An unmanned helicopter 10 includes a drive source 36, a tail rotor 20, a shaft unit 38 for transmitting a drive force from the drive source 36 to the tail rotor 20, and an elastic member 64. The shaft unit 38 includes a drive shaft 46, a transmission 44 which transmits a drive force from the drive source 36 to the drive shaft 46, and a transmittal portion 48 for transmitting a rotation torque from the drive shaft 46 to the tail rotor 20. The drive shaft 46 includes a first shaft portion 50a and a second shaft portion 50b. The elastic member 64 is between the first shaft portion 50a and the second shaft portion 50b.