BUTERFLI is a project in response to the invitation to tender from European Commission FP7 within Call FP7-AAT-2013 RTD-Russia.BUTERFLI is the acronym of BUffet and Transition delay control investigated within Europe-Russia cooperation for improved FLIght performances. The Project Topic will focus on experimental and numerical flow control investigations of different phenomena: the buffet on a laminar airfoil, the buffet on a turbulent supercritical airfoil, and the cross-flow instabilities on a swept wing. Different control techniques will be studied: bump design, fluidic control devices, and DBD devices. The Project aims at the improvement of aircraft flight performances.This Project will be carried out in the framework of a EUROPE – RUSSIA cooperation. ONERA is the coordinator, and TSAGI will act as Coordinator of the Russian Partners.There are 12 partners, 7 from Europe and 5 from Russia.ONERA (F), IAG-Stuttgart (G), DLR (G), KTH (S), University of Nottingham (UK), EADS UK Ltd. (UK), TsAGI (Russia), MIPT (Russia), JIHT (Russia), ITAM (Russia), Sukhoi Civil Aircraft (Russia), and Erdyn (F).BUTERFLI is splitted into four work packages:WP1 is dedicated to buffet control on 2D turbulent supercritical wing (tangential jet blowing and plasma actuators)WP2 is dedicated to buffet control on 2D laminar wing (bump and perforation blowing)WP3 is dedicated to crossflow instabilities control on swept wingWP4 ensures the scientific coordination of the overall project, and will proposes final roadmaps for the future.