As there are only photographs on the first page of RENDERosity's aviation gallery now, I'm gonna post another one, too. Recently, we are playing around with a helicopter model in the wind tunnel. Where the battery back should be, there is now an internal balance holding the vehicle in place on the mounting sting. Doing experiments with rotary aircraft, there are some more parameters to consider than just the angle of attack, as it is the case for fixed wing aircraft. In order to ensure similarity to stationary free flight conditions, angle of attack, collective and cyclic pitch angle and the velocities of blade tips and mean flow have to match in a way that all forces and moments are zero except for the desired lift. We are just learning how to get this done ... Special thanks to -> Giovanni Campana, SAB Heli Division s.r.l., San Mauro Pascoli (http://www.sabitaly.it) -> Mario Hauffe, Heli-doc DD, Weinböhla (http://www.heli-coc-dd.de) -> Silke Wörner, Kontronik + SOBEK GmbH (http://www.kontronik.com) -> Denis Eichler, TU Dresden, Student -> The whole wind tunnel staff http://tu-dresden.de/ilr/nwk The Wheelchair-General Canon HF-100 Corel Photopaint 7