During 1925, in addition to the first design sketches for the Fokker F.VIII plus development of the Fokker F.IX, drawings were prepared of an enlarged version of the Fokker F.VIIa-3m designated the F.X.
This aircraft should have seated a maximum of ten passengers, two more than the F.VIIa-3m - and as a design, the F.X was put down on paper even earlier than the F.VIIa-3m.
It is intriguing that the two drawings still existing from this design show different engine locations.
The one drawing where the design is identified as the F.X, shows the outboard engines suspended under the wing, while on the other drawing of the aircraft (under the designation FXa), they are situated on the wing leading edge.
The dilemna once more arose of the engine installation, something that also played a part in the development of the F.VIIa-3m. With the F.X there was more time in which to research the method of support and build it into the wing.
The F.X was undoubtedly intended as an alternative to the F.VIIa, or at least was an effort to offer the market a larger aircraft while making as much use as possible of existing parts.