  The Ti:Saphire laser operated within 13800 - 11800 cm$^{-1}$ range was used
to excite the $c^3\Sigma^+$ state of KCs molecule directly from the ground
$X^1\Sigma^+$ state. The laser-induced fluorescence (LIF) spectra of the
$c^3\Sigma^+ \rightarrow a^3\Sigma^+$ transition were recorded with
Fourier-transform spectrometer within 8000 to 10000 cm$^{-1}$ range. Overall
673 rovibronic term values belonging to both $e/f$-components of the
$c^3\Sigma^+(\Omega=1^{\pm})$ state of $^{39}$KCs, covering vibrational levels
from $v$ = 0 to about 45, and rotational levels $J\in [11,149]$ were determined
with the accuracy of about 0.01 cm$^{-1}$; among them 7 values for $^{41}$KCs.
The experimental term values with $v\in [0,22]$ were involved in a direct
point-wise potential reconstruction for the $c^3\Sigma^+(\Omega=1^{\pm})$
state, which takes into account the $\Omega$-doubling effect caused by the
spin-rotational interaction with the nearby $c^3\Sigma^+(\Omega=0^-)$ state.
The analysis and interpretation were facilitated by the fully-relativistic
coupled cluster calculation of the potential energy curves for the $B^1\Pi$,
$c^3\Sigma^+$, and $b^3\Pi$ states, as well as of spin-forbidden $c-X$ and
spin-allowed $c-a$ transition dipole moments; radiative lifetimes and vibronic
branching ratios were calculated. A comparison of relative intensity
distributions measured in vibrational $c-a$ LIF progressions with their
theoretical counterparts unambiguously confirms the vibrational assignment
suggested in [\emph{J. Szczepkovski, et. al.}, JQSRT, \textbf{204}, 133-137
(2018)].
