Beyond Aero has successfully completed its first wind tunnel test campaign, a major milestone towards the end of the Preliminary Design phase of its hydrogen-electric aircraft. Conducted over five weeks in autumn 2025 at the German-Dutch Wind Tunnels (DNW) Low-Speed Facility (LST) in Marknesse, the campaign focused on one of the program’s most critical challenges: ensuring predictable aerodynamic performance, stability, and control for an aircraft integrating gaseous hydrogen tanks outside the fuselage.

Hydrogen propulsion introduces architectural constraints that fundamentally shape aircraft aerodynamics. For safety reasons, Beyond Aero’s design integrates gaseous hydrogen tanks externally, creating complex aerodynamic interaction zones at the wing-fuselage junction and wingtip — regions where even minor geometric effects can significantly influence lift, drag, and stability.

While numerical simulations provided initial confidence, these interactions could not be fully de-risked through computation alone. As has been the case since the earliest days of aviation — from Gustave Eiffel’s pioneering aerodynamic experiments on its tour, to today’s large-scale facilities — wind tunnel testing remains essential to validate new aircraft architectures under real flow conditions.

The objective of this first campaign was not only performance optimization, but also confirmation that the hydrogen-driven external configuration behaves in a stable, predictable, and controllable manner across the intended flight envelope.

From numerical models to experimental proof. The wind tunnels  tests were performed on a 1:8 scale model and generated more than 60,000 data points. The campaign investigated aircraft performance, stability, and control across a wide range of configurations including multiple flap settings, control surface deflections, and off-nominal conditions such as high angles of attack, sideslip, up to deep stall. Testing was conducted at speeds up to 80 m/s (288 km/h).

Measurements combined global aerodynamic forces and moments, captured via a six-component balance, with detailed local pressure data from more than 230 pressure taps distributed across the model. The resulting dataset enabled robust correlation with numerical simulations and provided high-fidelity experimental reference data for the aircraft’s external aerodynamics.

AI accelerated the development of tools to facilitate correlation and visualization across large experimental and numerical datasets, and to optimize conventional aerodynamic validation processes. These tools helped engineering teams identify trends, assess sensitivities, and converge more efficiently.

The results confirmed the robustness of Beyond Aero’s aerodynamic design choices. Beyond validating numerical models, the campaign confirmed the primary aerodynamic assumptions associated with the hydrogen architecture, enabled detailed characterization of critical interaction zones, and reduced residual aerodynamic uncertainty ahead of geometry freeze and subsequent development phases.

“The development of a hydrogen-electric aircraft requires precise aerodynamic design. The strong correlation between experimental results and numerical simulations,  in the linear domain, gives us a solid validation of our numerical process,” said Delphine Bonnaud, Head of Aerodynamics at Beyond Aero.

“This wind tunnel campaign delivered high-quality experimental data that directly supports our aerodynamic models and design decisions. It contributes to the validation of the aircraft’s Preliminary Design Review by providing a solid experimental reference for the external aerodynamics,” said Luiz Oliveira, Chief of Engineering at Beyond Aero.