On the transposed Rao’s flag-transitive plane of order 49

Rao’s flag-transitive plane π of order 49 and π t , the plane obtained by transposing matrices of a representative set of π , has been studied. It is shown that π t is flag-transitive, π t is not isomorphic to π , and π t is obtained from π by replacement of a net of degree 25. Further, (1) the flag-transitive planes associated with 1-spread sets S 2 b and S 2 a in the classified list of translation planes of order 49 enumerated by Mathon et al, are respectively isomorphic to π and π t (2) The flag-transitive planes associated with the 1-spread sets of 0an* in the classified list of translation planes of order 49 enumerated by Charnes et al are isomorphic to π and π t in some order.