EASA Part-66 B1 vs B2 Engineer: Careers Compared

Overview: B1 vs B2 at a Glance

The B1 engineer and the B2 engineer occupy complementary but distinct roles in aircraft maintenance. The primary difference is the domain: B1 engineers hold an EASA Part-66 mechanical licence authorising them to certify airframes, mechanical systems, and engines, while B2 engineers specialise in the electronic systems — communication, navigation, instruments, radar, autopilots, and digital data networks. Your choice between these paths will shape not only the aircraft systems you work on but also the employers you can work for and your long-term career trajectory.

B1 Engineer: The Broad Generalist

B1 engineers are the general practitioners of aircraft maintenance. They work on the physical structure of the aircraft — fuselages, wings, landing gear, flight controls — and on the engines that power it. This includes sheet metal and composite repairs, hydraulic system troubleshooting, landing gear overhaul, engine removal and installation, and the full range of scheduled inspections. B1 engineers work at flight schools, regional repair shops, corporate flight departments, MROs, and major airlines.

The B1 work is highly varied and hands-on — a B1 engineer might perform a daily check on an Airbus A320 one day and troubleshoot a hydraulic leak on a business jet the next. You develop a broad skill set across multiple aircraft types and systems, and you can see the direct impact of your work on aircraft operators and flight training organisations. As certifying staff under Part-145, the B1 engineer who performs, supervises, or inspects the work may sign the release to service — the legal authority that makes the B1 licence the central credential of the profession.

The B1 environment tends to involve larger physical work — pulling engines, replacing landing gear, repairing structures — and a wider variety of tools, from torque wrenches and rivet guns to composite curing equipment. Engineers who enjoy mechanical problem-solving, structural work, and hands-on craft thrive in this role.

B2 Engineer: The Electronics Specialist

B2 engineers specialise in the electronic systems that modern aircraft depend on: communication radios (VHF, HF, SATCOM), navigation systems (VOR, ILS, DME, GPS), transponders, weather radar, flight management systems, autopilots, and electronic flight instrument systems. The work is highly technical and precision-oriented — troubleshooting a faulty circuit board, testing an antenna installation, or loading software into a flight management computer.

B2 engineers qualify through the Part-66 B2 module set, which is built around M3 Electrical Fundamentals, M4 Electronic Fundamentals, M5 Digital Techniques/Electronic Instrument Systems, and M13 Aircraft Aerodynamics Structures and Systems. The "dual" engineer — B1 plus B2 — is a rare and highly sought-after combination because it combines mechanical breadth with electronics expertise and the authority to sign the release to service across the whole aircraft.

Modern aircraft contain exponentially more electronics than their predecessors. The A320neo and 737 MAX families have dozens of networked avionics systems, and the trend toward more electric aircraft and connected systems means demand for skilled B2 engineers continues to grow. Avionics work is generally less physically demanding than structural work and more focused on diagnostic problem-solving with schematics, oscilloscopes, and software tools.

Certification Requirements for Both Paths

The certification paths differ significantly:

• B1 engineer — Pass the 13-module B1 exam set (e.g., B1.1: M1-M10, M11, M14, M15, M17) with a 75% pass mark per module, complete 5 years of experience (3 with a recognised technical diploma, 2 with a recognised technician licence), and pass the assessment of competence (66.A.40).
• B2 engineer — Pass the B2 module set (M1-M10 plus M13 and M14) with a 75% pass mark per module, complete the same 5-year experience requirement (3 with a recognised diploma), and pass the assessment of competence.

For detailed preparation strategies and module breakdowns, see our EASA Part-66 module exams guide.

Experience Requirements: What Counts

B1 Experience Focus

Part-66 requires 5 years of practical experience for B1.1, B1.3 and B2 (4 years for B1.2, 3 years with a recognised technical diploma, 2 years with a recognised technician licence) per 66.A.30 — or completion of an MTO training programme, which reduces the period. The experience must involve the procedures, practices, materials, tools, and equipment generally used in maintaining aircraft, documented in a logbook countersigned by certifying staff.

B2 Experience Focus

B2 experience is typically gained on the job at an avionics shop, MRO avionics bay, or airline line station — bench work, aircraft installations, and system testing. The same 5-year requirement applies, and the logbook must demonstrate breadth across electrical and electronic systems. Many B2 engineers come from electronics backgrounds, military service, or technical college avionics programmes.

If you are unsure which path to pursue, one strategy is to start with the B1 — the broad certification keeps every door open — and add B2 (or the relevant B2 modules) as your interests crystallise. Many employers support cross-training, and having both skill sets makes you significantly more valuable.

How to Choose Between B1 and B2

Consider these factors carefully when deciding which path to pursue. Your choice should align with your career aspirations, geographic preferences, and personal interests:

• Career goals — If you dream of certifying aircraft and working hands-on with structures and engines, choose B1. If you want to specialise in the electronic brain of modern aircraft, B2 is the path. The combination — dual B1/B2 — is the most marketable of all.
• Job market geography — B1 jobs are everywhere: flight schools, GA airports, regional centres, and major hubs. B2 jobs are concentrated at avionics shops, MROs with avionics divisions, and airline technical operations at major airports. If you want to live in a smaller community, B1 offers more opportunities.
• Training availability — MTOs across Europe offer B1 and B2 programmes (with the module exams at the end). Avionics training is also available through technical colleges and employer-sponsored training. Research which programmes are available in your region.
• Upgrade path — You can start as a B2 engineer and add B1 later, or earn B1 first and specialise in avionics afterwards. The dual licence is a common goal for ambitious engineers.
• Salary expectations — Both paths pay comparably at entry level (€28,000–€40,000). Experienced B1 engineers at major airlines earn €55,000–€70,000+; senior B2 specialists earn similar ranges, with premiums for emerging technologies (SATCOM, advanced flight management, integrated modular avionics).
• Work environment — B1 work is physical and varied, in hangars and on flight lines. B2 work is cleaner and more diagnostic — bench work, schematics, and software. Think about which environment suits your work style.

Moving Between the Two Paths

Moving between B1 and B2 is a well-established career path. Many B2 engineers start with a B1 (or pursue it in parallel) because the mechanical licence provides the broadest certification authority. Conversely, many B1 engineers add B2 through additional modules and type training to become "one-stop" engineers capable of handling both mechanical and electronic discrepancies.

The dual B1/B2 engineer is particularly valuable at corporate flight departments and regional airlines, where a single engineer may need to troubleshoot a radar unit and then rig a flight control on the same aircraft. Employers consistently pay a premium for the combination.

Get Started with Skylicence Europe

Whether you are pursuing B1, B2, or the dual licence, Skylicence Europe covers the Part-66 module exam requirements with AI-powered adaptive learning. Our question bank contains 4,464 questions aligned to Part-66 Appendix I and includes full exam simulations for all 17 modules across all 8 licence categories. The AI adapts to your performance, identifying weak areas and generating targeted practice questions to maximise your study efficiency.

For a complete overview of the certification process, including eligibility requirements, training pathways, and the assessment of competence, read our complete guide to becoming an EASA Part-66 licensed engineer.

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