Aircraft and Space Vehicle Engineering Standards Summary - May 2025

Looking back at May 2025, the Aircraft and Space Vehicle Engineering sector saw the publication of five pivotal standards that collectively advanced best practices in digital data transmission, fiber optic cabling, change management, and electrical system design for aviation and space applications. These documents encapsulate a blend of incremental improvement and forward-focused adaptation, responding to the mounting pressures for reliability, safety, and digital transformation in aerospace. For professionals across engineering, quality, and compliance disciplines, this overview distills the key developments and highlights why staying abreast of these standards is essential.

Monthly Overview: May 2025

The month’s standardization activity in Aircraft and Space Vehicle Engineering reflected both continuity and evolution. Three major standards focused on advanced cabling—two for optical fiber and one for shielded Ethernet cabling—demonstrate the industry’s ongoing prioritization of high-speed, robust communications infrastructure. The publication of EN 9116 underscores the maturing emphasis on transparent configuration management and traceable change-of-design notifications, a must as globalized supply chains handle increasingly complex system interdependencies. Meanwhile, ISO/TR 25087 fills an essential knowledge gap, presenting analytical methodologies for electrical wire derating—highly relevant for the extreme environments faced in modern space systems. This pattern aligns with a sector-wide movement toward digitalization, data integrity, and risk-based safety management.

Compared to typical publication cycles, May 2025 stands out for its concentration on both detailed component specifications and overarching process control, providing organizations with both granular guidance and holistic frameworks to bolster compliance and innovation. The diversity and depth of these standards suggest an industry steadily moving toward integrated systems, performance-based requirements, and greater transparency in engineering decision-making.

Standards Published This Month

EN 3375-011:2025 – Lightweight Star Quad Ethernet Cable for Aerospace

Aerospace series – Cable, electrical for digital data transmission – Part 011: Single braid – Star Quad 100 ohms – Lightweight – Type KL – Product standard

EN 3375-011:2025 specifies the comprehensive product requirements for an AWG 24 shielded quad cable, Type KL, engineered for high-speed (100 Mbit/s) full duplex Ethernet networks in aerospace platforms. Its scope covers the cable’s dimensions, tolerances, required characteristics, and mass (≤32.4 g/m), as well as essential attributes such as laser markability (meeting EN 3838) and a characteristic impedance of 100 Ω ± 15 Ω. With a broad operating temperature range from –65 °C to 125 °C, this standard supports reliable data transmission in harsh aerospace environments.

The document provides detailed specifications for materials (silver-plated copper, fluoropolymer insulation and jacket), required performance tests (e.g., attenuation, crosstalk, voltage proof, flammability, accelerated aging), and quality assurance protocols. The 2025 revision introduces editorial improvements and an update making the cable filler optional, aligning further with installation flexibility and weight constraints.

This standard is relevant for aerospace manufacturers, avionics integrators, and organizations managing digital networks on aircraft or spacecraft—especially where weight, EMI shielding, and marking traceability are critical. It is a central part of the regulatory landscape placed alongside EN 3375-001/002 and the EN 3475 test series.

Key highlights:

• Sets physical, electrical, and environmental requirements for 100 Ω shielded star quad data cables
• Mandates rigorous testing (conductivity, insulation, flammability, etc.) for airworthiness
• Updated to improve installation options and reduce unnecessary mass

Access the full standard:View EN 3375-011:2025 on iTeh Standards

EN 4641-102:2025 – Semi-Loose GI Fibre Optic Cable (1.8 mm Outer Diameter)

Aerospace series – Cables, optical 125 μm diameter cladding – Part 102: Semi-loose 62.5 μm/125 μm GI fibre nominal 1.8 mm outside diameter – Product standard

EN 4641-102:2025 sets the product requirements, qualification, and quality assurance conditions for a semi-loose, graded-index (GI) optical fiber cable, featuring a 62.5 μm/125 μm core/cladding and a nominal outer diameter of 1.8 mm. This standard outlines mechanical and optical criteria—including attenuation limits, bend radius, tensile strength, and resistance to environmental factors—designed to ensure robust optical signal integrity in demanding aircraft and spacecraft installations.

The construction features a silica-based core and cladding, polyacrylate coating, and fluoropolymer jacket, selected for durability and low mass (≤4.65 g/m). The cable meets strict attenuation requirements (<4 dB/km at 850 nm, <2 dB/km at 1300 nm) and withstands operating temperatures from –65 °C to 150 °C. Extensive references to EN 3745 optical test methods underpin comprehensive validation for aerospace deployment.

Primary users are aerospace designers, avionics OEMs, and quality managers responsible for flight-critical optical networks. It fits within the broader framework of the EN 4641 series and is compatible with rigorous industry norms for data transmission and system safety.

Key highlights:

• Defines robust requirements for 1.8 mm semi-loose buffer GI optical cables
• Emphasizes quality assurance for critical avionics/databus applications
• Features material and marking guidelines to ensure identification and lifecycle traceability

Access the full standard:View EN 4641-102:2025 on iTeh Standards

EN 4641-103:2025 – Ruggedized Simplex GI Fibre Optic Cable (2.74 mm Outer Diameter)

Aerospace series – Cables, optical 125 μm diameter cladding – Part 103: Semi-loose, ruggedized simplex construction 62.5 μm/125 μm GI fibre nominal 2.74 mm, outside diameter – Product standard

EN 4641-103:2025 builds upon the technology of EN 4641-102 by specifying a ruggedized, simplex GI fiber cable with an increased outer diameter of 2.74 mm. Targeted at ultra-demanding environments where vibration, mechanical impact, and extended handling present risks, this standard prescribes qualification, acceptance, and quality assurance for cables based on the semi-loose EN 4641-102 base with additional protective sheaths.

Notable are the detailed mechanical reinforcement and material layers designed for enhanced durability without sacrificing signal fidelity. It rigorously addresses requirements for tensile strength, impact resistance, environmental exposures, and compatibility with standard aerospace connectors and termination techniques. The update draws a line between simplex and multimode fiber constructions, ensuring clarity for procurement and engineering functions.

Organizations in military aerospace, deep space, and harsh avionics environments benefit most from this standard, especially where maintenance cycles and operational disruptions must be minimized.

Key highlights:

• Specifies simplex GI fiber cable construction for maximum mechanical robustness
• Mandates expanded qualification tests for impact, abrasion, and environmental durability
• Facilitates integration into ruggedized, safety-critical aerospace subsystems

Access the full standard:View EN 4641-103:2025 on iTeh Standards

EN 9116:2025 – Notice of Change (NOC) for Aerospace Industries

Aerospace series – Notice of change (NOC)

EN 9116:2025 offers a comprehensive framework for communicating and managing changes in design or process across aviation, space, and defense supply chains. Reflecting the complexity of modern aerospace manufacturing—often spread globally and hierarchically among suppliers—this document standardizes Notice of Change (NOC) practices, ensuring that any modification, whether minor or major, is properly evaluated, notified, and archived for configuration control.

The standard specifies organizational requirements, roles (such as the Design Approval Holder), data set structure (paper or electronic), and procedural flows to ensure regulatory, contractual, and customer expectations are met. Special attention is paid to changes affecting certified aerospace or defense products, reinforcing the traceability and authority needed for safety and airworthiness. The 2025 revision streamlines requirements, updates guidance for digital workflows, and clarifies processes for multinational supply chains and export-controlled data.

EN 9116 is essential for design organizations, suppliers, and quality managers who handle product modifications at any tier. It is intended for contractual or voluntary invocation and aligns with the EN 9100 series and ISO 9000:2015 fundamentals.

Key highlights:

• Standardizes NOC process—covering requirements, data submission, and retention
• Strengthens traceability and risk management in design change scenarios
• Supports compliance with EN 9100, regulatory frameworks, and complex supply chains

Access the full standard:View EN 9116:2025 on iTeh Standards

ISO/TR 25087:2025 – Study of Electrical Wire Derating in Space Systems

Space systems – Study of electrical wire derating

ISO/TR 25087:2025 fills a critical knowledge gap by providing comparative analysis and guidance on electrical wire derating for space applications. In the severe, convection-less environments of space, correct wire sizing and current limitation are vital to prevent failure due to excess heating or radiation exposure. This technical report surveys prevailing governmental and industry standards—such as SAE AS 50881, MIL-STD-975M, NASA and ESA documents, and Japanese and Chinese agency guidelines—to illuminate differences in derating approaches for both single and bundled wires.

The report assists electrical designers in understanding allowable current calculation, the influence of ambient conditions, material selection, and insulation practices (e.g., polytetrafluoroethylene vs. ethylene tetrafluoroethylene). It contrasts various agencies’ methodologies for determining wire ampacity, derating factors, and best practices for wire placement and verification through thermal analysis. The result is a foundation for harmonizing design and improving safety margins in spacecraft system engineering.

This report is relevant for aerospace systems engineers, procurement specialists, and safety authorities involved in the specification or evaluation of electrical cabling for satellites, launch vehicles, and manned spacecraft.

Key highlights:

• Analyzes and compares international standards for wire derating
• Covers allowable current calculation for bundled and single wires under vacuum
• Supports risk-based design strategies for achieving optimal cable sizing in spacecraft

Access the full standard:View ISO/TR 25087:2025 on iTeh Standards

Common Themes and Industry Trends

Several cross-cutting themes emerge from May 2025’s standards:

• Data and Communication Backbone: Three of five publications address the physical infrastructure necessary for high-speed, high-integrity data transmission. This signals recognition of digital architectures as core enablers for advanced control, autonomous operations, and remote diagnostics in both aircraft and space vehicles.

• Resilience and Safety in Extreme Environments: New and revised fiber and electrical cable standards emphasize component reliability under harsh thermal, vibration, and radiation exposures, reflecting industry focus on both commercial and deep-space missions.

• Process and Change Management: The updated EN 9116 formalizes best practices for change notification and traceability, dovetailing with regulatory trends demanding robust documented control through the lifecycle. This theme supports risk reduction and regulatory compliance at every supply chain level.

• Risk-Informed Design Methodologies: ISO/TR 25087 bridges the gap between academic engineering knowledge and applied systems design, empowering organizations to make informed choices about wire specifications and their implications for mission safety.

• Alignment with Global Standards: The references to broad sets of industry and national documents across the standards illustrate the sector’s move toward global harmonization, reducing ambiguity and facilitating multinational projects.

Compliance and Implementation Considerations

Organizations affected by these standards should consider the following steps:

1. Gap Analysis: Review existing product and process specifications against the new or revised standard requirements. Pay special attention to cable attributes, marking protocols, derating factors, and procedural flows for change management.

2. Prioritize Compliance: For aircraft under development or in service, integrating compliant cables and notification processes early will decrease retrofit costs and airworthiness risks.

3. Training and Documentation: Engineers and quality personnel must understand new test procedures, qualification processes, and documentation formats specified (e.g., for NOC submission).

4. Timelines: The standards require implementation per contractual or regulatory deadlines, with November 2025 often cited for national adoption. Early scheduling of retesting or recertification is advised for ongoing projects.

5. Supplier Engagement: Communicate new requirements to all tiers of the supply base, particularly those involved in cable assembly, marking, or design change submission.

6. Resource Access: Full texts and guidance tools are available via iTeh Standards, facilitating continuous reference and staff training.

Conclusion: Key Takeaways from May 2025

May 2025 represents a significant period for Aircraft and Space Vehicle Engineering professionals, with five standards providing both fine-grained component guidance and overarching process controls. The spotlight falls on:

• High-reliability electrical and optical cabling enabling next-generation data systems
• Reinforced frameworks for documenting and approving design or process changes
• Analytical tools for safer, more effective electrical design in space extremes

For engineers, compliance officers, and procurement specialists, proactivity in adopting these standards will support safer, more efficient operations—while mitigating downstream risks and streamlining regulatory inspections. Early alignment and robust internal communication are essential to transform these formal publications into practical, operational excellence.

To dive deeper, explore each referenced standard at iTeh Standards, ensuring you and your teams are fully prepared for the evolving technical and compliance landscape.