  We present the analysis of isovector axial vector nucleon form factors on a
set of $N_f=2+1$ CLS ensembles with $\mathcal O(a)$-improved Wilson fermions
and L\"uscher-Weisz gauge action. The set of ensembles covers a pion mass range
of $130-353\,$MeV with lattice spacings between $0.05\,$fm and $0.09\,$fm. In
particular, the set includes a $L/a=96$ ensemble at the physical pion mass. For
the purpose of the form factor extraction, we employ both the summed operator
insertion method (summation method) and explicit two-state fits in order to
account for excited-state contributions to the nucleon correlation functions.
To describe the $Q^{2}$-behavior of the form factors, we perform $z$-expansion
fits. Finally, we present HBChPT-inspired chiral and continuum extrapolations
of the axial charge and radius.
