The basis of such sensor has been elaborated in the EU project I-Wake (Instrumentation systems for on-board wake vortex and other hazards detection, warning and avoidance). Thereby, the pulsed Doppler lidar developed by the DLR Institute of Atmospheric Physics has been installed in the Cessna Citation aircraft of NLR (The Netherlands), together with the scanning device from the Fraunhofer Institute for Applied Optics and Precision Engineering IOF (Jena) and the data acquisition unit of Thales-Avioniques (France). With this instrumentation, both the wake vortices of an A340 test aircraft and the wind shear occurring in the vicinity of the Pyrenees have been successfully detected during a field experiment in Southern France. On the basis of the gathered experiences, the next step has to be the development of the prototype of a forward looking detection and warning sensor together with partners from industry. Air-traffic experts are predicting such lidar-based sensors increasing importance since they can help to reduce capacity bottle-necks without violating the high safety standards.