  A decomposition of the energy and helicity fluxes in a turbulent hydrodynamic
flow is proposed. The decomposition is based on the projection of the flow to a
helical basis that allows to investigate separately the role of interactions
among modes of different helicity. The proposed formalism is then applied in
large scale numerical simulations of a non-helical and a helical flow, where
the decomposed fluxes are explicitly calculated. It is shown that the total
energy flux can be split in to three fluxes that independently remain constant
in the inertial range. One of these fluxes that corresponds to the interactions
of fields with the same helicity is negative implying the presence of an
inverse cascade that is `hidden' inside the forward cascade. Similar to the
energy flux the helicity flux is also shown that it can be decomposed to two
fluxes that remain constant in the inertial range. Implications of these
results as well possible new directions for investigations are discussed.
