AMEVoice

The latest step in fuel cell flight has taken to the skies with the world’s first hydrogen helicopter flew for more than 20 minutes. The technology demonstrator developed by United Technologies Corp. features a proton exchange membrane fuel cell.

There’s one small catch — the helicopter has a rotor diameter of two meters only. The remote control helicopter was designed to run on batteries. UTC modified it to use a fuel cell, and the flight was made entirely with hydrogen. Despite the small size of the aircraft, Dr. David Parekh of UTC called it a significant step forward because of the unique challenges of helicopter flight.

“Achieving vertical flight represents a key milestone in fuel cell-powered flight as the power density requirements are much greater than for fixed wing aircraft,” he said.

Some fuel cell-powered flights with full size, piloted aircraft, including one funded by Boeing already flown. But as Parekh notes, power requirements for vertical flight are much harder than for fixed-wing craft. The fuel cell powered aircraft flown to date have more glider like wings, adding to their efficiency advantage.

A video on UTC’s website shows the small remote-controlled helicopter during its first flight last month. The company says the maximum power was 1.75 kilowatts. For comparison, the Antares fuel cell aircraft only requires 10kW and is piloted by a person. Energy density from the power system exceeded 500 W/kg, exceeding the energy density of a typical lithium ion battery setup.

The company plans longer flights in the near future, but there are no plans yet for a manned hydrogen fuel cell helicopter.