Safran Helicopter Engines Advances Fuel-Saving Helicopter Eco-Mode

LE BOURGET—Engineers at Safran Helicopter Engines have validated the so-called eco-mode hybrid propulsion system destined for Airbus’ rapid and cost-effective rotorcraft (Racer) high-speed helicopter demonstrator.

The eco-mode, designed for twin-engine helicopters, enables one of Racer’s two Safran Aneto engines to be shut down in cruise for better fuel consumption.

Safran announced the ground tests—conducted at the company’s facilities in Bordes, France—on the first day of the Paris Air Show, and ahead of its installation onto the Racer aircraft.

Safran’s electrical system can spool up the second engine quickly for when additional power is required for lower-speed flight, hovering or landing. The system is analogous to that found in modern cars, shutting down the engine when stationary in traffic and restarting it quickly when the accelerator pedal is touched. Safran claims the installation of such a system on twin-engine helicopters could help reduce fuel consumption and carbon emissions from the rotorcraft by around 15%­—as well as provide a boost to the aircraft’s range.

The French manufacturer says the Racer’s eco-mode will use an Aneto-1A engine with a fast-restart electrical system developed jointly with Aquitaine Electronique (AECE Group) and Safran’s Cabin (Ventilation Systems) business.

This system combines an electronic engine control with a high-power-density electric motor, mechanically connected to the engine’s high-pressure section.

The Racer is an evolution of the company’s X³, also known as X-Cubed, approach to high-speed, rotary-wing flight using a combination of box-wing and pusher propellers to drive the aircraft beyond conventional rotorcraft speed and range, but without severe penalties in emissions, noise and operating costs. Target speed is 220 kt. in cruise, with a 25% reduction in cost per mile and a range out to 400 nm.

The aircraft, weighing 7-8 metric tons, is one of two high-speed rotorcraft initiatives being developed through the European Clean Sky 2 aerospace research program—the other being Leonardo’s Next-Generation Civil TiltRotor technology demonstrator.