The Blohm & Voss Bv 138 Seedrache (Sea Dragon) — nicknamed the Fliegender Holzschuh (Flying Clog) — was Germany's principal long-range maritime reconnaissance flying boat of World War II. Distinguished by its twin-boom configuration, gull-wing layout, and three Junkers Jumo 205D diesel engines, the Bv 138 conducted extended patrols across the North Atlantic, Arctic, and Baltic theatres, often refueling from U-boats to sustain 18-hour endurance missions. This structured collection assembles 14 original technical documents covering the Bv 138 B-1 and C-1 production variants, their armament systems, and associated recognition and photographic reference materials.

Definitive Collection with Free Lifetime Updates: This is a living collection that we continuously expand and refine. As we acquire additional Bv 138 documentation, aerodynamic studies, or variant-specific materials, we update this collection and provide free lifetime updates to all purchasers. Your one-time purchase guarantees access to all future additions and improvements to this collection.

Historical Note

Design work began at Hamburger Flugzeugbau (later Blohm & Voss) in the mid-1930s under the designation Ha 138. Early prototypes suffered severe instability and inadequate lift, forcing a comprehensive redesign of the wing, hull, and tail surfaces. The definitive Bv 138C-1 introduced an extended hull with a characteristic hydrodynamic "beak" at the stern, increased wing dihedral, and structural reinforcement to withstand open-ocean operations in heavy seas. The high-mounted central engine with a four-bladed propeller and the gull-wing configuration were retained from the redesign as key stability solutions. A specialized minesweeping variant — the Bv 138 MS "Mausi" — was developed with an electromagnetic degaussing ring encircling the hull and wings to detonate magnetic mines. Some aircraft were also equipped with FuG 200 Hohentwiel maritime search radar and Walter RATO rocket boosters for heavy-load departures. Approximately 279 aircraft were built across all variants, serving primarily with Küstenfliegergruppen until 1944–45.

For a detailed historical overview, visit our dedicated article: Blohm & Voss Bv 138 Seedrache — Online Aviation Library Blog.

Manuals Included in This Collection

Variant B & C — 7 Documents

Bv 138 B-C Aircraft Handbook

• Bv 138 B-1, C-1 — Aircraft Handbook 1941, Flugzeug-Handbuch (German Language)
• Bv 138 B-1, C-1 — Aircraft Handbook 1944, Flugzeug-Handbuch (German Language)

Bv 138 B-C Armament

• Bv 138 B-1, C-1 — Firearms Installation Operating Instructions, Bedienungsvorschrift Wa Schußwaffenanlage (German Language)

Bv 138 B-C Flight Manual

• Bv 138 B-1, C-1 — Flight Operating Instructions Manual, Bedienungsvorschrift Fl (German Language)

Bv 138 B-C Operating Instructions

• Bv 138 B-1 — Short Operating Manual, Kurzbetriebsanleitung (German Language)
• Bv 138 B-1, C-1 — Short Operating Manual, Kurzbetriebsanleitung (German Language)

Bv 138 B-C Slides, Photos and Brochures

• Bv 138 B-1, C-1 — Aircraft Instructional Image Series, Lehrbildreihe (German Language)

Non-Variant Manuals — 7 Documents

Bv 138 Armament

• MG 131 Heavy Machine Gun Weapon Manual, MG 131 Waffen-Handbuch (German Language)
• MG 151 Aircraft Cannon Weapon Manual, MG 151 Waffen-Handbuch (German Language)
• ETC 50/VIII b and d Bomb Release Device Description Manual, ETC 50/VIII b LDv 167 (German Language)

Bv 138 Slides, Photos and Brochures

• Bv 138 — Series of Photographs, Bilddokumentation (German Language)
• Bv 138 — Aircraft Recognition Charts, Flugzeug-Erkennungsdienst (German Language)
• Bv 138 — Technical Drawing Sheet, Zeichnungen (German Language)

The collection spans aircraft handbooks, flight and operating instructions, armament manuals for the MG 131, MG 151, and ETC 50 bomb release system, plus photographic, recognition, and technical drawing references — covering the full operational and maintenance documentation scope of the Bv 138 B and C series.

Engineering Norms and Standards

Documentation reflects Luftwaffe technical standards and Blohm & Voss engineering practices of the 1938–1945 period. Materials reference RLM (Reichsluftfahrtministerium) structural and airworthiness specifications, Junkers Motorenwerke engineering norms for the Jumo 205D opposed-piston diesel series (880 hp per engine, glycol "hot cooling"), and Kriegsmarine operational requirements for extended maritime patrol endurance. Performance parameters documented include maximum speed 285 km/h at sea level, cruising speed 250 km/h at 1,000 m, maximum range 4,300 km / 18 hours, service ceiling 5,000 m, and maximum takeoff weight 17,650 kg. Structural reports address twin-boom flying boat design under open-ocean operational loads, hull hydrodynamics, water takeoff and landing stresses, and RATO system integration.

Format and Delivery

• Instant digital download — PDF format, print-friendly
• Organized folder hierarchy by document type and variant
• Compatible with all standard PDF readers on desktop, tablet, and mobile
• Curated and indexed for research and restoration reference

This collection is provided for historical research and archival reference only. These are wartime-era technical documents; consult qualified aviation professionals for any airworthiness or restoration decisions. Trade names and designations are the property of their respective owners. This digital compilation, structure, indexing and presentation are © Sicuro Publishing.