The antitorque drive system consists of an antitorque drive shaft and a antitorque transmission mounted at the end of the tail boom. The drive shaft may consist of one long shaft or a series of shorter shafts connected at both ends with flexible couplings. This allows the drive shaft to flex with the tail boom. The tail rotor transmission provides a right angle drive for the tail rotor and may also include gearing to adjust the output to optimum tail rotor rpm. Tail rotors may also have an intermediate gearbox to turn the power up a pylon or vertical fin.
The tail rotor driveshaft is connected to both the main transmission and the tail rotor transmission.
