  There is still significant debate about the symmetry of the order parameter
in the heavy-fermion superconductor UPd$_{2}$Al$_{3}$, with proposals for
cos(k3), cos(2k3), sin(k3),and exp(i\phi) sin(k3). Here we analyze the
tunneling spectroscopy of this compound and demonstrate that the experimental
results by Jourdan et al are inconsistent with the last two order parameters,
which are expected to show zero-bias conductance peaks. We propose a definitive
tunneling experiment to distinguish between the first two order parameters.
