  Supernovae (SNe) with photospheric spectra devoid of Hydrogen and Helium
features are generally classified as Type Ic SNe (SNe Ic). However, there is
ongoing debate as to whether Helium can be hidden in the ejecta of SNe Ic (that
is, Helium is present in the ejecta, but produces no obvious features in the
spectra). We present the first application of the fast, 1-D radiative transfer
code TARDIS to a SN Ic, and we investigate the question of how much Helium can
be hidden in the outer layers of the SN Ic ejecta. We generate TARDIS models
for the nearby, well-observed, and extensively modeled SN Ic 1994I, and we
perform a code comparison to a different, well-established Monte Carlo based
radiation transfer code. The code comparison shows that TARDIS produces
consistent synthetic spectra for identical ejecta models of SN1994I. In
addition, we perform a systematic experiment of adding outer He shells of
varying masses to our SN1994I models. We find that an outer He shell of only
$0.05M_{\odot}$ produces strong optical and NIR He spectral features for
SN1994I which are not present in observations, thus indicating that the SN1994I
ejecta is almost fully He deficient compared to the He masses of typical
He-rich SN progenitors. Finally we show that the He I $\lambda$20851 line
pseudo equivalent width of our modeled spectra for SN1994I could be used to
infer the outer He shell mass which suggests that NIR spectral follow-up of SNe
Ic will be critical for addressing the hidden helium question for a statistical
sample of SNe Ic.
