Sikorsky recharged

Having grown up in an aviation family, Chris Van Buiten remembers well the 1983 film “Blue Thunder,” including the scene in which the stealthy, title police helicopter materializes seemingly out of thin air to surprise the bad guys.

Not to steal Van Buiten”™s thunder, but his employer may deliver surprise breakthroughs on stealth technology sooner than one might think.

United Technologies Corp. and subsidiary Sikorsky Aircraft Corp. are exploring the use of electric propulsion to power helicopter flight, which would offer several advantages including noise abatement, a particularly appealing proposition for the U.S. military which uses Sikorsky helicopters on missions in which the element of surprise is crucial.

Other obvious advantages include reduced costs due to lesser fuel consumption, and decreased chances of crashes stemming from mechanical failures in combustion-based engines.

Van Buiten leads Sikorsky Innovations, which Stratford-based Sikorsky unveiled in February as its arm for advanced helicopter research. Speaking at last month”™s SBIR National Conference in Hartford, Van Buiten listed three areas of innovation at Sikorsky as it seeks new heights in helicopter technology: speed, as illustrated by the Sikorsky X2 prototype that aims to set a speed record this summer; autopilot and remote control functionality that would allow for unmanned flights; and mission adaptability, which would allow pilots at the flip of a switch to optimize rotor configurations for a range of purposes, including speed, lift and muted noise.

Sikorsky is not yet talking in public forums about another stealthy option: electric propulsion. Queried by a reporter, Van Buiten confirmed the company is investigating the use of hybrid and electric engines for flight. And earlier this year, Van Buiten confirmed to Aero-News Network that Sikorsky is working on a “skunk works”-style project dubbed Firefly, which could possibly be a reference to electric technology in propulsion.

“Maybe you”™ll see some Firefly stuff this year,” Van Buiten said. “I wish we could talk about it more, but we”™re not going to right now.”

Firefly also involves Sikorsky”™s sister UTC division Pratt & Whitney and U.S. Hybrid, a California-based company that specializes in power conversion systems for hybrid vehicles, according to a report in the trade publication Flightglobal, which did not disclose its sources.

A month ago, the GE Aviation subsidiary of Fairfield-based General Electric announced it had received a $7.6 million grant from the state of Ohio to create an electric-power research and development lab in Dayton that will, among other projects, research the development of “more electric aircraft” without specifying how far it could take the concept. GE Aviation engines are used on Sikorsky helicopters. The lab will be near Wright-Patterson Air Force Base and its Air Force Research Laboratories, with which East Hartford-based Pratt & Whitney is also working on advanced aircraft propulsion technologies.

In the meantime, other organizations are showing that electric propulsion for flight may not be science fiction much longer. NASA is currently readying an experimental one-man aircraft dubbed Puffin that would take off vertically like a helicopter, with the operator than “leaning” the vehicle to a horizontal position to fly like a prop plane. And a British company called Falx Air Vehicles has envisioned tilt-rotor technology akin to the V-22 Osprey built by Boeing Co. and Bell Helicopters, but powered by a hybrid electric engine.

Both aircraft are unsuitable for the types of heavy-lift missions that represent Sikorsky”™s bread-and-butter business, however. To get any serious consideration from the Pentagon, Van Buiten said, an electric or hybrid-electric helicopter would have to be able to carry a minimum of four people and equipment one hour. The best electric batteries conceivable today would be drained after just five minutes of helicopter flight, he added.

Still, Van Buiten notes Sikorsky and UTC engineers can take inspiration from founder Igor Sikorsky, who in 1939 managed vertical takeoffs and landings lasting just minutes aboard his VS-300, the first American-built helicopter to achieve flight. It took Sikorsky less than two years to engineer the VS-300 to remain aloft for nearly 90 minutes.