PURPOSE: To improve airdrop safety by rotating a fuselage tail section with a stability airfoil including a roll rudder angle when an airdrop from a mother plane is detected and sliding the fuselage tail section containing the stability airfoil backwards to the fuselage by a ball screw.

CONSTITUTION: After airdropped from a mother plane, a stability airfoil section composed of a plurality of stability airfoils 2, a fuselage tail section 3 and a ball screw shaft 4 rotates by the roll moment of a stability airfoil 8 taking a roll rudder angle because a stopper 6 comes off by a wire 7 and it becomes freely rollable. Thus aerodynamical stability is improved by a fuselage 1 sliding backward of the axis by the screw length by the action of the ball screw shaft 4 and a fuselage side nut 5 and the point of application of aerodynamics of the whole fuselage moving largely to the back. Consequently safety of airdrop from an aircraft can be upgraded.