New Technologies Make Helicopters Quieter, More Efficient, and Faster…

BELL TEXTRON

Bell Textron, Inc. is currently seeing with the Bell 505 that investments in new technologies lead to success on the market: The manufacturer has delivered more than 360 of the newly developed single-engine light turbine helicopter in just a few years. New systems that make flying safer, easier, and cheaper are arguments for many customers to justify switching from an older helicopter model to a new one. 

Bell is currently researching an electrically powered tail-rotor system for helicopters in collaboration with France’s Safran Group. A proof-of-concept system has been flying on a Bell 429 in Canada since May 2019. The patented Electrically Distributed Anti-Torque (EDAT) system consists of four shrouded rotors, each driven by its own electric motor. Each rotor has four blades that are non-adjustable. The new system is controlled via fly-by-wire. The electric motors respond extremely quickly and provide the thrust needed at any given time by constantly changing speeds. 

Bell believes EDAT is quieter, lighter, more reliable, and safer than conventional tail-rotors because it does not require a shaft or gearbox. The Bell 429 EDAT is purely a proof-of-concept aircraft. Only after completion of the tests will the manufacturer decide whether and in what form the new tail-rotor system can find its way into production helicopters. 

LEONARDO

Italian manufacturer Leonardo is also working on several innovative projects and is thus actively shaping the future of VTOL aviation. The manufacturer has been developing the AW609 civil tiltrotor aircraft since the mid-1990s. Initially with Bell as a programme partner, and since 2012 on its own. Thanks to its forward-tilting rotors, the AW609 combines the advantages of a helicopter with the cruise speed of a turboprop aircraft. Leonardo expects to certify the AW609 in the near future. At Heli-Expo in March, in Dallas, Texas, the manufacturer signed a contract with an unnamed European customer for the sale of four AW609s. The customer plans to use the aircraft for VIP transport and utility flights on various missions, according to Leonardo. 

In the light helicopter sector, Leonardo has acquired Swiss manufacturer Kopter. The company is expected to drive innovation in this market segment in the future as a centre of excellence for light helicopters. Leonardo sees its Swiss subsidiary as an incubator for new technologies for vertical take-off and landing aircraft. In this context, the development of new hybrid and electric propulsion systems plays an important role as part of Leonardo’s strategic business plan, ‘Be Tomorrow 2030’.

AIRBUS HELICOPTERS

Airbus Helicopters' RACER (Rapid And Cost-Effective Rotorcraft) technology project aims to make helicopters more efficient, quieter and, above all, faster. RACER is designed for a cruising speed of 400 km/h (216 knots) and is being developed as part of the European Clean Sky 2 research programme. A total of 40 partners from 13 nations are working on RACER, including research organisations such as France's ONERA and Germany's DLR. 

RACER is scheduled to fly in the fourth quarter of this year. The prototype of the high-speed helicopter is currently undergoing final assembly at Airbus Helicopters in Marignane, France. In addition to a main rotor, two five-blade propellers from MT-Propeller mounted laterally on box-wings provide the necessary propulsion. The booms are made of carbon fibre composites and profiled, as they also provide lift during forward flight. 

The tailboom has a special feature in that it is not symmetrical in cross-section. The right-hand side of the tailboom in the direction of flight was designed with a cantilever, while the left-hand side slopes almost straight down. This offers aerodynamic advantages, because the tailboom thus acts like an aerofoil and makes optimum use of the downwash of the main rotor. In hover, this is expected to improve the helicopter’s performance by up to ten percent, according to the manufacturer. 

Although the RACER is purely a technology demonstrator that will not go into series production in this form, the high-speed helicopter was designed to be as practical as possible. For example, despite the lateral propellers, safe winch operation should also be possible. 

The RACER project is not only about new speed ranges for helicopters but is, above all, about technologies that reduce helicopter fuel consumption. For example, the Eco-Mode system from engine manufacturer Safran Helicopter Engines aims to minimise fuel consumption by shutting down one of the two Aneto 1X engines during cruise flight. In addition, RACER is intended to be a particularly quiet and low-vibration aircraft despite its top performance. 

The technical possibilities for improving helicopters are far from exhausted. Even if in the future eVTOL aircraft take over tasks that today can only be performed by helicopters, the latter are nevertheless irreplaceable in many areas of operation.