✈️ PD IEC TS 62239 is the BSI-adopted IEC/TS 62239 series for process management for avionics — management plan. The two parts in this batch are Part 1, which covers the preparation and maintenance of an electronic components management plan (ECMP), and Part 2, which covers the preparation and maintenance of an electronic COTS (commercial off-the-shelf) assembly management plan. Both are handled by BSI Technical Committee GEL/107 (Process management for avionics); Part 1 supersedes the withdrawn PD IEC/TS 62239-1:2012. Working alongside standards such as IEC 62240 (component management), the series guides aviation manufacturers and their supply chains to build systematic, traceable, sustainable component and assembly management, ensuring long-term reliability and maintainability of airborne electronic equipment in harsh environments.
💡 Component failure and obsolescence are core risks to fleet sustainment: a single in-production chip suddenly going end-of-life can force a whole avionics system redesign. ECMP and COTS management plans are the process tools designed for “life-cycle supply assurance”.
1. Series Composition and Scope 📌
| Standard | Title | IEC Edition | Core Content |
| PD IEC/TS 62239-1:2015 | Process management for avionics — Management plan — Part 1: Preparation and maintenance of an electronic components management plan | IEC TS 62239-1 (Ed.2.0, 2015-04) | Component selection/application/qualification, supply chain, reliability, ECMP preparation and maintenance |
| PD IEC/TS 62239-2:2017 | Process management for avionics — Management plan — Part 2: Preparation and maintenance of an electronic COTS assembly management plan | IEC TS 62239-2 (Ed.1.0, 2017-02) | COTS assembly selection/application/compatibility, design assurance, heat dissipation and cooling, plan preparation |
⚠️ This series is a “process” standard: it specifies how the management plan is prepared, organised, and maintained, not the performance of any specific component. Actual component selection still references product standards such as IEC 62240 and ASD-STAN.
2. Part 1: Electronic Components Management Plan (ECMP) 📋
The ECMP is the management document by which an avionics system selects, applies, qualifies, and controls all electronic components used during development and production. Key technical requirements of Part 1 include:
- Component selection: application conditions (electrical, thermal, mechanical, environmental), availability and durability, additional performance requirements, and component identification.
- Component application: application rules for electromagnetic compatibility (EMC), stress derating, and thermal design, so components operate within allowable stress.
- Qualification: component qualification and batch acceptance requirements for consistent quality.
- Supply chain and procurement: sourcing channels, incoming inspection, and traceability.
- ECMP preparation and maintenance: plan document structure, content, version control, and continuous update mechanism.
Through the ECMP, a manufacturer can uniformly manage the selection, derating, and supply risk of thousands of component types, making it an important supporting document for airworthiness certification.
3. Part 2: Electronic COTS Assembly Management Plan 🧩
To reduce cost and development time, avionics increasingly uses commercial off-the-shelf (COTS) assemblies. Part 2 addresses the specific management requirements of COTS assemblies:
- COTS assembly selection: design assurance requirements, selection process, and suitability assessment.
- COTS assembly application: requirements for functionality, assembly compatibility, assembly materials, and heat dissipation and cooling.
- Environment and reliability: additional qualification of commercial assemblies for harsh avionics environments (vibration, temperature, humidity, high altitude).
- Plan preparation and maintenance: content and maintenance of the COTS management plan, covering component changes, obsolescence, and substitution management.
🚨 COTS assemblies are not designed for the avionics environment: their temperature ratings, vibration limits, and failure modes may not match airborne conditions. Part 2 requires additional environmental verification and derating of COTS assemblies — never install them without assessment.
4. Summary of Key Technical Requirements 🔧
| Topic | Key Requirement | Document |
| Component selection | Application conditions, availability, durability, identification | 62239-1 |
| Component application | EMC, stress derating, thermal design | 62239-1 |
| Qualification & procurement | Qualification, batch acceptance, traceability | 62239-1 |
| COTS selection | Design assurance, suitability assessment | 62239-2 |
| COTS application | Compatibility, materials, heat dissipation and cooling | 62239-2 |
| Plan maintenance | Version control, change and obsolescence management | 62239-1 / -2 |
5. Engineering Practice 🛠️
- 🔍 Airworthiness support: present the ECMP as part of airborne equipment design assurance, demonstrating to the certification authority that component management is controlled.
- 🔧 Supply-chain risk control: use the ECMP to track end-of-life (EOL), substitution, and counterfeit risk, planning secondary sourcing and redundancy purchases in advance.
- 📊 Derating and thermal review: review component stress derating per Part 1 application rules and assess COTS assembly heat dissipation and cooling per Part 2.
- 📋 Change management: update the management plan and re-evaluate on component or supplier change, keeping documents consistent with hardware.
6. Frequently Asked Questions ❓
❓ Q: What is an ECMP?
A: The ECMP (Electronic Components Management Plan) is a document that systematically manages the selection, application, qualification, procurement, and control strategy for all electronic components used in an airborne electronic system — a foundational tool of avionics process management.
❓ Q: Why do COTS assemblies need a separate management plan?
A: COTS assemblies are manufactured to commercial standards, not optimised for harsh avionics environments, and their supply chain and life cycle are market-driven. A separate plan forces assessment of suitability, environmental capability, and supply continuity, avoiding direct risk introduction.
❓ Q: Why is derating important in avionics?
A: Operating components below their rated stress significantly improves reliability and life, and is the first line of defence against environmental transients and ageing. Part 1 makes stress derating a key application rule.
🔍 Q: How is component end-of-life (EOL) handled?
A: The ECMP should define obsolescence warning and substitution processes, including last-time buy, replacement selection, re-qualification, and design change. Part 2 likewise requires obsolescence and substitution management for COTS assemblies to guarantee life-cycle supply.