Silent aircraft takes flight

NEW YORK — A nearly silent, drone-sized aircraft has shown it can fly, thanks to a scientist who was inspired by watching Star Trek as a kid.

With neither propellers nor jets, the airplane gets its thrust by applying a strong electric field to the air. That general idea has been demonstrated at science fairs, but the new work shows it can power a free-flying airplane. So can people look forward to travelling in planes that are almost silent and emit no air pollution?

“Not anytime soon,” says Steven Barrett of the Massachusetts Institute of Technology, who reported the results in a study released Wednesday by the journal Nature.

It’s not clear whether the technology could work at such a large scale, he said. And even if it can, it would take a few decades to develop such planes, he said.

The Nature paper reports the results of 10 test flights inside an MIT athletic building. With a wingspan of about five metres, the 2.45-kilogram plane sailed along at about 17 km/h. Each flight covered about 55 metres.

The MIT airplane flies using “ionic wind” – a series of thin wires at the front of the plane generate a powerful electric field. The field strips electrons from air molecules, turning the molecules into positively charged particles called ions.

Those ions flow toward negatively charged parts of plane, colliding with ordinary air molecules and transferring energy to them. That produces a wind which provides thrust for the plane.