“The project resulted in an increased understanding of noise and its propagation on the ground from drones, which will be used to plan drone flights in a way that enables more drone transport with minimal people being disturbed by its noise. This in turn leads to more energy-efficient transport with maintained or increased quality of life”, says Erik Wiberg, Co-founder & CEO Katla Aero.
Challenges
Katla Aero is developing Katla3, the vertical take-off and landing (VTOL) logistics and Unmanned Aerial System (UAS). A fixed-wing aircraft equipped with ten lift rotors for vertical take-off and landing and two propellers for cruise flight. While this design offers operational flexibility, noise emissions during different flight phases pose a significant challenge for regulatory compliance and community acceptance.
New European Union Aviation Safety Agency (EASA) and Federal Aviation Administration (FAA) guidelines require manufacturers to quantify and manage noise impacts, and certification standards are evolving rapidly. Katla Aero needed accurate noise characterization and predictive tools to ensure its aircraft could meet future requirements and operate in sensitive environments without compromising public trust.
Solutions
Aero EDIH supported Katla Aero through noise measurement and modelling. Field tests were conducted using EASA-style procedures, including flyover measurements at 60 meters above ground level (AGL) and hover tests at 17.5 meters AGL. Class-1 instruments were calibrated before and after tests to ensure accuracy.
The data was processed to derive A-weighted sound power levels (LwA) and analyzed for tonal components such as blade-passing frequency. Advanced simulation tools (SAFTu) were then used to create ray-traced noise maps for representative logistics routes, integrating population data from SCB (Statistiska Central Byrån) collecting statistics in Sweden, to visualize community exposure.
Results and Benefits
The study provided Katla Aero with robust source models for its aircraft in both hover and cruise modes, enabling accurate prediction of noise footprints. Simulations revealed that vertical-lift phases dominate local audibility, while cruise segments produce short-duration, relatively modest acoustic events that blend into the background. By visualizing these dynamics through noise maps, Katla Aero can now engage stakeholders with clear evidence and plan operations that minimize community impact.
Operationally, the findings highlight the importance of optimizing transition from hover to wing-borne flight as early as possible. Procedures that reduce time spent in vertical-lift mode significantly shrink noise exposure zones around launch sites. These insights will inform standard operating procedures and training, ensuring predictable and acceptable outcomes.
From a regulatory perspective, the project establishes a repeatable methodology for noise assessment, positioning Katla Aero to align with emerging certification frameworks and strengthen its market competitiveness.
Perceived Social Economic Impact
By addressing noise proactively, Katla Aero contributes to the sustainable integration of drone logistics into regional mobility systems. The ability to demonstrate compliance and manage community exposure supports public acceptance, accelerates regulatory approval, and fosters economic growth through innovative logistics solutions.
Lessons Learned
Engage in early noise testing under standardized conditions to build credible source models. Use simulation and mapping tools to translate technical data into actionable insights for route planning and stakeholder communication. Integrate noise-aware procedures into operational planning and crew training.
Do not underestimate the impact of hover and transition phases. Lingering in vertical-lift mode near populated areas expands noise footprints dramatically. Avoid shallow climb profiles or extended mixed-mode segments, as these increase exposure and community sensitivity.
“Aero EDIH has during 2025 supported Katla Aero AB in a project performing noise measurements of drones, executed by Akustikdoktorn AB. Noise performance is becoming a decisive factor for the commercial and societal acceptance of drones and eVTOL systems, and a core enabler in the EU Drone Strategy 2.0. As new measurement and certification standards emerge from EASA and the FAA, manufacturers must be able to demonstrate not only compliance, but also a clear methodology for noise minimisation across all flight modes.
By combining field measurements with advanced acoustic modelling of lift, hover, transition, cruise, and descent, we are establishing representative source models that translate physics-based understanding into practical design and planning tools. This capability enables manufacturers to produce credible noise maps for real operational scenarios, support customers in impact assessments, and proactively adapt to forthcoming regulatory requirements.
Ultimately, systematic acoustic measurement and modelling are not just about compliance – they are a competitive advantage. They provide Swedish UAS manufacturers with a concrete foundation for quieter designs, smoother certification pathways, and sustainable deployment of drone-based services in urban and regional airspace”, says Rasmus Lundqvist, Innovation lead, Aero EDIH.
