A multi-engine aircraft having one engine positioned at the tail of the fuselage may include rear tail units in a vertical longitudinal plane-of-symmetry of the fuselage. The tail engine is disposed in front of the rear tail units on the upper part of the tail of the fuselage. The tail engine is mounted, in a detachable manner, on a rigid supporting structure attached to the supporting structure of the fuselage. A lowering shaft, formed in the tail of the fuselage and plumb with the engine, is supported by the rigid supporting structure. The lowering shaft provides a passage for the engine between a high position corresponding to the operational position of the engine and a low position in which the engine is removed from the fuselage.