Given adjacent subanalytic strata $(X,Y)$ in ${\mathbf{R}}^n$ verifying Kuo’s ratio test $\left(r\right)$ (resp. Verdier’s $\left(w\right)$-regularity) we find an open dense subset of the codimension $k$$C^1$ submanifolds $W$ (wings) containing $Y$ such that $(X\cap W,Y)$ is generically Whitney $\left(b^{\pi }\right)$-regular is exactly one more than the dimension...