Abstract: One embodiment is an apparatus for inhibiting accidental contact by a human with a tail rotor connected to an empennage of an aircraft. The apparatus includes an inverted V-tail connected to an empennage of the aircraft forward of the tail rotor, the inverted V-tail stabilizer comprising a first V-tail stabilizer on a side of the empennage to which the tail rotor is connected and a second V-tail stabilizer on a side of the empennage opposite the side of the empennage to which the tail rotor is connected; and a shroud bar having a first end connected to an outboard end of the first V-tail stabilizer and a second end opposite the first end connected to the empennage aft of the tail rotor, wherein a horizontal distance from the shroud bar to the tail rotor is greater than a length of an arm of the human.

Abstract: In some examples, an aircraft comprises an airframe, a rotor system coupled to the airframe, and a vibration attenuation system. The rotor system is operable to exert a vibratory force on the airframe. The vibration attenuation system comprises two or more batteries and elastic devices. The two or more batteries are operable to supply power to the rotor system. The elastic devices coupled to the two or more batteries and the airframe. The elastic devices are configured to attenuate the vibratory force based on facilitating oscillation of the two or more batteries. In other examples, a method comprises coupling elastic devices to two or more batteries and an airframe of an aircraft. The elastic devices receiving a vibratory force via the airframe and attenuate the vibratory force based on facilitating oscillation of the two or more batteries.

Abstract: In some examples, an aircraft comprises an airframe, a rotor system coupled to the airframe, and a vibration attenuation system. The rotor system is operable to exert a vibratory force on the airframe. The vibration attenuation system comprises two or more batteries and elastic devices. The two or more batteries are operable to supply power to the rotor system. The elastic devices coupled to the two or more batteries and the airframe. The elastic devices are configured to attenuate the vibratory force based on facilitating oscillation of the two or more batteries. In other examples, a method comprises coupling elastic devices to two or more batteries and an airframe of an aircraft. The elastic devices receiving a vibratory force via the airframe and attenuate the vibratory force based on facilitating oscillation of the two or more batteries.