An aircraft which is configured for vertically ascending and landing, includes at least two wings (2a, 2b, 4a, 51, 4b, 52), a space (2c, 4c) for the generating during operation of climbing power, and an intermediate portion (3), the intermediate portion (3) being provided with thrust motors (6), and the space (2c, 4c) for the generating during operation of climbing power being provided with a quantity of lifting power units (HV). Each lifting power unit includes a first variable volume (V1) for the storage of an amount of relatively light gas which is lighter than atmospheric air, and is configured for the controllable adjustment of an upward force or lifting power by the variable volume taken up by the amount of relatively light gas.