Action
This invitation to tender is based on Part 8. ‘‘Climate, Energy and Mobility’’ of the Horizon Europe Work Programme 2023-2024, which was published by the European Commission on 6 December 2022.
Through this Work Programme, the European Commission has entrusted the European Union Aviation Safety Agency (EASA) with the management of seven research actions with a total budget of EUR 8.5 million. This invitation to tender addresses the following action: ‘‘Evolutions of airworthiness standards for new aircraft structure designs using materials, processes, and advanced manufacturing methods’’.
Expected outcome
The primary goal of this project is to promote the environmentally beneficial use of bonded and sandwich structures in safety-critical aviation applications, emphasising high strength and stiffness-to-weight ratios, while ensuring that catastrophic failures are prevented. This is aligned with aircraft certification specifications (CSs) and EASA regulations, as well as with related acceptable means of compliance (AMC) and guidance material (GM).
Key objectives include:
- Addressing safety concerns targeted at avoiding failures due to:
- fatigue;
- manufacturing defects;
- environmental degradation;
- accidental damage.
- Response to industry incidents initiated to address issues observed in bonded- and sandwich-structure-related incidents, in alignment with industry and regulatory discussions, including:
- Composite Materials Handbook-17 (CMH-17) forums,
- European Plan for Aviation Safety (EPAS) 2023-2025, Volume II, Research Project (RES).0027 on ‘Sandwich-structured composites’,
- Consultation of EASA Certification Memorandum (CM-S-010) on ‘Composite Materials — Safe Design of Monocoque Sandwich Structures’.
- Incorporating recent developments building on industry advancements, such as:
- enhanced understanding of ground-air-ground (GAG) cycles and their impact on skin-core disbonding;
- ASTM standard development for Mode-1 dominated skin-core failure testing;
- design solutions for large passenger aircraft sandwich structures as per CMH-17.
- Expanding research scope investigating:
- practical detection methods for failure modes (e.g. weak bonds, shear core failure) that may degrade in service;
- strategies for continued airworthiness and detection applicable to composite structures, supporting consistency across the industry.
This research project will advance current research by addressing gaps and leveraging recent developments to enhance structural safety, including possible applications beyond large passenger aircraft.
Required output
The expected outcome is industry-supported content relating to the identified Tasks 1, 2, 3, and 4, allowing the development of further regulatory and industry guidelines (as is increasingly necessary with regard to developing ‘performance-based regulation’ (PBR) philosophies) for the safe design, manufacture, and in-service use of bonded and sandwich structures in increasingly critical applications.
- Task 1 — Provision of a “Current industry status report” addressing sandwich structure technology application and experience;
- Task 2 — Development of substantiated design solutions;
- Task 3 — Improvement of damage detection for typically difficult-to-detect damage;
- Task 4 — Development of hybrid-structure continued-airworthiness strategies;
- Task 5 — Conclusions, recommendations, implementation roadmap, and cost-benefit analysis; and
- Task CDS — Communication, dissemination, and stakeholder management.
Regulatory and guidance documents likely to benefit from this work include the following:
- EASA CM-S-005 Issue 1 ‘‘Bonded Repair Size Limits in accordance with CS-23, CS-25, CS-27, CS-29 and AMC 20-29’’;
- EASA CM-S-010 Issue 1 ‘‘Composite Materials - The Safe Design and Use of Monocoque Sandwich Structures in Principal Structural Element Applications’’;
- EASA AMC 20-29 ‘Composite Aircraft Structures’ (2010);
- SAE Composite Materials Handbook – 17 (CMH-17) – Disbond and Delamination Task Group;
- other regulatory continued-airworthiness documents (existing and/or new.
Call for tender
Check the Call for Tender for this Research Project
Contract duration: 36 months
Research Project details
This project will be funded from the European Union's Horizon Europe
research and innovation programme.
Consortium members
Technical University of Denmark (DTU)
NSE Composites B.V
Fraunhofer Institute for Microstructure of Materials and Systems
Università di Genova
At the contractor
Project Manager: Christian Berggreen, cber [at] dtu.dk (cber[at]dtu[dot]dk)
Technical Lead: Ralf Hilgers, ralf.hilgers [at] airbus.com (ralf[dot]hilgers[at]airbus[dot]com)
At EASA
Project Manager: Helder Mendes, helder.mendes [at] easa.europa.eu (helder[dot]mendes[at]easa[dot]europa[dot]eu)
Technical Lead: Simon Waite, simon.waite [at] easa.europa.eu (simon[dot]waite[at]easa[dot]europa[dot]eu)