Japanese eVTOL aircraft developer SkyDrive Inc. has successfully accelerated its SKYDRIVE aircraft, the SkyDrive Model SD-05, to a speed of 100km/h.
This achievement marks a viable speed for the commercialization of short hop inter-urban air mobility. Through a series of high-speed tests, the company verified the aircraft’s high-speed stability, controllability, and maneuverability, alongside the performance of its propulsion systems, flight control systems, and on-board avionic equipment.
The data gathered through the high-speed flight test campaign allows engineers to confirm the accuracy of the aircraft characteristics and dynamic behavior predicted through advanced design and analysis. This marks a major step toward type certification and the planned commercialization of the aircraft in 2028. However, the significance of achieving stable flight at 100km/h goes beyond simply reaching a certain number on the airspeed indicator.
Aircraft development begins with design and analysis, proceeds through individual system tests and ground tests, and then moves on to the manufacture of a full-scale aircraft and flight testing. At the same time, simulators are used to repeatedly verify flight characteristics, propulsion systems, and flight control systems. While simulation, analysis, and ground testing are all key parts of the process, the final flight testing stage is critical. There are some things that cannot be known until the aircraft actually flies. This is particularly true of high-speed flight, where aerodynamic forces, vibrations, structural loads, and flight control system response all change and interact in complex ways. Flight testing is the only way to verify whether the results predicted during the design phase accurately describe the aircraft’s in-flight behavior.
As the aircraft is based on a completely new concept, distinct from conventional fixed-wing aircraft and helicopters, existing knowledge and flight data cannot be assumed to apply. Every new aircraft needs to collect and verify data through actual flight tests, but with a new aircraft concept, this phase becomes even more indispensable. The successful achievement of 100km/h flight is the culmination of a long process. The capacity to conduct safe and stable high-speed flight is built on simulations, wind tunnel tests, ground tests, and various system tests, all of which are required to acquire know-how and data on the aircraft’s flight characteristics.
SkyDrive has conducted an extensive range of flight testing, with development experience dating back to its SD-03 prototype, accumulating hundreds of test flights since then. Outside of flight testing, the wide-ranging test program also includes standalone testing of batteries, motors, and rotors, aerodynamic performance testing in the wind tunnel at JAXA (the Japanese space agency), and ground vibration testing. Furthermore, step-by-step flight control tuning utilizes real-time data collected from low- and mid-speed flights, which engineers and pilots use to take cautious decisions at each stage of the flight test campaign on whether to proceed with faster, expanded flight profiles.
Around the world, many companies are developing eVTOL aircraft. The industry is currently moving beyond the phase of demonstrating that such aircraft can actually fly and into a more advanced phase of gathering the evidence required to show that the aircraft can operate stably at high speed, collecting the data required by regulatory authorities for certification, and demonstrating the viability of future commercial operations.
SkyDrive says it will continue with high-speed testing to expand the aircraft’s flight envelope at the speeds required for commercial operation, collect further data and know-how, and clarify that the flight performance of the aircraft continues to match the performance expectations predicted during the design and analysis phase. SkyDrive’s journey towards certification and the start of commercial operations in 2028 continues.
