The Blohm & Voss Ha 139 was a German all-metal inverted gull wing floatplane. With its four engines it was at the time one of the largest float-equipped seaplanes that had been built. The inboard engines were mounted at the joint between the inboard anhedral and outboard dihedral wing sections, above the pylon-mounted floats. Further development of the Ha 139 led to the land-based version Blohm & Voss BV 142 which had its first flight in October 1938. The aircraft were flown by Deutsche Luft Hansa on transatlantic routes between 1937 and 1939, predominately between Bathurst, The Gambia and Natal, Brazil. Catapult-launched from an aircraft tender they were able to transport 500 kg of mail over a distance of up to 5,000 km. On the outbreak of World War II, the planes were transferred to the Luftwaffe and used for transport, reconnaissance and minesweeping work over the Baltic Sea. They were not particularly suited for military use. Variants Projekt 15 Catapult launched floatplane mail-carrier design for Deutsche Lufthansa (DLH), became the Ha 139. Projekt 20 A reconnaissance-bomber derivative of Projekt 15 submitted to the Reichsluftfahrtministerium (RLM) (German air Ministry) but generating little interest. Ha 139 V1 Named Nordwind — First of two baseline prototypes Ha 139 V2 Named Nordmeer — Second of two baseline prototypes Ha 139 V3 Named Nordstern — Third prototype with longer wingspan, increased wing area and modified engine mounts. Ha 139B The Ha 139 V3 re-designated when in service with DLH. Ha 139B/Umbau After service with DLH, the Ha 139B was modified as the Ha 139B/Umbau with an extended glazed nose accommodating a navigator and a spherical Ikaria mount for a machine-gun. Further machine guns were mounted in the cockpit roof hatch and in lateral mountings on either side of the rear fuselage. Ha 139B/MS The Ha 139B/Umbau was later modified into a minesweeping (Minensuch) aircraft fitted with a large magnetic sensing loop strung between the nose, floats, wing-tips, and tail unit.
