A feedback arc set in a directed graph D is a set S of arcs in D such that D\S is acyclic. The problem of determining a feedback arc set with least number of arcs is NP - complete for a general digraph. We define the strong feedback arc number βs(G) for various orientations of an undirected graph G. The strong feedback arc problem of an undirected graph is to find a strong feedback arc set S of G(O) for some strongly oriented O(G) such that |S| = βs(G). In this paper our focus is on interconnection networks with βs = 1. © 2009 IEEE.