  Building upon a previous analysis of P V wind lines in LMC O stars, we
analyze the P V wind lines in a sample of Galactic O stars which have empirical
mass loss rates determined from either their radio fluxes or H alpha profiles.
Since the wind analysis provides a measure of \dot{M}q where q is the
ionization fraction of the ion, we determine q(P V) observationally. In spite
of model predictions that q should be about 1 for mid-O stars, we find q(P V)
is less than 0.15 throughout the O stars. We discuss the origin of this
discrepancy.
