This paper has the objective to present an overview of recent experimental studies conducted in the S3Ch transonic wind tunnel of the ONERA Meudon centre. Experimental investigations have been carried out on a civil transport aircraft power plant configuration to point out the complex wing / pylon / nacelle interference. Control of turbulent buffet phenomenon was performed on a swept wing by means of mechanical and fluidic vortex generators actuators. As a follow up study, the problem of laminar flow over wings in transonic flow conditions was tackled by an in-depth analysis of the shock dynamics in laminar conditions.