To improve workability of a work outside a rotorcraft by a hoist and to reduce the generation of air resistance by a method wherein skids are arranged below a rotorcraft vertically to a rotorcraft shaft in such a state to be separated away from each other in the longitudinal direction of the rotorcraft shaft and a work outside the rotorcraft is effected between the skids.

Stays 2 each having an upper end fixed at the rotorcraft body structural material of the bottom of a rotorcraft 1 are protruded downward. Skids 3 are fixed at the lower ends of the stays 2 in a direction crossing the advancing direction F of the rotorcraft 1. Further, a weight object lifting device, such as a hoist 4, to effect a work outside the rotorcraft is mounted on the vicinity of the center of gravity of the rotorcraft 1. The skids 3 are arranged in such a manner that the arrangement position of the hoist 4 is positioned approximately at a central part therebetween and properly separated away from each other in the longitudinal direction of the arrangement position of the hoist 4. This constitution prevents a hoist work from being impeded by the skids 3.