New Helicopter Design Trades Tail Rotors for Electric Fans

A new helicopter design could be safer, quieter, and help usher in electric-powered flight.

The Electrically Distributed Anti-Torque system (EDAT) from helicopter manufacturer Bell ditches the noisy (and inefficient) tail rotors for four electric fans. As the name implies, EDAT involves four independent electrically-powered motors (via generators), and right away, this solves a huge problem with conventional copters.

Tail rotors are only needed for hovering and low-speed flight, but they’re constantly active because they’re linked to the main engine. Bell Model 429’s EDAT is a fly-by-wire system, and not only can the computer take over their function – paving the way for future autonomous systems – but the pilots can actually switch them off for forward flight.

“We got rid of all the mechanical linkages that change the pitch of the blades and replaced them with electric wires. We realized that we don’t actually need that driveshaft and gearbox that we’ve had for the last 80 or so years,” said Bell program manager Eric Sinusas.

The fans operate at variable speeds and because they’re “changing RPM constantly,” their acoustic signature is much lower than conventional helicopter design. This is a big deal for civilian noise pollution, but it’s also extremely attractive to one particular customer – the military.

Even the stealthiest military helicopters still have to deal with pesky (and noisy) tail rotors, but EDAT potentially opens up a ton of strategic possibilities.

Of course, the Bell 429 is still very much in the testing phase, and the actual model might never see the light of day, but the tech is more than a little intriguing.

See more here: https://www.wired.com/story/bells-design-helicopters-quieter-safer/