Introduction
This four-day course, Electrical Wiring Interconnection System (EWIS) and FAA-EASA Part 23-25 Certification, provides an in-depth engineering-focused exploration of EWIS design and regulatory compliance. With increasing regulatory scrutiny and the complexity of modern aircraft systems, understanding EWIS is essential for safe and certifiable aircraft design. Through technical modules, real-world case studies, and interactive workshops, participants will gain the knowledge needed to integrate EWIS into compliant aircraft systems from initial design through certification. The course emphasizes both CS-23 and CS-25 requirements with a strong focus on FAA/EASA harmonization and engineering accountability.
Who is the Course for?
This course is tailored for design engineers, certification engineers, and technical managers involved in aircraft system development and modification. It is also relevant for those working under Part 21 Design Organization Approval (DOA) seeking to deepen their understanding of EWIS compliance.
What is the Benefit of this Training – What will I learn?
a) Understand the regulatory framework, engineering principles, and compliance drivers behind EWIS design and certification.
b) Integrate EMI protection, human factors, and system segregation strategies into EWIS design for both new and retrofit aircraft programs.
c) Incorporate environmental, physical, and operational considerations into wiring layout to ensure airworthiness and performance reliability.
d) Conduct EWIS-specific safety assessments-including FHA, FMEA, and ZSA-and align results with overall system risk profiles.
e) Develop substantiation packages and certification documentation using industry tools, FAA Advisory Circulars, and structured compliance workflows.
Detailed Content / Topics – The following Subjects will be addressed
EWIS Context, Regulatory Framework & Engineering Considerations
Module 1: Introduction to EWIS (Engineering Perspective)
Course Overview
Engineering Acronyms & EWIS Terminology
CS 25 Subpart H Electrical Wiring Interconnect Systems (EWIS)
Evolution of EWIS – Design Failures Driving Regulatory Change
Why Design Engineers must prioritise EWIS in Design Phases
EWIS Certification Case Studies and Engineering Lessons:
TWA 800, Swissair Flight 111, BA 737-436 (G-DOCH)
EWIS related incidents due to improper segregation or documentation
Material Selection and Flammability Considerations
System segregation and wiring failure modes – Fault-tolerant design decisions
Module 2: EWIS Regulatory Framework for Design Engineers
ICAO, FAA, EASA drivers for EWIS regulation
The Role of DOA under Part 21 in relation to EWIS Compliance – Additional DOA Responsibilities – Dedicated EWIS Compliance Plan
Module 3: Human Factors from a Design Integration Perspective
Design Organization Approval (DOA) – EWIS considerations in type design, STC, and Managing Design Changes.
Incorporating HF into EWIS Design to Prevent Maintenance Error
Layout, Accessibility, and System Separation to Support HF Needs
Safety Culture in Design Environments & Design Decisions that Either Reduce or Amplify HF-Related Risk
Module 4: Engineering View of EWIS in Aircraft Systems
Technical Definitions & Functional Components of EWIS, Zonal Decomposition and its impact on EWIS layout
EWIS Areas of Concern (AOCs): proximity to heat, fluids, vibration zones, Design for housekeeping: minimizing contamination & physical damage
Module 5: Applied EWIS Design in the Part 21 Context
EWIS cabin walk – validation of IFE system installation
Applied Design Practices & Environmental Protection
Module 6: EWIS Standard Practices – Design Implementation
Design-driven material selection (Environmental, Electrical and Mechanical)
EMI Avoidance, Accessibility, Support, and Mitigating HF & Physical Failure Modes through Routing and Redundancy
Segregation and identification strategies for complex systems, Design specification for ESDS and grounding practices
Certification cases involving system installation and routing
Workmanship as a Design Engineering Responsibility
Design Consideration for pressurized and unpressurised areas – High Voltage Wiring Design
Module 7: Electromagnetic Effects – Engineering Safeguards
EMI Sources and Shielding Strategies – Ensuring EMC Through Proper Layout, Filtering, and Testing
Electrical Bonding as a Design and Certification Factor – HIRF: Design Zones and Protection Integration
ESD and P-STATIC: Prevention by Design – Lightning Protection: Path Analysis, Bonding, and Component Qualification
Module 8: Design Support for EWIS Inspection & Airworthiness
(High-level overview)
Engineering Considerations for Ease of Inspection – Recognizing Common Defect Patterns During Design Review
Use of inspection checklists and data in the design phase & Traceability of EWIS compliance within design documentation
Certification, Compliance Strategy and Workshop
Module 9: Certification Requirements – Engineering Responsibilities
Certification Roadmap for EWIS Elements – Design and Documentation Techniques to Support Compliance
EASA/FAA Certification Documentation: Test Reports, Compliance Sheets
Integrating EWIS Compliance into System-Level Certification & Substantiation Packages and Design Approvals Involving EWIS
Responsibilities of the DOA in Obtaining Approval for Modifications Concerning EWIS
Differences in Design Philosophy Between CS-23 and CS-25 Aircraft
Module 10: Key FAA Advisory Circulars – Technical Impact
Key FAA Part 25 Regulations For EWIS – for Reference :
25.1701-1 – Compliance with 14 CFR Part 25, Subpart H, concerning EWIS.
25.1703 – Function and installation: EWIS.
25.1705 – Systems and functions: EWIS.
25.1707 – System separation: EWIS.
25.1709 – System safety: EWIS.
25.1711 – Component identification: EWIS.
25.1715 – Electrical bonding and protection against static electricity: EWIS.
25.1717 – Circuit protective devices: EWIS
25.1719 – Accessibility provisions: EWIS.
Module 10: Key FAA Advisory Circulars – Technical Impact – continued
25.1721 – Protection of EWIS.
25.1723 – Flammable fluid fire protection: EWIS.
25.1725 – Powerplants: EWIS.
25.1727 – Flammable fluid shutoff means: EWIS.
25.1729 – Instructions for Continued Airworthiness: EWIS.
25.1731 – Powerplant and APU fire detector system: EWIS.
25.1733 -Fire detector systems, general: EWIS.
AC 25.981-1C – Ignition Source Prevention Overview
AC 25.869-1A, AC 25.1357-1A, AC 25.1362 – Harmonizing with EASA CS-25 guidance material
Module 11: EWIS Safety Assessment for Engineers
Differences in Design Philosophy Between CS-23 and CS-25 Aircraft
Safety Documentation and its Role in EWIS Certification – Interface with System Safety Assessments (SSA)
EWIS safety analysis frameworks: FHA, FMEA, ZSA
Typical EWIS Failure Modes and Mitigations
EWIS Inputs to the System 25.1309 Analysis Process
New Aircraft vs. Retrofit Analysis Strategies
Module 12: Final Workshop & Technical Wrap-Up
EWIS Workshop Training Task – Group Activity – Develop a EWIS Compliance Strategy for SATCOM & Wi-Fi Installation in a CS-23 Aircraft
Reference the Previous Workshop Task – Consider the use of Compliance Matrices and Technical Documentation
Final Discussion, Engineering Q&A, and Feedback Session
Pre-requisites
Participants should have a basic understanding of aircraft systems and familiarity with certification principles.
Learning Objectives
- Apply EWIS design principles under EASA Part 21, addressing layout, IFE integration, and system-level risks.
- Implement routing, segregation, and installation strategies to ensure EWIS integrity and compliance.
- Design EWIS systems to resist EMI and environmental threats using shielding and bonding techniques.
- Enhance maintainability and inspectability through effective EWIS design and documentation.
- Support CS-23 and CS-25 certification by understanding engineering responsibilities and compliance pathways.
What do People Say about Sofema Aviation Services Training?
“This training offers very good explanations of difficult topics.”
“All aspect were useful, the examples were great.”
“This training helped me to develop some new skills.”
“The instructor is very resourceful and intelligent.”
“Having a visual material helps a lot the learning process.”
Duration
4 days – To commence at 09.00 and finish at 17.00, with appropriate refreshment breaks.
To register for this training, please email [email protected] or Call +359 28210806
