All that exists of the unbuilt F.XV design are two drawings and two sheets of technical description.

The drawings, dated 29 April and 6 May 1931, both show a large three-engined machine equipped with Armstrong Siddeley Leopard radials. According to their manufacturer, the engines each gave 800 hp, which was quite powerful for those days.

From a remark in the technical description it is clear that Fokker had no doubts about the engines giving their full rated power. Despite the impressive power however, the aircraft allowed space for only twelve passengers. In the earlier-dated drawing the design was given the designation of F.XVa although undoubtedly there must have been an F.XV.

This initial version had a very protrusive cockpit. On the second drawing, the cockpit was positioned further aft to provide more cargo space in the fuselage nose, as was done with the F.IX. The drawing identified the design as the F.XVb.

As a result of placing the cockpit further aft, the pilots of the F.XVb were threatened with being located exactly between the propellers of the outer engines. This arrangement was not without its dangers as there was the possibility of ice being thrown off by the props, penetrating the fuselage walls and injuring the pilots.

Another disadvantage of this configuration would have been excessive noise in the cockpit because of the close proximity to the propeller tips.

The mounting of the engine nacelles on the F.XVb was therefore slightly modified so that the plane of rotation of the propellers was moved ahead of the cockpit.