Interwar Dutch X-Planes?

[AnticlockwisePropeller]

I discovered the Fokker D.XXIII when it was added as a mod to a flight sim I play a while ago. The unusual design piqued my interest, so of course, I had to add one to my model kit stash! (I got the 1/72 Pegasus kit - a surprisingly nice little model). I noticed the serial number of the prototype D.XXIII was X-4, but didn't think much about it until recently, when I watched a youtube video on the Fokker G.I. It turns out, the prototype G.I had the serial X-2, which begs the question:

 

Was there an X-1 and an X-3? And if so, what were they?

 

I couldn't find much information online, mostly because I didn't really know where to look. So hopefully someone a bit more knowledgeable than me can help! Could X-1 have been the prototype Fokker D.XXI?

 

If all four aircraft did exist, it might be nice to build them all as a little collection!

 

 

 

 

[48-Alone-Is-Great]

Here are X-1, a Fokker C-X, and X-3, a Fokker S-IX aka S-9:

 

 

 

However … these were otherwise unregistered temporary codes for test flights (prototypes and exports), used whenever the number was available, so there are several X-1s, X-2s etc:

 

X-1  Fokker C-X (c/n 5418)

X-1  Fokker F-VIIb-3m (c/n 5249, to Japan)

X-2  Fokker G-1 (c/n 5419, possibly later LVA 366)

X-2  Fokker G-1 (c/n 5557, later LVA 341)

X-2  Fokker G-1 (c/n 5558, for Estlonia)

X-2  Fokker G-1 (c/n 5559, later LVA 342)

X-2  Fokker G-1 (c/n 5560, later LVA 343)

X-2  Fokker F-VIIb-3m (c/n 5250, to Japan)

X-3  Fokker S-IX (c/n 5479, later 996)

X-4  Fokker D-XXIII (c/n 5614, later 998)

X-4  Fokker F-VIIb-3m (c/n 5235, to Japan)

 

In those days Koolhoven used Z and others Y. All these codes and more here:

http://www.hdekker.info/registermap/TEST.htm

 

Btw, X-1 to –36 were also used operationally, from 1937 to 1942 in the NEI, on Dornier Do-24s.

 

Edited March 2, 2022 by 48-Alone-Is-Great

[AnticlockwisePropeller]

@48-Alone-Is-Great

 

Thank you so much! That's such interesting and useful information!