Please select the most similar patent number from A, B, C and D. Which number is?
A vertical take-off and landing aircraft with tiltrotor power for use on land and in the air comprising: a body (3) equipped with a driving device, controlled wheels (8) for allowing the body to move on the ground, a front thruster (1) and a rear thruster (2) for controlling the flight of the body or the take-off and landing thereof, transmission support rods (5) provided on the two sides of the body, a first pivot shaft (9) laterally passing through the body, with the first pivot shaft connected with the transmission support rods on the two sides of the body; the front thruster is fixedly connected to the front ends of the transmission support rods, and the rear thruster is fixedly connected to the rear ends of the transmission support rods; and the central axes of the front and rear thrusters are perpendicular to the plane formed by the two transmission support rods. By controlling the rotation angles of the front and rear thrusters, the aircraft has the major basic functions of both vertical take-off and landing as well as horizontal flight, and achieves a simple conversion between driving on land and flying in the air. During flight, the body of the aircraft always remains in a horizontal state, so that the drivers and passengers feel comfortable and have a wide field of vision, facilitating safe driving.
A: A foldable-wing flying automobile adopting a serial type pneumatic layout comprises an automobile body (1), wheels (2) installed on a lower part of the automobile body, main wings installed on two sides of the automobile body and capable of generating an upward lifting force, and a thruster (17) installed on the automobile body and capable of generating a thrusting force. Both front wings (3) and back wings (6) are the main wings with a large wing area and a long wingspread. When the wings of the flying automobile are spread, the front wings and the back wings form a longitudinal serial type pneumatic layout along the automobile body, and together generate the upward lifting force. When the wings of the flying automobile are retracted, the front wings are turned over, folded, and then received at the two sides of the automobile body, and the back wings are turned over, folded, and then received at the top of the automobile body or at the two sides of the automobile body. The wings and the automobile body are installed with solar cell panels (20) with a large area, so that the whole automobile becomes a large solar charger, thereby enhancing an endurance capability. In the present invention, based on the foregoing, a vertical takeoff and landing airplane automobile and a flying automobile for over-water, ground, and air traveling are further realized.
B: Disclosed is a hand-held underwater aircraft, comprising a battery compartment (12) and propellers. A special design with the axis of the propellers being unparallel with the axis of the battery compartment is adopted, the unparallel included angles make the component forces generated by various propellers in the direction of motion of the non-underwater aircraft offset each other, and enable the underwater aircraft to maintain balanced and straight-forward motion. The design of unparallel axes of the propellers and the battery compartment (12) leads to a little power loss, but avoids larger power loss caused by the impact of water on the human body, thereby comprehensively improving the thrust of the underwater aircraft in use. The design of unparallel axes of the propellers and the battery compartment (12) leads to a little power loss, but avoids larger power loss caused by the impact of water on the human body, thereby comprehensively improving the thrust of the underwater aircraft in use. Moreover, the water does not strike on the user&#39;s face, thereby effectively preventing the user from inhaling water, making the user feel more comfortable and safer, and effectively improving the overall use experience.
C: The present invention relates to a vertical take-off and landing aircraft, comprising a fuselage (1), a main wing, a main thrust apparatus (2) that can tilt between the horizontal position and the vertical position, a tilt apparatus that enables the main thrust apparatus to tilt, and an attitude control apparatus for controlling the flight attitude; the wing comprises a left wing and a right wing, and the main thrust apparatus uses a heat engine as the power apparatus; the invention is characterized in: the attitude control apparatus consists of at least two attitude-adjusting apparatuses (4), a power module (5), a speed adjustment module (9), and a flight control system (6); an attitude-adjusting apparatus consists of a motor (4a) and a propeller or a ducted fan (4b) that has a power connection with the motor; at least one attitude-adjusting apparatus is provided on the left wing, and at least one attitude-adjusting apparatus is provided on the right wing. The mechanical structure of the aircraft is thereby simplified, the reaction is more rapid and sensitive, and the operation is easier, thereby further stabilizing the aircraft attitude control.
D: A handheld underwater flying vehicle, comprising a battery compartment (12) and propellers. The quantity of the propellers is at least two, and the propellers are symmetrically arranged on two sides of the battery compartment (12) and connected to the battery compartment (12). The axis of the propellers and the axis of the battery compartment (12) have a special non-parallel design. The angle of the non-parallelism causes the component forces produced by the propellers not in the movement direction of the underwater flying vehicle to cancel each other out, and causes the motion of the underwater flying vehicle to remain balanced, allowing for travel in a straight line. The non-parallel design of the propeller axes and the battery compartment (12) axis causes a very small power loss, but avoids a greater power loss caused by water flow striking a person&#39;s body, improving forward thrust of the underwater flying vehicle overall during use. Because water does not strike the user&#39;s face, the user is also prevented from choking on water, making the user more comfortable and safe, and improving the overall use experience.
Answer: C