For gains in terms of aerodynamic performance levels, an aircraft engine assembly includes a turbomachine, a fastening strut for the turbomachine, and at least one foldable ventilator cover which surrounds the turbomachine and which includes: a first cover sector which includes a first end portion which is mounted so as to be articulated to the fastening strut, along a first articulation axis, and a second cover sector which includes a first end portion which is mounted so as to be articulated to a second end portion of the first cover sector, along a second articulation axis parallel with the first articulation axis. The second end portion is mounted so as to be guided at one side and the other thereof by a thrust inverter cover of the engine assembly and an air inlet structure of this assembly, respectively.