The purpose of COBRA is to use technology breakthroughs to overcome the insufficient noise performance of the counter-rotating fan tested in VITAL FP6 Program. This will be achieved through exploring higher by-pass ratio (15-25) resulting in much lower blade tip speed and blades count. The designs shall comply also with higher or equal aerodynamic efficiency compare to the VITAL ouputs.COBRA is structured to benefit from the existing skills of both EU and Russian partners. It results in multidisciplinary design conception/optimization of the Ultra High Bypass-Ratio (UHBR) Counter Rotating Turbo Fan architecture.COBRA is an ambitious project that aims at meeting the ACARE environmentally objectives, where strong improvements on new engine architecture is required. Based on the current state of the art, and on the complementary skills we gather in COBRA, on the actions planned in the project, the 9 partners take on ambitious and measurable objectives: to reduce noise by 9 EPNdB per operation vs. year 2000 in service engine with the same efficiency improvement as the one achieved in VITAL for lower BPR (~2 / 2.5 points) vs. year 2000 single fan state of the art.The COBRA consortium has been chosen to provide a multidisciplinary expertise, coming from different backgrounds from Europe and Russia Federation: industrial entities, research centers, university and SME. Coordinated by ONERA for the EU side and CIAM for the Russian side, COBRA´s consortium is largely built with former partners from the VITAL WP2.4 project. Following the success of this project, a natural cooperation has been created between partners and consolidated within DREAM FP6 Programme.COBRA leans on a very dynamic consortium, with partners that know each other and therefore shall lead to a reinforced cooperation between European and Russian scientists from different disciplines.