Vertiflite May/June 2021

Airbus Starts Racer Assembly O n April 14, Airbus Helicopters announced that it begun assembly of its Racer high-speed demonstrator with the arrival of the center fuselage. Developed under the European Research Clean Sky 2 project, which involves 40 partners in 13 European countries, the Racer is designed for a cruise speed of 215 kt (400 km/h) and aims at achieving the best trade-off between speed, cost-efficiency and mission performance (see “RACER Takes Shape,” Vertiflite , July/ Aug 2020). It uses an innovative Safran eco-mode hybrid-electrical system, which allows one of the two Aneto-1X engines to be shut down while in cruise flight, reducing fuel burn. The aircraft was also designed for a lower operational acoustic footprint. The recent completion of the demonstrator’s center fuselage represents an important milestone for the program as it marks the start of the Racer’s assembly, taking place at Airbus Helicopters’ site in Donauwörth, Germany. Assembly involves By VFS Staff

Made of carbon fiber reinforced plastic (CFRP), the 11.1-by-4.9-ft (3.4-by-1.5-m) cover for the Racer’s side panels connects the tail boom to the aircraft’s cockpit. Such large-format CFRP shells are traditionally made manually, but the Racer’s shell components were manufactured in a highly automated process based on a new method developed by a research team from the Fraunhofer Institute for Foundry, Composite and Processing Technology IGCV in Germany. Developed by the German FastCan consortium, formed by KLK Motorsport GMBH and Modell und Formenbau Blasius Gerg GmbH, leveraged automotive design expertise andmanufacturing technologies to create a lightweight canopy that is optimized for low draft and a good field of view. The Racer canopy will integrate lightweight, erosion-resistant windows and windshields capable of withstanding bird strikes, even at very high speeds; the windshields were developed by the WIMPER consortium, which comprises the KRD Sicherheitstechnik GmbH, the German Aerospace Center (DLR), the Institute of Structures and Design, and Stuttgart University’s Institute of Aircraft Design. The British ASTRAL consortium, composed of AERNOVA Hamble Aerostructures and the Institute for Advanced Manufacturing at the University of Nottingham, are responsible for the design and manufacturing of the innovative Racer wings. Optimized for aerodynamic efficiency, the patented “double wing” or “box wing” provides lift in cruise mode while enhancing safety around the

demonstrator during ground operations. The wings have been designed with high- performance, environmentally friendly materials that reduce the weight of the aircraft. The wings enhance the helicopter’s performance by providing additional vertical lift and the ability to fly further and faster than traditional helicopters. Based on an Airbus Helicopters patent, the Racer rear fuselage was designed by the Airbus Helicopters teams in Spain, supported by the Aernnova- led Outcome consortium. Its dimensions, weight target and

asymmetric cross-section profile were a challenge, but the design was optimized for hover performance without penalizing forward flight. Finally, the Racer’s H-shaped empennage and double-canted vertical/horizontal stabilizer, patented by Airbus Helicopters and ONERA and devised to enhance stability and energy consumption, have also required the implementation of innovative technologies. The Racer will be the first Airbus aircraft to fly with a primary structure produced using additive manufacturing. Airbus unveiled the Racer at the Paris Air Show in 2017, it passed its critical design review in 2019 and manufacturing of long lead items began in 2020. Clean Sky 2 is also supporting the development of the Next Generation Civil Tiltrotor (NextGenCTR) with Leonardo Helicopters.

the installation of major components such as the canopy, box- wings, fuel system, cowlings, etc. Later this year, the Racer will be transferred to Airbus Helicopters’ site in Marignane, France, for the final assembly and subsequent launch of the flight campaign in 2022. The center fuselage section was designed and manufactured by Romania’s RoRCraft consortium, formed by INCAS (the National Institute for Aerospace Research “Elia Cafaroli”) and the aerospace company ROMAERO. The Racer lightweight airframe is a major achievement for the teams. This is the first time such an advanced hybrid helicopter structure, incorporating both metallic and composite primary structural elements, has been produced in Romania. The RoRCraft consortium will also be contributing to the demonstrator flight clearance by designing and conducting ground tests and stress analysis of the required fuselage parts.

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