Original photo caption: "Martin BM-1 dive bomber of 1930, from which the Germans developed their famous dive-bombing techniques of WW II."
08/31/2006. Remarks by Jack McKillop: "This aircraft crashed on November 6, 1932 during flight tests before it had been accepted by the US Navy. Serial re-used on the second production BM-1 which had strengthened structure. Only the first BM-1 had wheel pants and an engine cowling so this one has to be Number 1."