Nakajima was the main force behind the entire "Project Z." Initially, both the Army and Navy rebuffed Chikuhei Nakajima's ideas. Thus, on their own, Nakajima started researching and planning such a large bomber under the "Project Z" name. Later, Chikuhei pitched the plan again to the Army and Navy and this time they listened. Of course, both services had to throw in their own designs. Keep in mind that the Army and Navy had their own engineers and developers, independent of the aircraft companies. One example was the Army's Kogiken series of aircraft designs, created "in-house" but invited outside aircraft makers to tender their own concepts. At any rate, the Fugaku project never had its own shi number and I've not seen Mitsubishi nor Kawasaki mentioned in any works on the bomber that I've read.
Kawanishi was asked by the Gunjushō (Ministry of Munitions) to design a strategic bomber since the Gunjushō felt the Fugaku would fail. Kawanishi's design was the TB which, ultimately, would get canned.
I've never come across the Fuguku or "Project Z" being referred to as a 18-shi bomber. The only known 18-shi bomber was the Nakajima G8N1. All of the other 18-shi specs were for fighters and one recon plane.
As a note, you may see G10N and G10N1 as the designation for the Nakajima Fugaku but there is no evidence to support their use whatsoever.
Cheers,
Ed
T-50 said:
was Mitsubishi also involved in the Zprogram also known as 18 shi programma?
If they were have someone some info or pics of that aircraft?