For a long time Jan Nieuwenburg and Ab Steenbergen were members of the 'guild' of technical representatives for Fokker. The function had quite its change of titles: Service Engineer, Technical Representative, Area Representative. But the mission was always the same: Make sure that every proud owner of a new Fokker plane - no matter where in the world - learns how to handle the plane, without bothering the plant too much.
 

Both Fokker and the KLM considered the F.VII's only as prototypes. Hardly a month passed or, as a matter of experimentation, another engine was fitted or another stabiliser tried out. Even if Mr Plesman (CEO KLM - transl.) not really appreciated all this, KLM and Fokker had only one goal in mind, the construction of as perfect a plane as possible.