Until relatively recently most designs of helicopter, including the Westland Wessex on which the tests described in this paper were made, used the NACA 0012 profile for the main rotor blades. Profiles designed specifically ...

Experiments have been made to determine the flow conditions through a helicopter rotor in forward flight using the smoke filament technique. This method consisted of flying the helicopter behind an aircraft from which smoke ...

Flight tests have been made on a Hoverfly I helicopter to investigate the types of flow associated with various rates of vertical descent. At the same time measurements of the performance were made. The results are analysed ...