An aircraft includes a jet engine with a downward deflectable propelling nozzle; an auxiliary power unit with a downward deflectable propelling nozzle; and a transformable wing. The transformable wing includes a fixed wing, hydraulic sleeve, an air intake duct including an upper wall and a lower wall, a thin wing connected to the hydraulic sleeve, a sliding wing, leading edge flaps, trailing edge flaps, an aileron, and a hinge. The transformable wing is configured, during vertical take-off/landing, to transform such that a leading end to an air intake duct in a vertical direction is formed on the fixed wing, and the air intake duct is formed internally in and along a direction of the wingspan of the fixed wing to cause air taken in by the jet engine to flow, in a common direction, over upper and lower surfaces of the thin wing, thereby generating lift for vertical take-off/landing.