An aircraft (1) comprising a fuselage (2), a rotary wing (10) having two contrarotating main rotors (12) arranged in tandem above the fuselage (2), at least one propulsion member (20), and a power plant (30). Each propulsion member (20) is carried by a rear portion (3) of the fuselage. The aircraft (1) includes an interconnection system (40) providing a permanent connection between the power plant (30) and the rotary wing (10), except in the event of a failure or during training, the aircraft (1) having differential control means (50) for controlling the cyclic pitch of the blades of the main rotors (12) to control the aircraft (1) in yaw, and inhibition means (60) for inhibiting each propulsion member (20).