Introduction
This three-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
Day 1: EWIS Context, Regulatory Framework & Engineering Considerations
Module 1: Introduction to EWIS (Engineering Perspective)
- Course overview, scope, and structure
- Engineering acronyms & EWIS terminology
- Evolution of EWIS: design failures driving regulatory change
- Why engineers must prioritize EWIS in design phases
- Certification Case Studies and engineering takeaways:
– Swissair Flight 111 – material selection and flammability
– BA 737-436 (G-DOCH) – system segregation and wiring failure modes
– Fault-tolerant design decisions and their impact on approval
– EWIS related incidents due to improper segregation or documentation
Module 2: EWIS Regulatory Framework for Design Engineers
- ICAO, FAA, EASA drivers for EWIS regulation
- Detailed scope and objectives of CS-25 Subpart H
- The role of DOA under Part 21 in EWIS compliance & Takeaways for DOA engineers.
- Design Organization Approval (DOA) implications for EWIS
- EWIS considerations in type design, STC, and Managing design changes.
Module 3: Human Factors from a Design Integration Perspective
- 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
Day 2: Applied Design Practices & Environmental Protection
Module 5: Applied EWIS Design in the Part 21 Context
- Part 21 DOA obligations related to EWIS
- EWIS design lifecycle: from concept to certification
- EWIS cabin walk – validation of IFE system installation
- Mitigating HF & physical failure modes through routing and redundancy
Module 6: EWIS Standard Practices – Design Implementation
- Design-driven material selection (Environmental, Electrical and Mechanical)
- Routing principles: EMI avoidance, accessibility, and support
– Certification cases involving system installation and routing - Segregation and identification strategies for complex systems
- Design specification for ESDS and grounding practices
- Workmanship as an engineering responsibility (not just production)
- Design Consideration for pressurised and unpressurised area of the AC
- Design Consideration for high voltage (ex: 270VDC) 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
- ESD and P-STATIC: prevention by design
- HIRF: design zones and protection integration
- Lightning protection: path analysis, bonding, and component qualification
Module 8: Design Support for EWIS Inspection & Airworthiness (High-level information is enough)
- 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
Day 3: 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
- Differences in design philosophy between CS-23 and CS-25 aircraft
- Substantiation packages and design approvals involving EWIS
Module 10: Key FAA Advisory Circulars – Technical Impact
- Detailed engineering review of:
– AC 25.1703 – Surface exposure and accessibility
– AC 25.1705 – Fuel tank wiring and shielding
– AC 25.1707 – System interface requirements
– AC 25.1709 – Fire protection in design
– AC 25.981-1C – Ignition source prevention
– AC 25.869-1A, AC 25.1357-1A, AC 25.1362 – Supporting electrical safety - Harmonizing these ACs with EASA CS-25 guidance material
Module 11: EWIS Safety Assessment for Engineers
- EWIS safety analysis frameworks: FHA, FMEA, ZSA
- Safety documentation and its role in certification
- Interface with System Safety Assessments (SSA)
- New aircraft vs. retrofit analysis strategies
- Typical EWIS failure modes and mitigations
- EWIS inputs to the system 25.1309 analysis process
Module 12: Final Workshop & Technical Wrap-Up
- Group activity: develop a EWIS compliance strategy for a system
- Use of compliance matrices and technical documentation
- Final discussion, engineering Q&A, and feedback session
- Course review and completion certification
Target groups
This course is ideal for aerospace professionals engaged in aircraft electrical system design, modification, or certification.
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
3 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
