In 2022, Shanghai’s TCab Tech is steadily pushing forward its E20 electric vertical takeoff and landing (eVTOL) development. During the first quarter of the year, the Chinese startup successfully completed dozens of tilt-rotor transition flights with a 50%-scale demonstrator of its planned E20 eVTOL air taxi.
The demonstrator serves as a flight-testing platform for the engineering team to collect valuable flight test data for early validation of the E20 configuration and design. The company previously flew a 25%-scale demonstrator of the vehicle in August, which had completed hundreds of transition tests by October.
The E20 50% subscale demonstrator features a 19.7-ft (6-meter) wingspan, two lift rotors, and four tilt rotors. Like the E20, the demonstrator uses six rotors in VTOL and transits to four rotors in the cruise. The two lift rotors are switched-off and locked during cruising flights. TCab Tech claims the E20 will only go as fast as 260 km/h (162 mph) and promises some 200 km (124 miles) of range.
The company says it’s completed dozens of flight tests taking this 50% scale prototype through the tricky process of transitioning to winged cruise flight and back again. Compared to the previous 25% subscale demonstrator, the 50% version of the E20 is larger in size and has exactly the same external layout as the full-scale E20. The external layout included flaps and variable pitch rotors to improve control laws and aerodynamics validations. The flight data collected using many data-feedback sensors could be used to further improve aircraft control algorithms.
The E20 50% subscale demonstrator completed its maiden flight in December 2021. After several months of continuous and high-density running-in and test flight, the team has established a complete test flight, including route planning, logistical maintenance, inspection and release, and safety assurance. It also has a deeper understanding of the aerodynamic performance and tilting characteristics of the aircraft, which provides strong support for the ongoing development of the E20 eVTOL prototype.
While serving as a flight-testing platform, the E20 eVTOL 50% subscale demonstrator is also used to develop in-house structural and durability test facilities, electric motor test rigs, and SIL and HIL flight simulation labs. The know-how gained from the flight testing and the facilities built will pave a smoother path for the company to prepare for getting airworthiness certification from the Chinese airworthiness authority.