Tucked in between the jumbo jets and military demonstrations at the Paris Air Show this week is a small motorglider powered by the first serial hybrid electric drive found in an airplane. The innovative plane is essentially an airborne Chevrolet Volt, with an electric motor turning the prop and a gasoline engine providing juice when the battery dies.

Like the Chevrolet Volt, the DA36 E-Star was designed for maximum fuel efficiency. Siemens developed the composite two-seater with aerospace giant EADS and Diamond Aircraft of Austria. The company hopes the technology easily can be scaled up to suit larger aircraft.

“We want to cut fuel consumption and emissions by 25 percent,” Dr. Frank Anton of  Siemens said in a statement.

Beyond reducing fuel consumption, the hybrid drive can also greatly reduce noise heard by people on the ground.

The noisiest part of a typical flight occurs during takeoff, when airplanes use their maximum power. Serial hybrid drive allows the pilot to takeoff under electric power, greatly reducing the overall noise heard by those on the ground — and in the aircraft, as we discovered while flying an electric airplane last year.

Under the cowling of the DA36 E-Star shows the serial hybrid electric drive.

The demonstrator in Paris completed its first flight in Austria on June 8. It features a 94-horsepower Siemens electric motor to drive the propeller. The batteries provide juice during takeoff and climb. Once the plane is cruising, a relatively modest 40-horsepower Wankel rotary engine drives a generator that keeps electricity flowing to the motor.

Like other electric aircraft, the DA36 E-Star can’t carry a large — and heavy — battery pack, which limits the craft’s ability to run purely on battery power. Siemens is working on the next generation motor, which the company expects to be significantly lighter. Other drivetrain improvements, as well as the improvements in battery tech everyone hopes for, should bring further reductions in fuel consumption.

Like their automotive cousins, electric aircraft are still striving for extended range. Battery-electric aircraft can achieve flights of more than hour, a significant milestone because it allows for the possibility of using electric airplanes for flight instruction. Because of the weight of the batteries, there are  limitations to dramatically extending the range using only battery power based on what is currently available.

Back in 2008, Boeing used a similar motor glider from Diamond Aircraft as a test bed for a hydrogen fuel cell airplane. Two years later the aviation giant unveiled a hydrogen-powered unmanned aircraft designed for military use.

None of the companies involved with DA36 E-Star announced any specific plans for the new drivetrain beyond saying it will be used in large-scale aircraft some time in the future.

Photos: Siemens