Aviation Relay Certification Requirements Guide - Aviation Metal Relays

Aviation Relay Certification Requirements Guide: Navigating the Path to Airworthiness

For procurement managers and engineering teams supplying the global aerospace industry, selecting a relay is a decision governed by one paramount principle: airworthiness. Unlike commercial or industrial components, an aviation relay must be backed by a rigorous and often complex web of certifications that validate its safety, reliability, and traceability for use in Aircraft Engine controls, flight systems, and ground support. This guide demystifies the essential certification landscape, empowering B2B professionals to specify compliant components, streamline the approval process, and mitigate program risk from the supply chain up.

The Certification Hierarchy: From Design to Installation

Aviation certification is a multi-layered process. For a relay to be installed on an aircraft, it typically must satisfy requirements at three key levels:

1. Component-Level Qualification: The relay itself is tested and qualified to specific technical performance standards (e.g., RTCA/DO-160, MIL-PRF-6106).
2. Manufacturer Quality System Approval: The company producing the relay must operate under a recognized aerospace quality management system (e.g., AS9100).
3. Installation Approval: The airframe manufacturer or OEM integrates the certified relay into a larger system or line-replaceable unit (LRU), which then undergoes its own certification as part of the aircraft type certificate.

The Procurement Mandate: Verifying the Chain of Custody

Your responsibility extends beyond buying a part with a sticker. You must verify the complete certification pedigree: valid test reports from an accredited lab, traceability of materials, and evidence of production under an approved quality system. This due diligence is non-negotiable, whether sourcing a Military Metal Sealing Relay for a defense platform or a PCB Signal Relay for a commercial airliner's entertainment system.

Core Technical Standards: DO-160 and Beyond

Technical qualification is primarily demonstrated through compliance with environmental test standards. The global benchmark is RTCA/DO-160, "Environmental Conditions and Test Procedures for Airborne Equipment."

Key DO-160 Test Sections for Relays

• Section 4: Temperature & Altitude: Verifies operation during rapid temperature changes and at low-pressure high-altitude conditions.
• Section 7: Operational Shocks & Crash Safety: Tests for functionality after sudden impacts relevant to hard landings.

Validates performance under sinusoidal and random vibration profiles experienced in flight. This is critical to prevent contact chatter in relays controlling

sensors.
• Section 10: Humidity: Assesses resistance to moisture condensation and absorption.
• Section 11: Salt Fog & Sand/Dust: For equipment exposed to corrosive or abrasive environments.
• Section 16: Power Input: Tests tolerance to abnormal power conditions on the aircraft electrical bus.
• Section 18: Magnetic Effect: Ensures the relay's own magnetic field does not interfere with nearby instrumentation.

Supporting Performance Specifications

DO-160 defines the environmental test methods. The performance criteria are often drawn from other specs:

• MIL-PRF-6106: Frequently invoked for the electrical, mechanical, and life cycle requirements of relays in both military and commercial aviation.
• Customer-Specific Standards (CSOs): Major airframers (Boeing, Airbus, etc.) often have their own detailed component standards that supplement or tailor DO-160 and MIL specs.

The Quality System Foundation: AS9100

Technical compliance is meaningless without consistent manufacturing. AS9100 is the internationally recognized Quality Management System (QMS) standard for the aerospace industry. It mandates:

• Risk Management: Proactive identification and mitigation of supply chain and production risks.
• Configuration Management: Rigorous control of design changes and revisions.
• Traceability: Ability to trace every component back through production to its raw material batch.
• Foreign Object Debris (FOD) Prevention: Specific controls to prevent contamination.
• Special Processes: Validated and controlled processes for welding, plating, potting, etc.

Regulatory Agency Oversight: FAA, EASA, and Others

Understanding TSO, PMA, and ETSO

While relays are rarely certified as standalone "articles," understanding these terms is crucial:

• Technical Standard Order (TSO) / European TSO (ETSO): An FAA/EASA approval for a design that meets a specific minimum performance standard. Some relays may be sold as TSO/ETSO articles if they have a defined aviation function.
• Parts Manufacturer Approval (PMA): An FAA approval to produce a replacement part for an already certified aircraft. This is a common path for aftermarket and repair station suppliers.
• In Practice: Most relays are qualified to the underlying technical standards (DO-160, MIL-PRF-6106) and supplied under the manufacturer's AS9100 system. The airframe OEM then uses this data to support the aircraft's overall type certificate.

5 Critical Certification Scrutiny Points for Russian & CIS Aerospace

Procurement for Russian aviation projects (MS-21, Sukhoi Superjet, MiG/Helicopter upgrades) involves specific, stringent checks:

1. Interavia (IAC AR) Certification & GOST Standards: Mandatory approval from the Interstate Aviation Committee (IAC AR) and compliance with aviation-specific GOST standards (e.g., GOST RV, GOST MV), often in parallel with DO-160/MIL.
2. Material Certification from Approved Suppliers: All metals, plastics, and coatings must come from suppliers approved by Russian aviation authorities, with full chemical composition and physical property certificates.
3. Witnessed Testing at Accredited Russian Labs: For major programs, qualification testing may need to be witnessed or entirely conducted at test laboratories accredited by Rosstandart or the Russian Ministry of Defense.
4. Complete Russian-Language Documentation Package: Certification files, test reports, manuals, and process specifications must be translated and formatted to meet local regulatory submission requirements.
5. Proof of Supply Chain Independence & Cybersecurity: For sensitive applications, evidence that the design and manufacturing supply chain is free from components or software subject to foreign export controls that could impede support.

Industry Trends: Digital Compliance and Additive Manufacturing

The certification landscape is evolving with technology:

• Digital Logbooks and e-Certification: Moving away from paper certificates of conformity (C of C) to secure, blockchain-style digital records for full lifecycle traceability.
• Certification of Additive Manufactured (3D-Printed) Parts: New frameworks are being developed to certify relays or components with 3D-printed elements, requiring new methods for material qualification and process control.
• Cybersecurity Certification for Smart Components: As relays integrate more electronics for health monitoring, they may fall under new aviation cybersecurity regulations (e.g., DO-326A/ED-202A).

The Certification Journey: From Supplier Selection to Installation

A Step-by-Step Procurement Checklist

1. Define the Requirement: Determine the exact application (commercial, military, rotorcraft) and required certification level (DO-160G, MIL-PRF-6106 Rev S, etc.).
2. Supplier Pre-Qualification: Verify the supplier holds a valid AS9100 certificate and has experience with your target certifications. Audit their quality management system.
3. Request Certification Dossier: Obtain and review the complete qualification test report (QTR) for the relay model, including DO-160 test summaries and material certifications.
4. Validate Traceability: Ensure the supplier's processes guarantee lot traceability from your order back to the qualified design and materials.
5. Maintain Records: Keep the certification package for the life of the aircraft, as it will be required for continued airworthiness and any future repairs or modifications.

YM's Certified Ecosystem: Built for Aerospace Compliance

YM doesn't just manufacture relays; we engineer and produce within a fully certified framework. Our 50,000 sq.m. facility is AS9100D certified, with dedicated cleanrooms and production lines for aviation products. Our in-house test laboratory is equipped to perform the majority of DO-160 environmental tests, ensuring direct control and fast turnaround during qualification. Our R&D team includes specialists in aerospace materials and qualification pathways, whose work on advanced contact plating recently secured a new PMA for a legacy aircraft relay—demonstrating our commitment to supporting the entire lifecycle of aviation components, from new Plane programs to legacy fleet sustainment.

Frequently Asked Questions (FAQ)

Q1: What is the difference between "qualified to DO-160" and "tested to DO-160"?

A: This is a crucial distinction. "Tested to DO-160" means some tests were performed using DO-160 methods. "Qualified to DO-160" means the relay has undergone a complete, documented test program covering all applicable sections of the standard for its intended installation category (e.g., equipment in pressurized areas, non-pressurized areas, or external), and has passed all criteria. Always request the full qualification test report (QTR).

Q2: Can a relay certified for military use (MIL-PRF-6106) be used in a commercial aviation application?

A: Often, yes—it's an excellent starting point. MIL-PRF-6106 is extremely rigorous. However, commercial aviation may require additional specific tests from DO-160 (e.g., Magnetic Effect, Section 18) or compliance with specific CSOs from Boeing or Airbus. The relay would need to be evaluated against the commercial program's specific requirements. Many of our Military Metal Relay products form the basis for our dedicated aviation lines.

Q3: Who is ultimately responsible for the certification of the relay on the aircraft?

A: The legal responsibility lies with the aircraft manufacturer (OEM) holding the Type Certificate. They certify that every part on the aircraft meets the approved design. As a component supplier, YM's responsibility is to provide parts that are manufactured under an approved system (AS9100) and are compliant with the technical data (DO-160, etc.) upon which the OEM's design approval is based.

Q4: Are there certification requirements for relays used in drones (UAVs) or Solid State Relay for Drone systems?

A: Yes, and they are rapidly formalizing. For large drones operating in civil airspace, certification standards akin to manned aviation are emerging (e.g., leveraging DO-160). For military UAVs, MIL standards apply. The key is the airworthiness authority governing the drone's operation. As a procurement manager, you must identify the governing certification basis (FAA Part 107, EASA Light UAS, specific military airworthiness) and ensure component qualification aligns with it.

Key Standards and Regulatory Documents

A comprehensive certification strategy references these core documents:

• RTCA/DO-160G: Environmental Conditions and Test Procedures for Airborne Equipment.
• SAE AS9100: Quality Management Systems - Requirements for Aviation, Space and Defense Organizations.
• MIL-PRF-6106: Performance Specification for Relays (U.S. Military).
• FAA AC 20-152: Advisory Circular on RTCA Documents as Means of Compliance.
• EASA CM-CS-003: Certification Memorandum for acceptance of DO-160.
• GOST RV 51001-XXXX / GOST MV XXXX: Series of Russian military and aviation state standards

References and Regulatory Guidance

1. RTCA, Inc. (2010). *DO-160G, Environmental Conditions and Test Procedures for Airborne Equipment*. Washington, DC: RTCA.
2. International Aerospace Quality Group (IAQG). (2016). *AS9100D: Quality Management Systems - Requirements for Aviation, Space and Defense Organizations*.
3. Federal Aviation Administration. (2011). *AC 21-43: Production Approval and Surveillance Procedures*. FAA.