The Flight Experiments (FX) facility of DLR operates the largest fleet of civil research airplanes and helicopters in Europe. FX comprises Research Flight departments in Braunschweig and Oberpfaffenhofen, as well as a nationally and EASA approved Design Organisation. FX operates aircraft which are highly modified for research purposes. These aircraft serve either as a platform for installation of scientific equipment for various purposes, such as earth observation or atmospheric research, or they are in the focus of aeronautical research themselves. This contribution intends to give an overview on DLRs different aircraft platforms, their capabilities and typical applications.