MIT says its aircraft is silent, lightweight and doesn’t depend on fossil fuels or batteries.
MIT engineers have built and flown the first-ever plane with no moving parts. Instead of propellers or turbines, the light aircraft is powered by an “ionic wind” — a silent flow of ions that is produced aboard the plane, and that generates enough thrust to propel the plane over a sustained, steady flight.
Unlike turbine-powered planes, the aircraft does not depend on fossil fuels to fly. And unlike propeller-driven drones, the new design is completely silent, MIT says.
Steven Barrett, associate professor of aeronautics and astronautics at MIT, said: “This is the first-ever sustained flight of a plane with no moving parts in the propulsion system. This has potentially opened new and unexplored possibilities for aircraft which are quieter, mechanically simpler, and do not emit combustion emissions.”
He expects that in the near-term, such ion wind propulsion systems could be used to fly less noisy drones. Further out, he envisions ion propulsion paired with more conventional combustion systems to create more fuel-efficient, hybrid passenger planes and other large aircraft.
Inspired by Star Trek
Barrett says the inspiration for the team’s ion plane comes partly from Star Trek, which he watched as a child.
“This made me think, in the long-term future, planes shouldn’t have propellers and turbines,” Barrett says. “They should be more like the shuttles in Star Trek, that have just a blue glow and silently glide.
“Ionic wind”, also known as electroaerodynamic thrust, was first identified in the 1920s and describes a wind, or thrust, that can be produced when a current is passed between a thin and a thick electrode. If enough voltage is applied, the air in between the electrodes can produce enough thrust to propel a small aircraft.
For years, electroaerodynamic thrust has mostly been used by hobbyists, and designs have for the most part been limited to small, desktop ‘lifters’ tethered to large voltage supplies that create just enough wind for a small craft to hover briefly in the air. It was largely assumed that it would be impossible to produce enough ionic wind to propel a larger aircraft over a sustained flight.
“It was a sleepless night in a hotel when I was jet-lagged, and I was thinking about this and started searching for ways it could be done,” Barrett says. “I did some back-of-the-envelope calculations and found that, yes, it might become a viable propulsion system. And it turned out it needed many years of work to get from that to a first test flight.”
Ions take flight
The team’s final design resembles a large, lightweight glider. It weighs about five pounds and has a five-metre wingspan.
The team recently flew the plane in multiple test flights across the gymnasium in MIT’s duPont Athletic Center — the largest indoor space they could find to perform their experiments. They flew the plane a distance of 60 metres (the maximum distance within the gym) and found the plane produced enough ionic thrust to sustain flight the entire time. They repeated the flight 10 times, with similar performance.
“This was the simplest possible plane we could design that could prove the concept that an ion plane could fly,” Barrett says. “It’s still some way away from an aircraft that could perform a useful mission. It needs to be more efficient, fly for longer, and fly outside.”
Barrett and his team at MIT have published their results in the journal Nature.