Off-target pesticide spray-drift is recognised as a source of contamination of the environment and presents a risk to water courses, operators and bystanders. Single-nozzle tests in 'small` wind-tunnels are relatively cheap and easy to perform compared to full-scale equivalents. In the case of trailed axial-fan air-assisted sprayers, the machine`s impact upon spray drift is much more significant than for arable boom sprayers: due to the interaction of the high air-jet velocity with both vine structure and wind. The question is: "Does the single-nozzle typical wind-tunnel drift characterisation developed for boom-sprayers bear any relation to the air-blast sprayer case?" The Jules Verne Thermal Circuit Wind-tunnel, provided a facility large enough to investigate this; whilst obtaining an experimental dataset for the calibration and development of models. As an assessment of full-scale drift from a broadcast air-assisted sprayer, fitted with various nozzle types; this work has yet to be assessed against at least three criteria. Firstly, how does the data-set compare to those from isolated non air-assisted single-nozzles in relatively smooth boundary layers and no crop structure? Secondly, does it provide a data-set suitable for modelling with Computational Fluid Dynamics from which extrapolation to more realistic field conditions can be made? And thirdly, does it bear comparison with full-scale field data?