The anisotropy emission of the Ll X-ray line from heavy atoms (54<or=Z₂<or=92) has been investigated experimentally for ion impact (1<or=Z₁<or=79) in the energy range 0.15 to 10 MeV amu^-1. In the case of single ionisation, the collisionally induced alignment of the L₃ subshell can be derived. The data for H and He projectiles are reasonably well described by direct Coulomb ionisation theories. With increasing Z₁, the measured anisotropy becomes considerably smaller than for H impact. No pronounced dependence on the projectile nuclear charge is found although for different projectiles different ionisation mechanisms (direct ionisation, promotion of molecular orbitals) dominate.