Despite the considerable difficulties encountered in developing a stable parabolized Navier-Stokes (PNS) algorithm the versatility of the PNS model makes it increasingly attractive as a prediction tool for supersonic viscous flows. Physically, the PNS model is obtained by neglecting the streamwise molecular transport within the NS equations. Two possibilities that arise are: only the diffusion in the direction normal to the body surface is considered; or the circumferential diffusion is also included. In the work of S. C. Lubard and W. S. Helliwell, the question of subsonic sublayer regularization was addressed in connection with cones at angle of attack. The Lubard-Helliwell method was applied to a series of simple geometries, such as spherically blunted cones at angle of attack, ogive cylinders, spinning sharp and blunt cones, a blunt biconic, a 35° swept wing; invariably, the bluntness region flow was assumed to be axisymmetric and the pressure distribution was derived from a corresponding inviscid analysis.