A front attachment device for attaching an aircraft engine to an aircraft pylon includes an upper brace fitted with elements rigidly fastened to the pylon and first and a second connecting rods, each connected to the engine, via a first ball joint connection at one end portion and to the upper brace via a second ball joint connection on the other end portion. The device further includes in each connecting rod a third stand-by link. The first and second connecting rods are interchangeable with each other.