Blohm & Voss Ha 139

The Blohm & Voss Ha 139 was a four-engined, all-metal, inverted gull wing floatplane, designed and built by the German aircraft manufacturer Blohm & Voss. At the time of the first aircraft's completion, it was one of the largest float-equipped seaplanes to have been built.

Development of the Ha 139 started in 1935 to fulfil a specification issued by the German flag carrier Deutsche Luft Hansa. Built to serve on the airline's long distance routes, it was equipped with four hydraulically-actuated landing flaps, was powered by four Junkers Jumo 205C diesel engines, and was suitable for catapult-assisted takeoffs. The Ha 139A was promptly followed by the Ha 139B, a variant that possessed greater size and weight. Development of the aircraft led to a land-based version, the Blohm & Voss BV 142 and a proposed reconnaissance/bomber variant of the Ha 139 for the Luftwaffe was never realised.

During 1935, the firm, having been satisfied with the progress of the Seedrache, decided to embark on design work for a larger four-engined floatplane. From any early stage of development, the prospective aircraft was intended for civilian use by the German flag carrier Deutsche Luft Hansa; the airline's requirements included the carriage of a payload over a staged route at a cruising speed of . The aircraft was also to possess a durable structure and good handling (such as being able to take off and alight on rough seas) while also being suitable for catapult-assisted takeoffs. This wing, which had a mixed covering made of metal (in the centre) and fabric (on the outer panels), was equipped with four hydraulically-actuated landing flaps. The all-metal single-step floats were attached to the wings via a steel stub that was surrounded by a metal fairing that housed a radiator.

Shortly after testing of the Ha 139 commenced in 1937, Blohm & Voss started work on a land-based derivative the BV 142. This version was to incorporate as much of the design and components of the Ha 139 as possible. While originally intended for civil use, it would ultimately see use by the Luftwaffe during the war.

Operational history

thumb|A Ha 139 on board the catapult ship Friesenland.

During March 1937, Deutsche Luft Hansa received the first aircraft, Ha 139 V1; shortly the airline commenced trials in the North Atlantic between the Azores and New York using V1, V2 and a pair of seaplane depot ships. Their appearance was altered and modifications made to enable them to perform reconnaissance and minesweeping operations. The included the addition of an elongated and extensively glazed nose to accommodate an observer while a degaussing loop was installed around the aircraft and field-generating apparatus was installed within the fuselage.

Introduced to service during the Norwegian campaign, the militarised Ha 139s transported troops and freight, reconnaissance and minesweeping sorties over the Baltic Sea. The Ha 139 did not have a lengthy military service, in large part due to a lack of spare components. Proposals to produce a reconnaissance–bomber variant of the aircraft were formulated but never put into action.

Variants

thumb|Ha 139 Nordstern leaving the Friesenland in 1938.

;Projekt 15

:Catapult launched floatplane mail-carrier design for Deutsche Lufthansa (DLH), became the Ha 139.

|prime units?= met

<!--

General characteristics

-->

|crew= 4–5

|length m= 20.07

|span m= 29.5

|height m= 4.8

|wing area sqm= 130

|empty weight kg= 10,340

|gross weight kg= 19,000

<!--

Powerplant

-->

|eng1 number= 4

|eng1 name= Junkers Jumo 205C

|eng1 type= six-cylinder opposed piston diesel engines

|eng1 kw= 447

|eng1 note= for take-off

|prop blade number= 3

|prop name= variable-pitch metal propellers

<!--

Performance

-->

|max speed kmh= 288

|max speed note= at

|cruise speed kmh= 238

|cruise speed note= (maximum) at

Economical cruise speed:

|ferry range km= 4,600

|ferry range note= at <br />

::: at

|climb rate ms= 2.8

<!--

Armament

-->

|guns= 4 × 7.92 mm (0.312 in) MG 15 machine guns in nose, flight deck roof hatch, and staggered fuselage lateral mountings

Blohm & Voss Ha 139

Operational history

Variants

See also

References

Citations

Bibliography

Further reading

External links