PURPOSE: To rotate a rear fuselage part according to a wind direction, thereby checking any effect of the movement of an aerodynamic center and backwash, and improve the flight performance by halving the fuselage of a flying body longitudinally at the central part in the axial direction, and connecting respective split bodies rotatably around a machine axis at a joint rotational part.

CONSTITUTION: A flying body, for example, a rocket is mounted with a winged flying body 4 at the upper stage part, while two auxiliary boosters 19 are installed in the lower stage part. In this case, a fuselage central part of the rocket is halved in the longitudinal direction, while a front fuselage part 1 and a rear fuselage part 2 are rotatably coupled around a machine axis at a joint rotational part 3. In brief, a surface comprising a main wing of the winged flying body 4 and another surface comprising the machine axis of the auxiliary boosters 19 are parallelled as in illustration (a) or uprighted as in illustration (b) otherwise. With this constitution, an allocation of aerodynamic force, acting on the winged flying body 4, and another aerodynamic force, acting on a rocket lower part, is controlled according to a change of wind direction, through which the rocket is made to aviate in an efficient manner.