  The detailed investigation of the single pion production reactions $pp\to
pn\pi^{+}$ and $pp\to pp\pi^{o}$ at the incident proton momentum 1628 MeV/c has
been carried out. The data are analyzed in the framework of the event-by-event
maximum likelihood method together with the $pp\to pp\pi^{0}$ data measured
earlier in the energy region below 1 GeV. At 1628 MeV/c the largest
contributions stem from the $^{3}P_{2}$, $^{3}P_{1}$, $^{3}P_{0}$, $^{1}D_{2}$
and $^{3}F_{2}$ initial partial waves.
