Radio-controlled flying apparatus

A radio-controlled flying apparatus comprising:

• an annular buoyant body containing a gas therein which gives a buoyant force to said annular buoyant body, said annular buoyant body having a center of buoyant force at its geometrical center;
• a main body supported by said annular buoyant body by means of a dual-axis gimbal;
• a pair of propellers which rotate in opposite directions;
• a rocking mechanism for causing said main body to rock about the dual-axis gimbal, said rocking mechanism including
• (i) first rod and a second rod which cross at their middle portions substantially at a right angle, each of which being connected at two ends thereof to said buoyant body through connecting members,
• (ii) a first servo motor mounted on said main body and drivingly connected at an output shaft thereof to said first rod such that the first servo motor moves relative to said first rod along the longitudinal direction of said first rod to cause said main body to rock about said dual-axis gimbal when said first servo motor is operated, and
• (iii) a second servo motor mounted on said main body and drivingly connected to an output shaft thereof to said second rod such that the second servo motor moves relative to said second rod along the longitudinal direction of said second rod to cause said main body to rock about said dual-axis gimbal when said second servo motor is operated;
• variable-speed motors for driving said pair of propellers into rotation;
• an electric circuit for receiving a radio wave from an external transmitter, said radio wave carrying control information for controlling said rocking mechanism and variable-speed motors;
• and
• a battery for supplying an electric power to electric components,
• wherein said buoyant body is positioned such that said flying apparatus has an overall center of gravity at a position below said center of buoyant force of said buoyant body.