High-speed rotary aircraft technology

Participation in the advanced rotary aircraft technology wind tunnel testing campaign in DNW

JAXA conducted an active twist wind tunnel test in the German-Dutch Wind Tunnels (DNW) large low-speed facility (LLF) in Marknesse, the Netherlands, in October 2025 in collaboration with the German Aerospace Center (DLR), DNW, the French Aerospace Lab (ONERA), the National Aeronautics and Space Administration (NASA), the United States Army (U.S. Army), the Korea Aerospace Research Institute (KARI), and the Konkuk University.

Active twist is a technology that actively twists helicopter blades. This technology has the potential to control helicopters without conventional swashplates, in addition to reducing helicopter vibration and noise. An active twist can be applied to a high-speed compound helicopter JAXA has been studying, as well as to a conventional helicopter.

In this wind tunnel test, a DLR-manufactured 4-meter-diameter rotor blade was used. The objective of the wind tunnel test was to validate vibration and noise reduction effects by active twist. Airloads, elastic deformations, and blade vortex interaction (BVI) noise of the rotor blades were measured in an airflow in DNW-LLF. JAXA made a contribution to the selection of the test cases through preliminary analyses of blade airloads and elastic deformations.

Predicting blade elastic deformations in high-speed flight is one of the most important technologies in high-speed rotorcraft study at JAXA. In this wind tunnel test, the accuracy of the predicting software developed by each organization was validated through cross-comparison of their respective results. The blade elastic deformations will be predicted using the validated software. JAXA will continue making contributions to the realization of a high-speed rotorcraft.

February 17, 2026