05/31/2011. Remarks by Johan Visschedijk: "The first prototype BV 138 V1 (D-ARAK c/n 114) first flew July 15, 1937, the second (D-AMOR) a few months later having a number of hull changes and an increase in the vertical tail projecting below the tail boom. After considerable flight testing discovering inadequate stability, poor hydrodynamics and weak hull construction the company decided to abondon work on the third prototype.

A complete redesign retained only the basic configuration and had a new and much larger hull. The first of six pre-production aircraft, BV 138 A-01 (D-ADJE c/n 148) flew for the first time in February 1939, it was later coded "TW+BC".