Rotor Downwash 2 : The air turbulence occurring under and around the main rotor system(s) of an operating rotary-wing aircraft. Note: Vortex Turbulence
The Canadian Interagency Forest Fire Centre (CIFFC), Glossary of Forest Fire Management Terms, Manitoba, Canada 2003. http://bcwildfire.ca/mediaroom/Backgrounders/2003_ Fire_Glossary.pdf, (For Fr - Canad) {474}