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In search for deviations from homologous expansion in planetary nebulae wepresent a 3D morphokinematical model of NGC 7009. The model has beenconstructed with {\em Shape} based on PV diagrams from the literature and HSTimages. We find that the data are consistent with a radial velocity field withincreased gradient at high latitudes compared to the equatorial region (Model1). In a second model we assume a linearly increasing radial velocity componentwith an added poloidal component of order 10 km/s at latitudes around$70^\circ$. The true velocity field is likely to be in between these twolimiting cases. We also find that the expansion of the ansae is non-radial withreference to the central star. Their velocity field is focused near theapparent exit points from the main shell. We predict the proper motion patternfor the model with a non-zero poloidal velocity component.

The 3D velocity structure of the planetary nebula NGC 7009