In 1936, Hawks had approached Howell W. "Pete" Miller, chief engineer for the Granville Brothers and responsible for their famous Gee Bee racers, to create a racing aircraft from his own design, the Hawks Miller HM-1. Miller rebuild the aircraft in 1938 as a two-seater for military purposes. The aircraft was first renamed the Miller HM-2, but when company was reorganized as the Miller Aircraft Co., it was called the MAC-1 and Military Aircraft HM-1.
The Usaac was interested in the monoplane and after tests a contract was signed for six aircraft, used as a fighter-bomber. They were send to the 17th PS. But after several training missions the Usaac wasn’t satisfied and cancelled the contract for more.
The USN, busy to obtain monoplanes for fighter and bomber duties, was also interested and Miller and Hawks upgraded the HM-1 with a different canopy and an all metal fuselage, called the MH-1A.
The MH-1A fighter-bomber was ment to use on board carriers, but the USN was also testing the SBD from Douglas as a replacement for the BT-1. So the first MH-1A’s were delivered to the Marines. Before the SBD dauntless was delivered several MH-1A’s were also delivered to squadrons on board the carriers, and there was in 1939 an MH-1B torpedo-version.
Here are the examples:
regards
Lauhof