  An attempt is made to supplement Carter's partial investigation of the global
structure of Kerr-Newman spacetime on the symmetry axis. Namely, the global
structure of \theta = const. timelike submanifolds of Kerr-Newman metric
starting from the symmetry axis all the way down to the equatorial plane are
studied by introducing a new time coordinate slightly different from the usual
Boyer-Lindquist time coordinate. It turns out that the maximal anaytic
extension of \theta = \theta_0 (0 \leq \theta_0 < \pi/2) submanifolds is the
same as that of the symmetry axis first studied by Carter whereas \theta =
\pi/2 equatorial plane has the topology identical to that of the
Reissner-Nordstrom spacetime. General applicability of this method to
Kerr-Newman-type black hole solutions in other gravity theories is discussed as
well.
