The Blohm & Voss BV-138 was a long-range recognaissance flying boat. The configuration was of a central boat with twin tail-booms. The first prototype was manufactured in March 1935. The prototypes was not stable and has structural problems in rough seas. It was decided to redesign the aircraft, and the first aircraft flew for the first time in February 1939. The first order was for 25 pieces, some of which were used during the occupation of Denmark and Norway. Additional armament was later fitted, bringing the version number to BV-138 B-1.

The aircraft were deployed in the North Sea and in the Atlantic during 1940-1941. An improved version, the BV-138 C-1 entered production during March 1941. This differed slightly externally and was powered by three 12-cylinder Junkers Jumo 205D diesel engines.

Some BC-138s were converted for mine-detection and designated the BV-138 MS. They were equiped with a large magnetically sensitive ring, and lacked armament.

A single BV-138 exists in a Museum in Helsingør in Denmark.

Specifications:

Length: 19.85 m
Wingspan: 26.95 m
Height: 5.90 m
Powerplant: 3 x Junkers Jumo 205D or 3 x Junkers Jumo 250 C
Maximum speed: 275 km/h
Range: 4,500 km
Service ceiling: 5,000 m
Armament: 2 x MG 151 20mm machine cannons, 1 x MG 131 13mm machine gun, 3 x 50 kg bombs.