  We calculate the density of states $N$ and the the thermal conductivity
$\kappa $ in layered superconductors for rotating in-plane magnetic field by
using approximate analytical expressions for Abrikosov's vortex lattice state.
For a gap with d$_{xy} $- orbital symmetry we find that the differences $\Delta
N$ and $\Delta\kappa$ between field directions parallel to the antinodes and
parallel to the nodes of the gap are positive for lower fields and change sign
for higher fields near $H_{c2} $. For increasing impurity scattering, $\Delta
N$ and $\Delta\kappa$ decrease due to a broadening of certain peaks in the
angle-resolved density of states. The frequency dependencies of the amplitudes
$\Delta N$ and $\Delta\kappa$ exhibit similar crossover behavior at low
frequencies which give rise to a sign change of $\Delta\kappa$ at low $T/T_c $.
We conclude that variations of the specific heat and thermal conductivity can
be observed only in the clean and low temperature limits.
