Hamburger Flugzeugbau GmbH formed 4 July 1933 as subsidiary of Blohm und Voss shipyard. Designer Reinhold Mewes produced Ha 135 biplane trainer; his successor Richard Vogt produced Ha 136 advanced trainer, 137 dive-bomber, 138 3-engined flying-boat, 139 4-engined seaplane, 140 twin-engined torpedo seaplane, 141 asymmetric observation aircraft and 142 4-engined transport. Ha 222 6-engined transport flying-boat was being developed when in September 1937 company was renamed Blohm und Voss, subsequent aircraft receiving BV designations.