1. Can you tell us a bit about your role within the COCOLIH₂T project and what Work Package 8 focuses on?

Within COCOLIH₂T I lead Work Package 8, on Safety & Lifecycle Evaluation. In this work package we had two aims: One, to understand the potential safety risks of a liquid hydrogen tank and how these could be mitigated in the tank design, and two, to understand the durability and lifecycle impacts of the tank. In particular, in  COCOLIH₂T we chose for a carbon fibre / thermoplastic tank made with automated fibre placement, and we wanted to understand how this compared in terms of environmental impact to a more traditional carbom fibre / epoxy concept.

2. What has been one of the most interesting or unexpected challenges so far, and how did you and/or your team approach it?

There are of course no commercial flights operating on liquid hydrogen yet, so we had to perform a safety assessment on a new design, without having historical data to help us quantify the risks. To get around this, we analysed historical data from other sectors, where there is more experience with using hydrogen. From these we estimated both the frequency and the potential impact of different safety hazards.

3. What are some key lessons or takeaways you’ve gained from working on COCOLIH₂T?

A key lesson was that it was still possible to conduct a quantitative preliminary safety assessment, even on a new technology like a liquid hydrogen tank for aviation. We also saw that in manufacturing, a lot of the environmental impact comes from the mould materials, especially if there are low production volumes. Ensuring that hydrogen permeation / leakage is avoided also requires careful lay-up design to keep the transverse stresses in each ply low enough. Doing this on a design is one thing, but then ensuring the analysed lay-up also is manufacturable adds an additional challenge.

4. Looking ahead, how do you think this project could shape future research or industry practices?

Hopefully our preliminary safety analysis can guide further design and development of aviation liquid hydrogen tanks.

We also saw that conducting a thorough fatigue and durability analysis on a liquid hydrogen tank will require extensive material characterisation work under cryogenic conditions. Here a lot of research effort is still needed.

5. If you could describe the COCOLIH₂T project in three words, what would they be — and why?

Challenging – We faced many challenges, particularly in manufacturing such an unusual shape and dealing with the limited amount of available data.

Persistence – Despite setbacks we always found a way to keep moving forward

Creativity –  COCOLIH₂T really moved into new areas in different ways, requiring a lot of exploration and creativity to figure out how to design and manufacture our tank.

1. Can you tell us a bit about your role within the COCOLIH₂T project and what Work Package 4 and 5 focus on?

Jorge – Within COCOLIH₂T I am both a work package and task manager. Therefore I must coordinate the work of the different consortium partners within work package 5. In work package 5 we are developing the different subsystems which allow for the filling and emptying of the tank, as well as it’s monitoring. Within my task I am developing the controller subsystem, which controls and manages the (de)fuelling process and coalesces all sensor inputs to allow for effective and safe operations.

Arne – Like Jorge, I’m operating as a work package manager in COCOLIH₂T, focusing on thermal and pressure management. Since LH₂ tank design is a multi-faced challenge, interaction between the thermal team and mechanical team has been a crucial part of the developments.

2. What has been one of the most interesting or unexpected challenges so far, and how did you and/or your team approach it?

Jorge – The most challenging development for us has been dealing with our subsystems’ operations in the cryogenic environment, both from functionality and safety standpoints. To fulfill this we have followed courses from experts in order to ensure compliance with regulations for Equipment for potentially explosive atmospheres (ATEX).

Arne – For the thermal part, the introduction of metal interfaces to the composite tank has been most challenging and rewarding. Additionally the “thermal bridging” and leak tightness has been a challenge, which matched well with our teams’ background expertise in space thermal management for equipment on board of ISS.

3. What are some key lessons or takeaways you’ve gained from working on COCOLIH₂T?

Jorge – That the safety of our operators is paramount and no shortcuts will be taken there. With experimental technology this sometimes requires a pragmatic approach, where rather than full certification of integrated equipment, detailed analyses are conducted to assure safe operations.

Arne – Couldn’t agree more with Jorge here. Although challenging at some times, the pragmatic approaches here have been a key driver of success in the program.

4. Looking ahead, how do you think this project could shape future research or industry practices?

Jorge – While most of the project’s outcomes relate to composite design, at NLR we have also learned a lot relating to optical and low-thermal-conducting sensing technologies. Thanks to our work in COCOLIH₂T, we have successfully advanced the TRL of these technologies such that they can be implemented in cryogenic environments outside the lab, further positioning the EU for zero-emission aviation.

Arne – There’s many improvements to be made still, but I’m glad that with COCOLIH₂T we have been and remain at the forefront of entry into service of H₂-aircraft.

5. If you could describe the COCOLIH₂T project in three words, what would they be — and why?

Innovative – since we are working with new technologies which have not been commercialised yet, but will become part of the future of clean aviation technology

Flexible – due to the complexities involved with the manufacturing of the composite tank, we have had to remain flexible in development and testing

Forward-thinking – (does a hyphen count?!) We are developing technology for the future of aviation, not immediately applicable. Our teams’ capabilities to look beyond current applications has helped us in reaching the next step.

This week the COCOLIH2T team was excited to welcome the first of two technology demonstrators, successfully delivered to NLR by Novotech (Italy).

With final testing planned for January 2026, the team focused on test preparations and completed a multi-day workshop capturing lessons learned from Demo 1. The week included:
A deep dive into Automated Fibre Placement for thermoplastic composites
An executive board working session
A full programme general assembly

Looking ahead, COCOLIH2T is preparing for the Critical Design Review (CDR) of Demo 2 and the Test Readiness Review (TRR) of Demo 1 in early 2026.
Great teamwork, productive discussions, and strong collaboration across all partners. On to the next milestones!

Can you tell us a bit about your role within the COCOLIH₂T project and what Work Package 2 focuses on?

Unified International’s main contribution to COCOLIH₂T has been in Work Package 2, where we provide an end-user perspective. In the Netherlands, through our subsidiary Conscious Aerospace, we are developing a hydrogen powertrain and storage system that can be retrofitted into regional aircraft. This means we could be a potential end-user of the COCOLIH₂T tank system, and we can directly apply the lessons learned from this project.

Within WP2, our work has centered on defining requirements from an end-user standpoint and supporting interface definition and the requirements from fuel cell system. Together with ATR, we have also contributed end-user input to other work packages throughout the course of COCOLIH₂T.

What has been one of the most interesting or unexpected challenges so far, and how did you and/or your team approached it?

For Unified, the conformal shape is promising and important as it optimises the tank space envelope in the fuselage, leaving more room for payload. This is also one of the most interesting challenges in COCOLIH2T in general: designing a conformal composite tank that meets aviation standards. It required balancing technical innovation with strict safety and certification demands. The COCOLIH2T team approached this by working closely with consortium partners, openly sharing expertise, and iterating on designs until we found practical, feasible solutions.

What are some key lessons or takeaways you’ve gained from working on COCOLIH2T?

A key takeaway is the unique set of design and manufacturing challenges that come with creating a conformal tank. Developing a fully composite conformal structure is far from straightforward, and we gained valuable insights into the difficulties of manufacturing such shapes. For our technology roadmap at Unified / Conscious, we would need to assess the benefits against the drawback and risks to assess when conformal tanks become an (economically and technically) viable solution .

Another important lesson has been the selection and integration of appropriate gauging systems for hydrogen applications in aviation, which also applies to more traditional tank shapes and materials. Both of these areas will continue to shape our work moving forward.

Looking ahead, how do you think this project could shape future research or industry practices?

COCOLIH₂T provides deep insight into both the practical challenges and the potential advantages of building an aviation-ready conformal composite hydrogen tank. The technical lessons learned here lay the foundation for continued development in follow-up projects.

For us, the findings are directly relevant to our national hydrogen aviation program, led by Conscious Aerospace, and will inform our future steps.

 If you could describe the COCOLIH₂T project in three words, what would they be — and why?

Collaborative, ambitious, practical.

• Collaborative, because the cooperation within the consortium has been excellent and highly constructive.
• Ambitious, because of the ambitious scope, planning, and project goals, which are extremely relevant to hydrogen powered aircraft.
• Practical, because the solutions found together are hands-on, results-oriented, and grounded in real-world application.

Karthik Ramaswamy, Ph.D. (Collins Aerospace Ireland) and Paul Liddel (Crompton Technology Group) recently had the opportunity to visit Novotech’s manufacturing sites in Avetrana and Casoria (Italy) as part of the EU-funded COCOLIH2T project – aimed at pushing the boundaries of sustainable aviation through a novel conformal composite LH₂ tank concept.
In Avetrana, we explored their Automated Fibre Placement (AFP) facility, where the inner LH₂ tank is being manufactured. In Casoria, we visited the facility where the outer tank is being manufactured — a critical factor in the success of this conformal tank design.

🤝 It was a pleasure engaging with the entire Novotech team — all passionate engineers tackling tough challenges with energy and ingenuity.
🌋 And of course, no trip to Italy is complete without a few memorable moments — the view of Mount Vesuvius from our meeting room, and the unbeatable pizza at L’Antica Pizzeria da Michele, possibly the world’s oldest pizzeria.
Grateful for the insights, the collaboration, and the warm hospitality. Looking forward to the exciting milestones ahead in this ambitious project.

The team in NOVO's premises in Avetrana (Italy)

In recent weeks, liquid hydrogen tests were conducted at NLR in Marknesse. This marks a continuation of LH2-testing, following up on the kick-off of LH2 tests back in December 2024. Part of the testing took place at NLR’s new test location for H2 tests: the EPTF – Energy to Propulsion Test Facility.

As part of the Clean Hydrogen COCOLIH2T program, a Collins Aerospace’s LH2 level sensor prototype was validated and calibrated in NLR’s LiHCA – Liquid Hydrogen Cryostat test Apparatus. This setup provides an LH2 bath for all types of sensor calibration. For calibration of the LH2 level sensor, NLR provided the validation methodology using differential pressure sensors. The performed tests were successful, and much was learned in preparation for the full-scale testing ahead. Thanks to all involved for the collaboration.

NLR and Collins teams, with LiHCA test apparatus