Bell helicopter company has revealed an experimental 429 helicopter that uses four electric-motor-powered tail rotors.
Instead of conventional single high-speed tail rotor to counteract the torque of the main rotor, the 429 uses Electrically Distributed Anti-Torque (EDAT) tail rotors for the first time.
The “Electrically Distributed Anti-Torque” system, or EDAT is for short, composed of four small variable-speed propellers embedded within a tail rotor shroud in an offset two-by-two pattern.
Each of the rotors contains four blades, and they are powered by four separate motors, with the electrical energy provided through generators driven by the turbine engines.
“We got rid of all the mechanical linkages that change the pitch of the blades and replaced them with electric wires,” Bell program manager Eric Sinusas said. “We realized that we don’t actually need that driveshaft and gearbox that we’ve had for the last 80 or so years.”
The EDAT technology is safer than a conventional tail rotor assembly because it stops moving once the aircraft is on the ground.
It also costs less to operate, has fewer mechanical components and is significantly quieter.