Ewis Leader

Labinal is a world leader in EWIS (Electrical Wiring Interconnection Systems). To answer inquiries in this field, whether from airframe manufacturers or airlines, it has a whole network of experts working together as a team.

We are proud to be the first company to manufacture and install a wiring system fulfilling all the requirements of fully-fledged EWIS.

Discover what EWIS is in detail

Having dispensed with mechanical-hydraulic back-up, all new aircraft are now endowed with full electrical control. This means that electrical installation has now, for the first time, been recognized as a complete system in its own right with the wiring specialist now seen to be a major contributor to the aircraft. Thus, for the electrics, all different physical failure modes have to be considered in safety analysis as for the other general systems (hydraulics, fuel, air-conditioning, etc.).

EWIS is the result of a pragmatic approach implemented within the framework of the ASTRAC (Aging Transport Systems Rulemaking Advisory Committee) Group.

EWIS regulation under EASA came into effect in September 2008 and becomes applicable for the first time on the Airbus A350. EWIS was introduced through FAR 25 – PART 25 and new subpart H. The scope of EWIS covers all electrical components installed in any area of the airplane with the purpose of conveying electrical energy, data and signals.

EWIS Regulation and requirements concern:

Installation and operation
The general aim with EWIS is to design a more “robust” electrical installation endowed with fault-tolerant behavior capable of withstanding damage during in-flight service and facilitating maintenance operations.

Every EWIS component installed in any A/C area must respect the following criteria:
  • Design (the element must be capable of performing its intended function)
  • Installation (must be in accordance with the limitations specified for EWIS components)
  • Design & Installation (performed in such a manner as to minimize mechanical stresses)
  • Security (ensure the role for which it was intended without impairing the airplane’s airworthiness).
    The selection of wires must minimize any risk of damage (especially the likelihood of arc-tracking) and tolerate a reasonable degree of deformation while minimizing any hazardous effects due to adverse environmental conditions.

Systems and functions
EWIS related components must be investigated and evaluated in accordance with the applicable requirements of the new FAR 25 - PART 25 subpart H.

System Separation
Each EWIS must be designed and installed with adequate physical separation (separation distance or barrier providing protection equivalent to the separation distance) to protect against electrical arc build-up from other EWIS and airplane systems to ensure that any EWIS component failure will not create a HAZARDOUS CONDITION.

System Safety
EWIS must be designed and installed so that:
  • Any catastrophic failure condition is extremely improbable and will not result from a single failure (<10-9 /flight hour)
  • Any hazardous failure condition is extremely remote (<10-7 /flight hour)

Component Identification
EWIS must be appropriately labeled or identified to facilitate ready recognition of the EWIS component concerned, its function and design limitations.

Fire Protection
EWIS must not fail in such a way as to propagate fire and produce hazardous quantities of smoke and toxic fumes. EWIS components must not cause harmful or hazardous concentrations of gases or vapors.

Electrical Bonding and Protection against Static Electricity
The application of EWIS regulations is intended to protect the airplane and personnel from electrical hazards or damage and injury.

Circuit Protection Devices
Dedicated rules to ensure compatibility of wires and circuit protection devices must be implemented.

Accessibility Provisions
Access must be provided to allow for inspection and replacement of any EWIS component as may be required to ensure continued airworthiness.

EWIS Protection
Requirements to prevent damage to EWIS by passengers, crew members, baggage handlers, maintenance and service personnel, or the movement of cargo or baggage have now been defined.

Flammable Fluid Fire Protection
EWIS components located in each area where flammable fluid or vapors might escape by leakage of a fluid system must be considered to be a potential source of ignition.

Powerplants
EWIS associated with any powerplant must be designed and installed such that:
  • the failure of an EWIS component on one powerplant will neither prevent the continued safe operation of the remaining powerplant(s) nor require immediate action by any crewmember for continued safe operation.

Design precautions must be taken:
  • to minimize hazards to the airplane due to EWIS damage in the event of a powerplant rotor failure or a fire originating within the powerplant that burns through the powerplant case.

Flammable Fluid Shutoff
Any EWIS working with a flammable fluid shutoff or control system must be fireproof or must be located and protected such that any outbreak of fire in a fire zone will not in any way impair operation of the said shutoff system.

EWIS Background & History Following the TWA Flight 800 (July 17, 1996) and Swiss Air Flight 111 accidents, the FAA set up a working group called ATSRAC (Aging Transport Systems Rulemaking Advisory Committee). This group focuses on inspecting wire damage or degradation over time. Inspections were conducted in aircraft graveyards and the group reached the conclusion that traditional ways of addressing airplane wiring no longer provided the level of safety expected by the regulatory agencies.

In October 2007, the FAA acted on a recommendation from ATSRAC and published FAR 25 Part 25 containing regulation and guidelines. The Airbus A350 will be the first airplane officially designed to the new EWIS regulation. The Boeing 787 also took the regulation into account, even though it was not yet mandatory.