Marenco Unveils New Hybrid Helicopter Plan
DALLAS—Swiss-based engineering company Marenco led by Martin Stucki, the creator of the former Kopter SH-09, is seeking investors for a new eight-passenger hybrid electric concept which was unveiled at this year’s Helicopter Association International Heli-Tech in Dallas, Texas.
Dubbed the M12/M22, the helicopter family resembles a larger version of the SH-09—now rebranded the AW09 following its acquisition by Leonardo Helicopters—and incorporates a large multi-role cabin capable of air taxi, firefighting, air medical and cargo missions. Designed to carry an external payload of up to 4,400 lb. at sea level and 3,300 lb. at 10,000 ft., the initial single engine M12 version would be powered by a 1,100 shp turbine/turbogenerator and electrically driven main and tail rotors.
“The idea is basically that you can save a lot of complexity, because you get rid of gearboxes and the tail rotor driveshaft,” says Stucki, CEO of Marenco Swisshelicopter. “The other thing is to be ready for the future because if hydrogen fuel cells or more powerful batteries become available, you already have a platform where you can swap them in or you can also go to a smaller turbine and have more batteries.”
The concept is also inherently safer because it eliminates the mechanical complexity of the gear driven rotors of conventional helicopters, Stucki says. Rechargeable back-up batteries would also provide additional safety he adds. “If you have a serial hybrid drive system you can have a little bit larger battery, and you can give the pilot the ability for the last 20 seconds to have full power in an autorotation,” Stucki says. “Also, in the mountains, even though the whole approach is never a problem, it could give you more power in the last few meters when you need that power availability.”
Although Stucki says talks with investors have only just begun, some initial discussions have taken place with Safran over the possible use of the 1,100-1,300 shp Arrano turboshaft. “We have spoken with Safran about the Arrano which would be quite nice, but there are also other engines available in this class,” he adds.
The design also incorporates a five-bladed main rotor with low disc loading to reduce noise and vibration, and a shrouded tail rotor which Marenco says could potentially be turned off for forward flight. The hybrid drivetrain could also enable variable rotor speeds, helping reduce noise levels. The designers believe the M12/M22 could be operated just on electrical power over noise sensitive areas.