The Importance of Electrical Wiring Interconnect System (EWIS) Practical Training
Sofema Online (SOL) www.sofemaonline.com Considers the Importance of Electrical Wiring Interconnect System (EWIS Practical Training to support the Competence Development of Aircraft Inspectors.
Introduction
Following investigations in the aftermath of Flight TWA800 and Swissair 111, a detailed investigation was performed by the Ageing Transport System Rulemaking Advisory Committee ATSRAC into the effectiveness of the Inspection Process carried out during maintenance activities.
After some years of Investigation, it was understood that there were a number of shortcomings observed which has translated into the need for specific training to manage electrical wiring inspection standards.
Protect & Clean As You Go
A new phase has been coined which should be shared amongst the workforce and fully adopted as a mantra which MUST be followed -
EWIS Maintenance Practice should include “Protect and Clean as You Go” (to ensure all possible contaminants are removed at source)
Overcoming the Challenges of Visual Inspection
When we consider the challenges of Electrical Wiring Interconnect System Inspection Standards we should also appreciate that there are limitations as to the effectiveness of the Visual Inspection process.
Sofema Online (SOL) www.sofemaonline.com Considers the Importance of Electrical Wiring Interconnect System (EWIS Practical Training to support the Competence Development of Aircraft Inspectors.
Overcoming the Challenges of Visual Inspection
When we consider the challenges of Electrical Wiring Interconnect System Inspection Standards we should also appreciate that there are limitations as to the effectiveness of the Visual Inspection process
» So every effort should be made to support the most effective methods possible.
» The most effective EWIS organizational standard provides for a combination of techniques including
o Visual
o Additional maintenance practices
o Improved training including
o Practical training inspection techniques specifically for EWIS Inspectors.
GVI Pre-Requisite
To deliver a General Visual Inspection (GVI) during EWIS Inspections requires we are within touching distance Note that this is actually a pre-requisite (unless otherwise specified).
The GVI may be supported by the use of a mirror which may be necessary to ensure visual access to all exposed surfaces in the inspection area.
» Regarding lighting requirements, it is normal for the inspection to be made under existing or normally available lighting.
» Some general considerations and observations to pay attention to during your inspection of aircraft EWIS
» Wiring Looms that are not supported can sag and incorrect use of tie wraps within the loom can cause chafing and in fact, tie wraps should be around the entire loom
» P Clip Migration – all P Clips should be of the correct size and firmly attached to the entire loom Tie Wraps can age harden fatigue and fail – pay particular attention during Inspection
» Any point of contact can allow wiring to chafe – so pay close attention during your inspection
Remember Human factors and effective inspection – take frequent breaks during the inspection –focus 100% on what you see. Share what you find with colleagues – raising the standard.
» It is most important to ensure that all clips secure the cables effectively otherwise chafing can occur
» No pressure should exist between electrical p clips and fittings – fixtures, pipes, or tubing
» The integrity of sleeving designed to prevent the ingress of fluids and moisture into connectors must be ensured
» P Clips must be correct IAW IPC or other approved data and must afford appropriate support and protection, oversize P Clips pose a threat.
For additional guidance on inspection please refer to the following document https://sassofia.com/wp-content/uploads/2014/10/Electrical_Wiring_Inspection_Observations.pdf
Next Steps
About Sofema Aviation Services (SAS) www.sasssofia.com
Sofema Aviation Services delivers EWIS Practical Training and Practical Training For Trainers to the highest standards on your own aircraft.
For details of available training please email team@sassofia.com
So every effort should be made to support the most effective methods possible.
» The most effective EWIS organizational standard provides for a combination of techniques including
o Visual
o Additional maintenance practices
o Improved training including
o Practical training inspection techniques specifically for EWIS Inspectors.
