The Bell 429 EDAT, which Bell is developing, is a redesigned tail rotor with four small ones in one large one. In addition to being an electric helicopter, it is said that it has contributed to improving fuel economy by adding this structure. In addition, it is said that the effect of reducing noise can be expected.
The helicopter flies in the sky with the power of the large rotor blades and rotors on the aircraft. However, because the single rotor rotates in one direction only, it rotates in the opposite direction by the reaction. So, the tail wing is responsible for stabilizing the aircraft by generating counter torque and rotational force so that the aircraft does not rotate.
There is no need to worry about human injuries because the rotor blades on the upper part of the aircraft are positioned higher than the height of a person. However, since the tail rotor is attached at a right angle of 90 degrees like an exposed fan blade, an accident may occur. Of course, a small rotor located inside the rim like this product can also be expected to prevent such accidents.
429 EDAT (Electrically Distributed Anti-Torque) means anti-torque distributed by power. The role of one tail rotor was distributed to four electric tail rotors. This turns into electricity generated by the main turbine engine. Also, the four wings are driven by independent motors. Even if certain wings fail, the aircraft can remain stable. Related information can be found here .