Published by Kagero in 2018, 20 pages. Large A4 size Booklet with loose leaf fold-outs (N6933)
The main booklet is illustrated throughout with detailed line drawings showing plans of the vehicle, and also includes 4 pages colour drawings showing individual profiles of tanks with different designs and camoflauge. There are also 2 large loose leaf fold outs with further detailed line diagrams and drawings. All captions and text is in both English and Polish.
From the introduction: Emergence of the Ki-S4 was spurred by the availability of a new 18 cylinder Ha-4S twin radial engine manufactured by Nakajima. The first prototype of the new fighter was ready on March 20, 1943, with the first flight taking place in April. In June 1943, as the flight test program continued, two more prototypes were completed.
The second series of 42 "additional prototypes" was built between March and June 1944. The full scale production of the Ki-S4's first and basic version Ki-S4 Ko was launched in Ota in April 1944 when the production and flight testing of prototype machines was still ongoing. All Ki-S4 Ko fighters featured offensive armament consisting of two fuselage-mounted Ho-103 12.7 mm guns and two Ho-5 20 mm cannons installed in the wings. Early-production examples were still powered by the Ha-45-11 engines, but those were soon replaced by the Ha-4S-12 engines developing lS25 hp. Later on a more advanced version of the engine was introduced - Ha-45-21 - which featured a more efficient supercharger and developed 1990 hp.
In March 1945 Gijutsubu approved the production of the Ki-S4 Otsu, armed with four Ho-5 cannons - two mounted in the fuselage and two in the wings. Two prototypes of the heavily armed Ki-84 Hei and Ki-84 Tei may have also been built, but the aircraft never went into production. The Ki-S4 Hei was to mount two Ho-5 cannons in the fuselage and two Ho-155-11 30mm cannons in the wings. The Teivariant was to be armed with an upwardfiring Ho-5 cannon mounted behind the cockpit at a 45 degree angle, in addition to the weapons fit identical to the Otsu version.
In total, 331S production examples of the Ki-S4 were manufactured before the war's end, mainly the Ko versions. Including the three prototypes and 101 additional prototypes, the total production stands at 3422 examples.