When a coherent circular stream of small non-cohesive particles impacts onto a smooth inclined surface, it is dispersed as a thin sheet. The particles appear to move down the plate parallel to the plate surface on paths which straighten to run parallel to the longitudinal axis of the plate at points remote from the impact point. Interest in the post-impact behaviour of a falling particle stream was prompted by its potential use in mixing devices and in removing oversize material from bulk flows. Experimental measurements carried over a range of conditions have provided information on the shape, structure and mass distribution in an impact fan. A mathematical model has been formulated and a comparison has been made with one experimental condition. The agreement between measured fan shapes and mass distributions and model predictions is good.