SealedwithoUTaKiss · Project

Detecting Hidden Defects in Aircraft Composite Bonds Without Destroying the Part

transportTestedTRL 6

Imagine gluing two pieces of carbon fiber together for an airplane wing, but the glue looks perfect on the surface while secretly not sticking at all — like two smooth surfaces just kissing without actually bonding. That invisible flaw is called a "kissing bond," and it can cause structural failures. This project built inspection tools using laser shocks and special sound waves that can detect these hidden defects without cutting the part open. Think of it as an ultrasound scan for airplane joints — you see what's wrong inside without breaking anything.

By the numbers

50%+

Composites content in new aircraft models

5.65%

CAGR of air transport fleet growth

4.4%

CAGR of MRO market growth

16.5%

Aircraft incidents caused by structural failure

TRL6

Demonstrator readiness level achieved

Consortium partners

Demo deliverables built

The business problem

What needed solving

Aircraft increasingly rely on composite materials bonded with adhesives, but hidden defects like kissing bonds — where surfaces touch without truly sticking — are nearly impossible to detect with current methods. Structural failure causes 16.5% of aircraft incidents, and with the MRO market growing at 4.4% CAGR, manufacturers and maintenance providers urgently need reliable, non-destructive ways to verify bond quality without destroying expensive parts.

The solution

What was built

The project built two physical demonstrators: a laser shock and guided wave NDT system for detecting hidden bond defects (TRL6), and a mechanical testing setup for validating bond strength. Both were tested on representative aerospace samples. Six deliverables total were completed across the 3-year project.

Audience

Who needs this

Aircraft OEMs and Tier-1 composite structure suppliersMRO providers servicing composite aircraft (Boeing 787, Airbus A350 class)Automotive manufacturers adopting bonded composite body structuresWind turbine blade manufacturers using adhesive bondingQuality assurance equipment suppliers for aerospace production lines

Business applications

Who can put this to work

Aerospace Manufacturing

enterprise

Target: Aircraft component manufacturers and OEM suppliers working with composite materials

If you are an aerospace manufacturer dealing with quality assurance of adhesively bonded composite assemblies — this project developed a TRL6 laser shock and guided wave inspection system that reliably detects kissing bonds and hidden structural defects. With structural failure accounting for 16.5% of aircraft incidents, having reliable bond inspection directly reduces your liability and rework costs.

MRO (Maintenance, Repair & Overhaul)

mid-size

Target: Aircraft MRO service providers inspecting composite structures during maintenance

If you are an MRO provider struggling to inspect bonded composite repairs without disassembling entire sections — this project created non-destructive testing methods that detect defects in bonded assemblies inline. With the MRO market growing at 4.4% CAGR, having faster and more reliable inspection tools means shorter turnaround times and higher throughput for your facility.

Automotive & Advanced Materials

any

Target: Manufacturers using adhesively bonded lightweight composites in vehicles or structures

If you are a manufacturer adopting composite bonding for lightweight vehicle structures but lack confidence in bond quality — this project demonstrated mechanical testing and comparative NDT techniques for hybrid bonded assemblies. The inspection methods developed here can be adapted beyond aerospace to any industry bonding composites, helping you catch invisible defects before products leave the factory floor.

Frequently asked

Quick answers

What would it cost to implement this inspection technology?

The project does not disclose specific pricing or licensing costs. The system is built around laser shock equipment and guided wave sensors, which are specialized but commercially available components. Contact the coordinator (GMI AERO) through SciTransfer to discuss pricing for your application.

Can this work at industrial production scale?

The project explicitly targeted inline process inspection during manufacturing, meaning it was designed for production-line integration. The TRL6 demonstrator was tested on representative use cases and samples provided by the aerospace topic manager, confirming it works beyond the lab. Scaling to full production lines would require integration engineering but the core technology is ready.

What is the IP situation and can I license this?

The technology was developed under the Clean Sky 2 joint undertaking (CS2-IA funding scheme), which has specific IP rules favoring industrial exploitation by consortium partners. GMI AERO (France, SME) coordinated the project. Licensing arrangements would need to be discussed directly with the consortium through SciTransfer.

How accurate is the defect detection?

The project objective states the system achieves a high level of accuracy in detecting kissing bonds and structural defects in bonded assemblies. The guided waves demonstrator and mechanical testing demonstrator were validated against samples from the topic manager. Specific detection rates are not published in the available data but can be requested from the consortium.

What types of defects can this system find?

The system targets kissing bonds — invisible weak bonds where surfaces appear joined but have no real adhesion — along with other hard-to-find structural defects in adhesively bonded hybrid assemblies. It combines multiple NDT methods (laser shock, ultrasonic guided waves) and mechanical testing for comprehensive defect identification.

How long until this could be deployed in my facility?

The project reached TRL6 (system demonstrated in relevant environment) by its end in March 2022. Moving to full deployment would require TRL7-9 qualification steps specific to your application and regulatory environment. Based on available project data, the core technology is proven and integration timelines depend on your specific use case.

Consortium

Who built it

The consortium is lean and industry-focused: 3 partners across France and the UK with a 67% industry ratio. GMI AERO, a French SME specializing in aerospace composites and component manufacturing, leads the project and brings real production-floor experience. TWI (UK) is a world-renowned welding and joining technology institute contributing NDT and mechanical testing expertise. The university partner (BUL) handles laser shock and algorithm development. This is not a research-heavy academic consortium — it is built to deliver a working industrial inspection tool, which is exactly what a business partner wants to see.

GMI AEROCoordinator · FR
BRUNEL UNIVERSITY LONDONparticipant · UK
TWI LIMITEDparticipant · UK

How to reach the team

GMI AERO (France) — aerospace composites SME. SciTransfer can facilitate a direct introduction to the project coordinator.

Order a report on this consortium See GMI AERO profile →

Next steps

Talk to the team behind this work.

Want to explore licensing or integration of this NDT technology for your composite inspection needs? SciTransfer connects you directly with the research team — contact us for a one-page technology brief and introduction.

Order a report on this topic More in Transport & Mobility