The mould of the fuselage of the world’s first liquid hydrogen-powered aeroplane? We’re talking students here, so naturally it has been propped up with empty beer crates. And the students don’t use expensive ovens to proof their glue, but polystyrene igloos in the toilet block. The red brick hall near the Rotterdam airport of Zestienhoven is rather chilly. “Which is why we set up that igloo in the toilet block: that’s where the boiler for the central heating is, so the temperature’s slighter higher there than in the other areas,” says a smiling Sam Rutten (22), who studies Project Management at Delft University of Technology.
Rutten is working together with EUR student Olivier van Haren (24) and 44 other students on what’s intended to become the first aeroplane powered by liquid hydrogen. They are both on the AeroDelft management team. Van Haren, who’s doing a master’s in Accounting & Auditing at Erasmus School of Economics, is the first EUR student to become involved in this project – in the capacity of financial manager. He holds the purse strings, in other words. Their budget? “Close to one million.”

The AeroDelft team are working hard on the first prototype for the aeroplane: the ‘Phoenix PT’. Some guys are walking around wearing gas masks, while others are experimenting with spark generators (sounds like a taser) on different parts of the plane to see whether they block sparks effectively. “If any of those comes in contact with hydrogen, the whole thing will blow sky high,” says Van Haren. He knows how it works but refers to his colleague anyway, just to be sure. “Right, Sam?” he asks. Or: “I have to check with my colleague here, to see whether I’ve explained it correctly.” It turns out he’s right. “Hydrogen comes in two forms, gaseous and liquid. We’re building the first aeroplane to be powered by liquid hydrogen.”
250 degrees below zero
Rutten tells us that this won’t be the first time an aircraft is powered by hydrogen as such. “Usually, you’re flying with a tank full of hydrogen in gas form. But gaseous hydrogen is voluminous. On top of this you need a very heavy tank for transport, which isn’t practical for aviation. When you convert this hydrogen to liquid, it takes up very little space – meaning you can install a far lighter weight tank.” The catch: “Hydrogen only enters its liquid phase at minus 250 degree Celsius. So you have to construct a system that can handle extremely low temperatures .”
And hydrogen can be rather dangerous too. Van Haren: “If you mix it with air, it may explode and set the entire building on fire. It can already make a big blaze with as little as 4% hydrogen to air.” But they can do this, says Rutten, with an assuredness that seems to make it the most natural thing in the world that this major breakthrough in sustainable aviation will be pulled off by students.

Rutten and Van Haren are currently working together on the prototype: a 1:3 scale drone version of the actual plane. Van Haren’s contribution is still mainly limited to practical jobs like sanding and carrying stuff. Rutten directs the team who are building the prototype and helps them with technical questions. Due to Covid, the two have spoken numerous times via video conferencing: this week of building is actually the first time they see each other face to face – taking due regard of the health precautions of course.
Instagram and AA battery
How does a student at EUR end up contributing to a technical project like this? “It was very ‘2020’, actually. I saw a call posted on Instagram. It’s a great project, and it could make a real difference in terms of sustainability. Flying is one of the most polluting activities you could think of, so it would be very cool if I could actually help solve this problem.”
Some of the technical details are over his head. But the important thing is that he can clearly explain the gist of the project to the outside world – during talks with ‘the partners’. “By now, I’ve accepted that I’ll never completely understand what they’re talking about when they go in-depth during meetings – I have to sit those discussions out.”
That could be hard in the beginning though. “Particularly because it was all online. Although they filled me in on loads of stuff, and I did a lot of reading up. I keep an eye on the budgets and monitor whether enough money is coming in via sponsoring and partners, and how we’re spending it. But if someone tells me, ‘I have to buy a new battery: it will cost us 15,000 euros,’ I have to take him at his word. As far as I know, he could be talking about an AA battery that you pick up at the Albert Heijn. So they also have a certain responsibility in that area.”
Finding investors can be a challenge, particularly in the midst of a pandemic. “We’re on schedule in financial terms, but it’s difficult to secure financing for aviation during the Covid crisis,” says Van Haren with a smile. “A lot of parties are interested in the project, but they mainly want to share their expertise. A law firm is helping us with the legal aspects – and we’re very happy with their support. But sourcing new funds is more challenging. We’re currently studying which grants we may be able to tap into.”

Law firm
When it comes to financials, Van Haren has proven a real asset to the team, says Rutten. “We have all sorts of different departments that need to be managed – meaning you don’t have time left to think about how we’re going to pay all these plans. Olivier consistently serves as a link between the technical teams and the teams responsible for raising funds. We used to rely on fellow students from Delft for this. That went well too, but you can see that Olivier has a really good command of this material – including VAT and stuff like that.”
The collaboration has given them a taste for more. “We have also recruited a human resources manager from Rotterdam School of Management. And we’ve sent out an e-mail to law students in Rotterdam regarding the various legal details associated with aviation.”
If things go according to plan, the plane will be making its maiden flight in 2025. They will be the very first team to get that far, expects Rutten. And get there they will, he doesn’t mind reiterating. They plan to fly the prototype as soon as this summer. Their secret? “We’ve got guts, no commercial interest, aren’t accountable to anyone – meaning we have a lot of freedom – work on a voluntary basis and watch every penny.” And that final point is also a feather in Van Haren’s cap.