We give necessary and sufficient conditions for a given element to be a member of the second order tangent set $T»_{K}(f,v)$ to the positive cone $K$ in $L^{\infty}¸.$ Since, in general $T»_{K}(f,v)$ may be empty we give conditions on functions $f¸, v$ which ensure that the second tangent set is a cone. As an application of the results obtained we give a characterization of the elements of the first and second tangent set to the set $B={u\in W^{1,\infty}(Ømega)¸ |¸|\nabla u|^{2}\leq 1}¸.$