Major infall model for galaxy 1: the radial infall velocity of galaxy 1 onto galaxy 2 can be determined from the projection of the radial infall velocity and the line-of-sight velocity of galaxy 2 onto the line-of-sight of galaxy 1. An analogous procedure yields the major infall model for galaxy 2. Due to the asymmetry of this model, both radial infall velocities need not be of the same size.