Which aircraft designer was born in Frankfurt am Main and had a model produced by Bayerische Flugzeugwerke?
BFW M.23: The BFW M.23, sometimes known as the Messerschmitt M 23, was a 1920s two-seat sporting aircraft designed by Willy Messerschmitt, and produced by "Bayerische Flugzeugwerke" (BFW). Willy Messerschmitt:  He was born in Frankfurt am Main, the son of Baptist Ferdinand Messerschmitt (1858–1916) and his second wife, Anna Maria née Schaller (1867–1942).
Willy Messerschmitt