Test flights of a new system allowing twin-engined helicopters to operate using just one powerplant, as a fuel-saving measure, could take place within months, according to French turboshaft manufacturer Turbomeca.

Airbus Helicopters earlier this year unveiled a similar initiative using the Pratt & Whitney Canada PW206B engines on its Bluecopter eco-demonstator, which it refers to as a single-engine operation (SEO). The airframer claimed the system could offer a fuel saving of around 25%.

However Turbomeca is working on its own initiative to allow one engine to be put into “sleep mode” during suitable stages of the flight, says Philippe Couteaux, executive vice-president for strategy and development at the Bordes-based firm.

Although dismissive of Airbus Helicopters’ claims of double-digit fuel savings in real-world conditions – due to a relatively limited proportion of flights when SEO could be employed – Turbomeca is nonetheless developing a system “because we believe there’s a potential benefit for certain missions on certain aircraft.”

Key to its success is the ability to “restart, with full reliability, as quickly as possible” the idled engine, says Couteaux.

Turbomeca has, since June, been testing an electric restart system installed on what it describes as a 2,500shp-class (1,860kW) engine, likely to be one of its Makila models.

No results have so far been released, but Couteaux says the demonstrations have proved it to be “several times faster than any conventional starting device.”

Couteaux says the company has proposed the concept to all the major airframers, with a few to moving to a flight-test phase, adding: “We are discussing with our customers. All have expressed interest. There’s not a specific timeframe, but it is months rather than years.”

The ideal helicopter would be a larger model, he says, due to there being more opportunities to employ the system on flights with longer cruise segments.

Of the rotorcraft currently in production, only the Airbus Helicopters AS332 and H225 use the Makila engine.

Source: FlightGlobal.com