What is the EASA part 66 licence?
According to the COMMISSION REGULATION (EU) 2018/1142, of the European Union delivered and approved by the national aviation authorities in the European Union member states, no one is allowed to repair, inspect, certify work done on airplanes or airplane parts without an EASA part 66 licence.
There are various EASA part 66 Licenses:
Maintenance: of Sailplanes, Motorsglider, Balloons or Zeppelins CAT-L
Avionic: of Sailplanes, Motorsglider, Balloons or Zeppelins CAT-2L
Maintenance: airplanes under 2000 kg B3
Maintenance: of airplanes with Turbine engines A1 oder B1.1
Maintenance: of airplanes with Piston engines A2 oder B1.2
Maintenance: of helicopters with Turbine engines A3 oder B1.3
Maintenance: of helicopters with Piston Engines A4 oder B1.4
Avionic: B2 Licence