User testing in VR: DLR's approach to cabin concept validation at 1:1 scale

Tools used

The problem with designing aircraft cabins from a sketch alone

"A sketch, a render, or a mockup can communicate an idea, but it does not always communicate the intended experience of being in that space. If these differences in interpretation are not discovered early, they may only surface later when changes are slower, more expensive, and much less welcome."

Sebastian Cornelje, Researcher and Designer, the German Aerospace Center (DLR)

Sebastian Cornelje is a researcher and designer at the German Aerospace Center (DLR), based in Hamburg, Germany. He works within a small design team inside a largely engineering-driven research environment, and they focus especially on the cabin design of aircrafts.

The team’s goal was to involve stakeholders earlier in the design process. Cabin crew, passengers, engineers, and designers all look at the same aircraft cabin and see something different based on their perspectives and needs. This has driven DLR to design the cabins from user out to ensure aircrafts are not only fit technically but also work for the people who use it.

To support this process, Sebastian’s team uses XR+ workflow that involves physical, hands-on ideation combined with full-scale immersive validation in Gravity Sketch. The “plus” stands for the extended reality layer added on top of traditional co-design methods, turning early workshop ideas into spatial concepts that every stakeholder can walk through, question, and refine together.

DLR’s XR+ workflow: from tabletop model to full-scale VR

Most cabin design processes begin with a “shot in the dark” where designers gather requirements from interviews and meetings and then translate them into an initial concept based on their own interpretation. This approach is often necessary, but it also buries a lot of hidden assumptions that only surface once stakeholders react to the first design. This can trigger many rounds of costly back-and-forth.

DLR wanted to move that friction earlier and added an “empathize” as the first step of the design process. Instead of only asking stakeholders what they need and defining the concept that way, the team lets them build and discuss the space together, first with simple arts and crafts materials, then at 1:1 scale in VR.

Step 1: Sensitization. Before any designing takes place, participants reflect on their own past experiences of the space in question: what worked and what didn’t. This primes them with concrete ideas to bring into the next step.
Step 2: 1:20 ideation. Using simple scale blocks, typically 1:20, participants explore different variations and physically lay out their ideal version of the space. The constraints are low and the building material is tactile.
Step 3: Translation. The tabletop model is rebuilt in Gravity Sketch using matching low-poly blocks. Details are still minimal so that the focus stays on function and layout rather than aesthetics.
Step 4: 1:1 immersion. The model is scaled up to 1:1 and participants step inside it in VR. This is where new insights often appear: sightlines, reach, and movement that looked fine on the tabletop often don’t hold up once experienced at true scale, and participants start reshaping the design on the spot.
Step 5: Reflection. The group discusses what worked and what to improve, both around the design itself and about the method. This closes the loop for the next session.

VR user testing in action: 3 example projects using DLR’s XR+ workflow

1. The Flying V galley

DLR ran five workshops with KLM cabin crew to design the galley, the aircraft’s onboard kitchen and crew workspace, for the Flying V, a flying-wing concept aircraft with no conventional cylindrical cabin to fall back on. At the tabletop, the crew used 1:20 scale miniature models and converged on a bar-shaped galley in the center of the cabin.

Once immersed at 1:1 scale in Gravity Sketch, the crew found that the sightlines didn’t work well. That triggered a redesign into a V-shaped galley with eye-level food and drink access, dedicated workspace, hidden trolley storage, and an added rear exit for faster crew movement. All of these details only emerged once the crew could stand inside the space they’d sketched.

2. A rescue helicopter cabin

To test whether the same workflow can be applied in a smaller, life-critical environment, DLR used it to design a rescue helicopter cabin. Paramedics and physicians first worked on a simplified 1:20 cabin shell before the model was rebuilt in Gravity Sketch for true-scale review.

Inside VR, the group added a second pair of stretchers, a criticality-based layout placing the most seriously injured patients within easiest reach, and a 360-degree rotating seat. When DLR later imported the full engineering model, including the rotor gearbox, they discovered the four-stretcher layout wasn’t physically achievable and had to scale back to two.

The lesson cut both ways: bringing real engineering data in early exposes genuine spatial constraints sooner, while working from a simplified shell earlier in the process gave paramedics room to imagine solutions unconstrained by engineering limitations.

3. A hydrogen aircraft “third space”

For a more exploratory project, DLR invited 65 passengers with no prior XR experience into 18 two-hour sessions to design a “third space” for a conceptual hydrogen aircraft. A third space refers to a space that is neither home nor work, like a park or a cafe. In aircraft context, it would be a space away from the aircraft seating area.

After a short introduction that covered how to use grab, duplicate, and undo buttons, participants who had never used Gravity Sketch before produced concepts ranging from a self-service catering bar and family lounge to a stretching and relaxation area and a kids’ corner.

Lessons DLR learned from testing aircraft cabin designs in VR

The XR+ workflow, using Gravity Sketch, has helped Sebastian’s team achieve more efficient design process:

Earlier spatial awareness at 1:1 scale
new ideas emerge inside the model
Tacit user knowledge becomes visible
From separate to one shared interpretation
Turns user experience into usable spatial design input

The workflow surfaces things a sketch or floor plan can’t, including scale, reachability, movement, and whether a layout genuinely feels workable. Immersion also turns out not to be just a validation step. Participants keep generating new ideas once they’re inside the space and they notice things they hadn’t considered until they’re standing in them.

Tacit, experience-based knowledge, like where cabin crew instinctively want to stand or what needs to be within arm’s reach, becomes visible in a way it rarely does in conversation alone. And because every stakeholder discusses the same 1:1 model rather than their own mental image of a sketch, the workflow closes the interpretation gap that normally drives rounds of rework later in the process.

"Gravity Sketch became more than a modeling tool. It became a shared thinking space where all these stakeholders, users, designers, experts, cabin crew, rescue helicopter workers, all came together, could understand, question, and improve the same spatial idea together. And that's really the goal: it's not just creating a model, but it’s really creating alignment. And alignment isn't just a soft benefit. A team that agrees from a very early stage on the same spatial reality later produces fewer surprises, fewer change requests, and less rework once a design moves towards engineering and production."

Sebastian Cornelje, Researcher and Designer, the German Aerospace Center (DLR)