Blohm & Voss BV 138

Blohm & Voss BV 138
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Name	Blohm & Voss BV 138
Caption	BV 138 maritime patrol flying boat
Type	Maritime patrol aircraft
Manufacturer	Blohm & Voss
First flight	1937
Introduced	1940
Retired	1950s
Primary user	Luftwaffe
Produced	200+

Blohm & Voss BV 138 was a German three-engined maritime patrol flying boat developed in the late 1930s for long-range reconnaissance and anti-shipping warfare. Designed and produced by Blohm & Voss, it served with the Luftwaffe and Kriegsmarine maritime units during World War II, operating over the Atlantic Ocean, Norwegian Sea, and Arctic convoy routes. The type combined innovations in hull design, three-engine reliability, and defensive armament to meet requirements set by the Reichsluftfahrtministerium and maritime planners.

Design and development

The BV 138 emerged from a competition influenced by requirements from the Reichsluftfahrtministerium, Ernst Udet, and naval authorities in the late 1930s, responding to Junkers Ju 52 adaptations and lessons from the Spanish Civil War and Spanish Republican Air Force operations. Blohm & Voss design teams led by Hans Amtmann and engineers experienced with Hamburg shipbuilding drew on research from the Kaiserliche Werft tradition and earlier flying boats such as the Short Sunderland and Consolidated PBY Catalina. Prototype work integrated hydrodynamic testing at the Lloyd's Register facilities and wind tunnel data from Aerodynamische Versuchsanstalt Braunschweig. Initial flight trials referenced procedures from the Deutsche Versuchsanstalt für Luftfahrt and evaluation by units attached to Fliegerführer Atlantik.

Development incorporated feedback from Erprobungskommando 2 and operational commanders including ties to Adolf Galland's staff and coordination with Kriegsmarine signals units. Production planning involved subcontracting across firms like Fokker, Heinkel, and Dornier affiliates, with final assembly in Blohm & Voss shipyards influenced by practices used on Bismarck (1939) and other naval projects.

Technical description

The BV 138 featured a characteristic hull derived from shipbuilding techniques, a glazed nose cockpit, and a high-mounted gull wing with three engines mounted in nacelles. Powerplants included variants of the BMW 132 and Bramo 323 radial engines, installation practices similar to those used on the Heinkel He 111 and Dornier Do 24. The hull incorporated steps and sponsons informed by research at Küstenschutz coastal test centers and compared with hulls of the Savoia-Marchetti and Martin P5M Marlin.

Crew accommodation and mission equipment included navigation tables compatible with Lorenz radio compass use, FuG 200 Hohentwiel radar housings in later models, and bomb bay adaptations for depth charges and torpedoes similar to loadouts used by Fairey Swordfish squadrons. Defensive armament evolved with dorsal turrets and machine gun mounts using MG 15 and MG 81 weapons linked to ammunition stowage practices from Flak logistics. Structural design used mixed steel and duralumin alloys following material regimes enforced by the Reichswerke Hermann Göring and procurement from firms like Krupp.

Operational history

Operational deployment began with maritime reconnaissance missions supporting Operation Weserübung and patrols over the North Sea and Norwegian campaign. BV 138 units provided convoy escort reconnaissance during the Battle of the Atlantic, cooperating with U-boat wolfpacks coordinated by Befehlshaber der U-Boote command and integrating signals intelligence from B-Dienst intercepts. Crews operated from seaplane bases such as Rødøy, Kirkenes, Tórshavn, and forward bases in France and Norway, often under coordination with Luftflotte 5 and Luftflotte 3.

The type saw action in Arctic operations supporting the Siege of Murmansk supply interdiction and reconnaissance for naval sorties involving Scharnhorst and Tirpitz. BV 138s were also used for search and rescue missions in cooperation with Seenotdienst units and for clandestine transport tasks similar to those performed by Arado Ar 196 coastal reconnaissance aircraft. Losses occurred due to anti-aircraft fire from Royal Navy escorts, interception by Royal Air Force fighters such as the Supermarine Spitfire and Hawker Hurricane, and harsh weather in polar operations; surviving crews were repatriated via facilities managed by the Deutsche Luftwaffe.

Variants

Several production and prototype variants adapted the airframe and systems, paralleling development patterns seen in types like the Heinkel He 115 and Dornier Do 24. Early prototypes tested different engines including BMW 132 and Junkers Jumo configurations. Production models included armed reconnaissance, radio-equipped meteorological reconnaissance for units like Wettererkundungsstaffel, and specialized versions fitted with FuG 200 radar or long-range fuel tanks used in operations similar to those flown by Blohm & Voss BV 222. Field modifications mirrored upgrades applied to Focke-Wulf Fw 200 Condor units, including reinforced hulls and additional defensive armament.

Operators and deployment

Primary operators were Luftwaffe maritime reconnaissance Gruppen and Kriegsmarine liaison units; units were attached to commands such as Fliegerführer Atlantik, Kommando der Seeflieger, and various Seefernaufklärungsstaffeln. Allied forces including the Royal Norwegian Air Force captured or evaluated examples post-surrender; captured airframes underwent inspection by personnel from Royal Air Force and United States Army Air Forces evaluation groups like Luftwaffe Test Division analogues. Deployment extended across bases in Germany, Norway, France, and the Iceland-Faroes area, supporting naval operations in theaters including the Mediterranean to a lesser extent.

Surviving aircraft and replicas

No complete original BV 138 is known to survive in museum condition; remnants and components were inspected by teams from institutions such as the Imperial War Museum, Deutsches Technikmuseum Berlin, and Norwegian Aviation Museum. Replicas and full-scale restorations have been proposed by preservation groups associated with Classic Flight and maritime heritage organizations that document types like the Short Sunderland. Wreck sites in Norwegian fjords and Arctic waters remain of interest to researchers from universities such as University of Oslo and maritime archaeologists affiliated with Sverdrup Research. Memorials to crews appear near former bases like Kirkenes and in exhibits covering the Battle of the Atlantic.

Category:Blohm & Voss aircraft