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1 . ENSICA first focused its work on the numeric conditions for successful simulations : ele ment hypotheses and material models available, meshing limitations and constraints, sta ble FSI formulation, results available. CEV provided then only analysis cases. In 2003, CEV acquired the same software an started running simulations with a new purpose : its computing power was not enough to model parachutes and airflow with the required precision and current techniques (ENSICA had had to restrict to a quarter model with symmetry conditions) ; the work was then oriented to prototype or specify new simulation features that w ould eventually lead to the full scale simulation of a parachute or event a cluster of par achutes. The main result of its work was a new formulation of the fluid properties and boundary conditions that made possible the use of non-parallelepiped fluid element, allowing the m inimisation of the fluid elements count with a butterfly-type mesh. The simulations of full model parachutes were then fast enough to allow several simulation cases a month, with acc eptable if not optimum accuracy. One of these simulations was then used to demonstrate the necessity to develop a new FSI feature in the finite element analysis software : initiates of the FSI initially thought the existing porosity simulation feature was suitable for parach ute simulation. In fact it had been designed for airbag simulation, closed and surrounded by ambient atmosphere, which allows to delete the leaking gas from the simulation. In p arachute simulation it is necessary to restore the leaking gas on the outer face of the fa bric. In 2004, CEV demonstrated the interest of such a feature based on Ergun's law and got help from the former LS-DYNA developer M'Hamed Suli to demonstrate its feasibility with minimal changes to the software, and wrote a common proposal with Irvin Aerospace for LSTC (the developer firm) to implement it in a new version. The official release of version 971 makes the feature available for all users, and allows new developments in ENSICA for more accurate simulations, based on the cases defined in CEV.