  We have analysed the axisymmetric and non-axisymmetric modes of a continuum
of vortices in a rotating superfluid. We have investigated how changing the
temperature affects the growth rate of the disturbances. We find that, in the
long axial wavelength limit the condition q=alpha/(1-alpha')=1, where alpha and
alpha' are temperature-dependent mutual friction parameters, is the crossover
between damped and propagating Kelvin waves. Thus at temperatures for which
q>1, perturbations on the vortices are unlikely to cause vortex reconnections
and turbulence. These results are in agreement with the recent discovery of
Finne et al (2003} of an intrinsic condition for the onset of quantum
turbulence in $^3$He-B.
