Arrangement for mounting a propulsive system on an aircraft airframe by an external pylon which connects the engine with the airframe, the pylon 4comprising a plurality of spars intruding into the airframe and units for attaching the spars to the internal airframe structure, the cited units being dampers, shock absorbers or active actuators with characteristics chosen so that the units are particularly suited for the efficient reduction of attachment and internal dynamic loads arising mainly but not only from hard landing events and aircraft flight manoeuvres, and for damping sustained vibrations of the propulsive system-airframe assembly, the arrangement allowing the easy removal of the pylon 4 from the rest of the airframe and the interchangeability of the pylon 4 between different aircrafts, being also the cited arrangement tolerant to damage or complete failure of at least one of the spars.