Her fifth patrol, in June 1940 was one of her most successful, making full use of the situation in Europe following the Fall of France. U-48 was commanded by Hans Rudolf Rösing, as Herbert Schultze was hospitalised with a kidney and stomach complaint.
In June 1940, during her fifth patrol, U-48 achieved great success, taking advantage of the aftermath of France's fall.  The submarine was under the command of Hans Rudolf Rösing while Herbert Schultze was ill with a kidney and stomach problem.