  Spacial variation of the orbital part of the order parameter of $^3$He-A in
aerogel is represented as a random walk of the unit vector $\mathbf{l}$ in a
field of random anisotropy produced by the strands of aerogel. For a range of
distances, where variation of $\mathbf{l}$ is small in comparison with its
absolute value correlation function of directions of $\mathbf{l}(\mathbf{r})$
is expressed in terms of the correlation function of the random anisotropy
field. With simplifying assumptions about this correlation function a spatial
dependence of the average variation $\langle\delta\mathbf{l}^2\rangle$ is found
analytically for isotropic and axially anisotropic aerogels. Average
projections of $\mathbf{l}$ on the axes of anisotropy are expressed in terms of
characteristic parameters of the problem. Within the "model of random
cylinders" numerical estimations of characteristic length for disruption of the
long-range order and of the critical anisotropy for restoration of this order
are made and compared with other estimations .
