Edwin M. Dyer

All the major nations involved in World War Two had many proposed designs for aircraft, vehicles and ships that never made it off the drawing board or past the prototype stage. Military historians, professional and amateur, have explored many of these and speculated on what might have happened if they had gone into production. This can sometimes get just a little creepy; Nazi Germany and Imperial Japan were the original “Axis of Evil” and expressing interest in potential weapons development in those regimes carries an undercurrent of “well, if only they had built these, they might have won”, with the further undercurrent that this might have been desirable. No, it wasn’t.

That out of the way brings me to Japanese Secret Projects, a two-volume set of proposed Japanese aircraft that never made it to production. Author Edwin Dyer provides a wealth of interesting information for the military history buff, a glossary of Japanese aviation terms, pictures and drawings of the aircraft, descriptions of aircraft bombs and gun systems, the extent of German-Japan technology exchange, and a discussion of the Japanese nuclear weapons program. I’ll touch on a few of the things that interested me with the understanding that these are just selections from more comprehensive books.

America bombers: Like the Germans (see Messerschmitt Me264, Target: America, and Luftwaffe Over America) (and even the Italians), the Japanese had various plans for attacking the continental United States with long-range aircraft; these included the Kawasaki Ki-91, the Nakajima Fugaku (aka “Project Z”), the Hitachi “He-Type” (a license-built He177A), the Kawanishi K-60 (a license-built Me264), the Kawanishi “TB”, the Kawasaki Ki-85, the Mitsubushi Ki-90 (a license-built version of the Ju89), the Nakajima G8N1, and the Nakajima Ki-68 (a bomber version of the Douglas DC-4E; the Japanese had acquired a single copy of the DC-4E in 1939). Of these, only the G8N1 and the Ki-68 made it to a flyable aircraft stage; the rest remained wishful thinking, drawings, or mockups. As an example of the ability to plan things far beyond the capability to execute them, the “Project Z”/Fugaku aircraft stands out. This was supposed to be a six-engine heavy bomber. At various times, the aircraft’s proposed role varied among (1) bombing the Northwest United States from bases in the Kuriles; (2) a “deck-clearing” naval attack aircraft. The bomb bay would be filled with 400 type 97 machine guns, pointing down, and the aircraft would fly over an enemy ship and let fly. This was expected to suppress enemy antiaircraft fire, and conventional dive- and torpedo-bombers would then come in. (3) a similar version, outfitted with 96 20mm cannon. This would be a bomber interceptor, attacking enemy aircraft from above. (4) a long-range transport, carrying 300 troops. Massed aircraft would fly to Washington state, land at Seattle, and unload the soldiers to seize control of the airport. Some of them would march overland to destroy the Boeing factory at Renton; the remainder would hold the airport and refuel the aircraft from captured supplies. Everybody would then get back on board and fly back to Japan. Too much sake, I think.

Specialized Kamikaze aircraft: These came in two flavors – cheap airplanes that would be easy to build in large numbers, and rocket or jet powered aircraft that would be immune to interception. In the former category were the Kokusai Ta-Go, the Nakajima Ki-115, the “Kamikaze Airplane” (a twin engine aircraft reported by Allied observers but apparently imaginary), the Kawasaki Ki-48 and Ki-174 (modifications of a twin-engine light bomber for the Kamikaze role), and the Kawasaki Ki-119 (also to be used as a conventional fighter-bomber but designed to be cheap and easy to build from non-strategic material); in the later were the Kawanishi Baika (pulse jet), the Kugisho MXY7 Oka (rocket), and the “Rammer” (rocket, to be used against B-29s). The problem with the “cheap and easy” aircraft turned out to be that although they might have been easy to build they were difficult to fly; since Kamikaze aircraft were supposed to be flown by novices with minimal training that was a severe handicap. The rocket-powered Oka had a couple of successful attacks; however, it had to be carried into range by a “Betty” bomber, which left the bomber very slow and unmaneuverable. As a result, almost all bombers carrying Okas were lost as well, often before they had a chance to launch their payload. Dyer notes that there was a proposed Oka version powered by a “thermojet”; this used a piston engine to run a compressor that then had fuel injected and ignited (none were ever deployed). One of the mysteries here is why the Japanese didn’t develop the Baika pulse-jet bomb. Pulse jets (the most familiar being the German V-1) are cheap, easy to build, fast, and can operate on almost any fuel; it would seem they would be ideal for suicide aircraft.

Giantism: The Japanese are known for giant robots and giant monsters; at one point they proposed a giant seaplane, the Kawanishi KX-3. This was to weigh 500 tons, and be powered by twelve turboprops and four turbojets. The rational was roughly the same as that for the Hughes H-4 (the “Spruce Goose”); an airplane that could carry cargo across the ocean with fear of interception by enemy submarines and surface vessels. Apparently the KX-3 got to the doodle-on-napkin stage and was dropped; the Japanese were unable to build a successful turboprop (the one attempt blew up on the test stand).

Balloon bombs: This gives more detail on the balloon bombs than I have seen elsewhere. Ironically, one of them had a very minor success – it temporarily shorted out a transformer (the electrical kind, not the car that turns into a robot kind) at a military facility in Hanford, Washington. Not enough to disrupt production any, unfortunately for Nagasaki. I was also interested to find that the British has a sort of “balloon bomb” program (Operation Outward); these carried small incendiary charges and dragged long cables, with the idea that the cables would drape across power transmission lines and short them out. In one case an Operation Outward badly damaged a German power station when a overload switch failed to trigger.

There are a number of other interesting items that I won’t go into much detail on; there were a lot of proposed designs for fighter and bomber aircraft with pusher-puller engines; the Japanese ability to design aircraft to use jet engines far outstripped their ability to actually build jet engines; the Allies expected the Japanese would use a lot more license-built German aircraft than they actually did, to the extent that code names were assigned for imagined Japanese versions of the He112 (Jerry), Bu131 (Cypress), Go244 (Buzzard), Ju87 (Irene), Fw190 (Fred), Ju88 (Janice), Bf109 (Mike), Bf110 (Doc), and He111 (Bess); I was surprised to find that a lot of captured Japanese aircraft were shipped to the USAAF 803rd Special Depot, which is now part of O’Hare International Airport, just down the road from where I grew up.

Illustrations are outstanding, although the reader should be aware that despite apparent detail they are depictions of aircraft that never made it past the drawing board stage. Well indexed with a good bibliography. Certainly fun to speculate with.… (plus d'informations)