  In this paper we investigate whether the features of the non-equilibrium
cascade, which have been identified in recent studies using high-fidelity
tools, can be captured in the case of the classical dissipation scaling by
turbulence closures based on the statistical description of freely decaying
isotropic turbulence. Numerical results obtained using the EDQNM model over a
very large range of Reynolds numbers (from $Re_{\lambda}=50$ up to
$Re_{\lambda}=10^6$) are analyzed to perform an extensive investigation of the
scaling region identified as inertial range in Kolmogorov's theory. It is
observed that EDQNM results are in agreement with the results of Lundgren's
matched asymptotic expansion approach to the Karman-Howarth equation. Both
predict that the Kolmogorov inertial range equilibrium is never obtained
irrespective of Reynolds number. Equilibrium is reached in the vicinity of the
Taylor length $\lambda$ (which depends on viscosity) as Reynolds number tends
to infinity and there is a gradual departure from equilibrium as the length
scale moves away from $\lambda$, in particular towards scales larger than
$\lambda$ all the way to the integral length-scale.
