"unused" IJN designations?

[Spindash64]

I'm struggling to find the words to explain, so I'll just jump into it: there's a J2M, there were supposedly plans for a J4M, and there was a J8M "Shusui" prototype. So, whatever happened to J3M and J5-7M? I can't find anything suggesting the existence of these as even ideas in someone's head. I don't JUST mean it with the Mitsubishi land-based fighters, but they paint a clear picture of what I'm asking, so

 

[Shinpachi]

They are -

J1N 13-shi twin-engined
J2M Raiden
J3K 17-shi land-based
J4M Senden
J5N Tenrai
J6K Jinpu
J7W Shinden
J8M Shusui

Source:

日本製航空機の一覧 - Wikipedia

ja.wikipedia.org

 

[Wurger]

 

[Spindash64]

Ah. I had thought that the IJN system worked more like the USN system, where A6M2 would mean the 6th carrier fighter proposal by Mitsubishi specifically.

 

[pb43]

Ah. I had thought that the IJN system worked more like the USN system, where A6M2 would mean the 6th carrier fighter proposal by Mitsubishi specifically.

Unusually, the J series numbers progressed regardless of manufacturer

go to :

Imperial Japanese Navy Aircraft

and

Japanese military aircraft designation systems - Wikipedia

en.wikipedia.org

 

[Wurger]