However, the combat technique of using concentrated upward fire and mixed incendiary bullets had been proven by Leefe Robinson, and more successes quickly followed. On 23 September 1916, Frederick Sowrey, also of 39 Squadron, shot down the Zeppelin "L.32". On the night of 1/2 October 1916, 2nd Lieutenant W. L. Tempest of 39 Squadron, flying a B.E.2c, spotted the Zeppelin "L.31", illuminated by searchlights over southwest London, and shot it down with the loss of the entire airship crew. In all, five more German airships were destroyed by Home Defence B.E.2c interceptors between October and December 1916.