Skip to content
MaintenanceCrew
FR|EN

Guides

EWIS: electrical wiring interconnection system

The electrical wiring interconnection system (EWIS): why it has dedicated training and good shop practices.

What it covers

EWIS (Electrical Wiring Interconnection System) covers wires, connectors, terminal blocks, protections and fasteners. Airworthiness requirements are in CS-25 Subpart H, and AMC 20-22 describes an EWIS training programme for maintenance staff.

Good practices

  • Protect wire bundles during nearby work (drilling, cutting, welding).
  • Check for swarf, fluid contamination and chafing.
  • Follow bend radii, routing and clamping set out in the maintenance data.
  • Use the prescribed, calibrated crimping and stripping tools.

Frequently asked questions

Is EWIS training mandatory?

The need and level of training depend on the organisation and the tasks. Refer to AMC 20-22 and your organisation's procedures.

General information only. It does not replace the EASA regulatory texts, your organisation's exposition (MOE/MTOE) or the instructions of your competent authority.