Now it was the turn of the BMW Big Boxer R18. And the common ground of VTR Custom and Kellermann in the design language became clearer than ever: aviation. The result of this philosophy is "Iron Annie," an R18 inspired by the 1930s Junkers Ju 52. This aircraft became famous under the nickname "Tante Ju," and the look in the Lufthansa livery of the time was particularly well known. One such aircraft was still in service in the USA until 1984, where it was known as the "Iron Annie".