categories. Each authorises different work and carries different levels of responsibility. The category you hold determines what you can certify independently and what type ratings you can add to your licence.

Category	Title	Scope of authorisation	Typical route in
A	Mechanic	Line maintenance tasks under the direct supervision of a B1 or B2 certifying engineer. Cannot sign independent maintenance releases. Scope is limited to specific tasks listed in the maintenance organisation's authorisation.	Basic training (A1 / TA1 category) + on-the-job experience under a Part-145 organisation
B1	Technician-Mechanic	Certifying release to service after mechanical maintenance — structures, engines, mechanical systems, and avionics tasks that do not require in-depth avionics testing. The most common category in commercial airline line maintenance.	Part-147 basic training (B1.1 turbine aeroplanes) + 17 Part-66 module examinations + 2 years on-the-job experience + type rating
B2	Technician-Avionics	Certifying release to service after avionics and electrical maintenance — flight management systems, autopilot, navigation systems, communications, and in-flight entertainment. Increasingly important as aircraft become more software-defined.	Part-147 basic training (B2 / TB2) + module examinations + 2 years experience + type rating
C	Base Maintenance Engineer	Certifying release to service for base maintenance tasks (heavy checks, major modifications). Category C requires prior holding of B1 and/or B2 for at least 5 years on aeroplanes above 30 tonnes. Typically a senior management-track role in MRO or airline technical departments.	Minimum 5 years as B1 or B2 certifying engineer on large aeroplanes, with demonstrated base maintenance experience

For most career entrants, the target is B1 (turbine aeroplanes) — the largest segment of the job market and the licence that unlocks independent certifying authority on every major commercial aircraft type. B2 is the natural path for those with a background in electronics, avionics, or electrical engineering. Both categories are fully covered by TRITECH's Part-147 approval.

Why is demand so high?

The global commercial fleet is projected to double over the next twenty years. Boeing and Airbus both publish annual workforce outlooks that consistently forecast a shortage of tens of thousands of qualified maintenance technicians in the coming decade, with the shortfall particularly acute in Europe, the Middle East, and Asia-Pacific. Several factors compound the structural demand:

• Fleet growth is irreversible. Both Airbus and Boeing carry order backlogs measured in thousands of aircraft. Every new airframe requires trained engineers to maintain it throughout a service life that typically spans twenty-five or more years.
• Retirements are accelerating. A large cohort of licensed engineers who entered the profession in the 1990s and 2000s are approaching retirement age. The pipeline of newly licensed engineers is not yet large enough to replace them at pace.
• The work cannot be automated or offshored. Physical inspection, hands-on rectification, and the legal act of signing a Maintenance Release require a licensed individual physically present at the aircraft. Unlike many technical roles, this work is inherently location-bound.
• Regulatory barriers protect the profession. The requirements to obtain an EASA AML are substantive — thousands of hours of training, multiple examinations, and significant on-the-job experience. This is not a credential that can be quickly issued, which creates sustained scarcity of qualified personnel.
• Low-cost carrier expansion in Europe. The continued growth of budget airlines across the continent has accelerated demand for B1-qualified engineers who can certify line maintenance releases at airports that previously saw little commercial traffic.

For individuals entering the profession now, the employment outlook is among the most favourable of any technical trade. Major European airlines and MROs are actively competing for newly licensed engineers with A320 family or B737 NG type ratings, and starting salaries have risen significantly as a result.

Career progression

The path from initial training to independent certifying authority follows a defined sequence set by EASA Part-66 and Part-147. There are no shortcuts — each stage builds on the last. The typical timeline from starting basic training to holding a B1 AML with a type rating is three to four years, depending on training intensity and the availability of on-the-job experience positions.