First flight of the Bv 138 (originally known as the Ha 138) was on 15 July 1937 but production models only entered service until early 1940. The initial Bv 138A model was continually plagued by service difficulties which forced most of them to be converted into transports, fortunately most of these problems were successfully resolved in the Bv 138B and the definitive Bv 138C which formed the bulk of production. A minesweeper variant was also developed, it was designated as the Bv 138MS.

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| Design | Bv 138C-1 |
| Name | - |
| Code Name | - |
| Type | Maritime Patrol |
| Year | 1941 |
| Crew | 6 |
| Speed | 275 km/h |
| Ceiling | 5,700 m |
| Range | 4,023 km |
| Engine | 3 x 656-kW Junkers Jumo 205D |
| Weight Empty | 11,000 kg |
| Weight Max | 15,480 kg |
| Wing Span | 27.00 m |
| Length | 19.85 m |
| Height | 5.90 m |
| Wing Area | ? |
| Armament | 2 x 20-mm 1 x 13-mm |
| Payload | 600 kg |
| Production | 227 |
| Total | 127 |