AZ 1/72 D4Y3 Suisei

The origins of the D4Y can be traced back to 1938, when the Imperial Japanese Navy Aviation Bureau (Kaigun Kōkū Hombu) issued requirements for a carrier-based dive bomber to replace the Aichi D3A. The emerging aircraft would be a single-engine, all-metal, low-wing monoplane, with a wide-track retractable undercarriage and wing-mounted dive brakes.

Though reported that its design may have been influenced by the Heinkel He 118 (itself a development of the He 70, losing out to the Junkers Ju 87 Stuka in the 1930s and never ordered by the Luftwaffe), as the Japanese Navy having acquired two He 118 examples from Germany in early 1938, the two aircraft had actually little in common.

The Suisei had a crew of two, a pilot and a navigator/radio operator/gunner, seated under a long, glazed canopy which provided good all-round visibility. Power was provided by the Aichi Atsuta liquid-cooled inverted V12 engine, a licensed copy of the Daimler-Benz DB 601, rated at 895 kW (1,200 hp), with the radiator housed behind and below the three-blade propeller.

The aircraft had a slim fuselage that enabled it to reach high speeds in both horizontal flight and in dives whereas, despite its high wing loading, it exhibited great maneuverability, having superior flight characteristics to contemporary dive bombers such as the Curtiss SB2C Helldiver.

This good performance, apart from the solid design, was also attributed to the minimized weight by not fitting the D4Y with self-sealing fuel tanks or armor, in order to conform with the Japanese Navy's (not particularly well-aimed) requirement for long range, which made the type extremely vulnerable and tended to catch fire when hit.

Armament consisted of two machine guns in the nose and one in the rear of the cockpit. Bombs were fitted under the wings and in an internal fuselage bomb bay. Usually one 500 kg (1,100 lb) bomb was carried, but there were reports that the D4Y sometimes carried two 250 kg (550 lb) bombs.

The first (of five) prototypes made its maiden flight in December 1940, with the type entering service roughly a year later. Upon the first flights of the prototype, serious problems with flutter were encountered, forcing the IJN not using the type as a dive bomber (as flutter would be catastrophic there), but as a reconnaissance plane, where its long range and high speed were favorable and the missions themselves were not imposing serious stresses to the airframe.

Flutter problems were solved by mid-1943, at about the time where the increasing losses of the D3A dictated the D4Y's operational entry as a dive bomber. At about the same period, (and justifying the initial design critiques of the inline engine), the unreliability of the Atsuta power plant led to the fitting of the proven Mitsubishi MK8P Kinsei 62, 14-cylinder two-row radial. The new engine offered improved ceiling and rate of climb, but its higher fuel consumption resulted in reduced range and cruising speed. Also, its width obstructed the forward and downward view of the pilot, hampering carrier operations.

Lacking armor and self-sealing fuel tanks, the Suiseis did not fare well against Allied fighters. They did, however, cause considerable damage to ships, including the carrier USS Franklin which was nearly sunk by an assumed single D4Y and the light carrier USS Princeton which was sunk by a single D4Y.

An interesting version was the D4Y4 Special Strike Bomber, a single-seat kamikaze aircraft, capable of carrying one 800 kg (1,800 lb) bomb partially fitted in the bomb bay. Equipped with three rocket boosters for terminal dive acceleration, this aircraft was an almost ideal kamikaze model, exhibiting a combination of speed (350 mph), range (1,550 mi) and payload, probably not matched by any other Japanese aircraft.

The Judy seems to be a classic example of an otherwise well designed and evolved plane that was hampered by some not well aimed requirements, in this case the choice of absolute endurance over armor plating and fuel tanks self sealing, the lack of which severely compromised its resilience against enemy fire, preventing it to show its full potential. Ultimately, 2,038 of all variants were produced.

This is the initial release radial engined (D4Y3) version of the very nice AZ 1/72 Judy family, which started hitting the shelves in 2012 and with all versions regularly reboxed ever since. By all means very good kits, offering plenty of detail, requiring their usual extra attention during construction due to their high-end limited-run nature.

The specific kit was yet another gift from my good friend @lis, who was kind enough as to include fantastic extra goodies inside (Beaver Corp PE set and various masks). Should you wish to read the full build review, you may do so by visiting my beloved site Modelingmadness:
https://modelingmadness.com/review/axis/j/jnaf/attack/pend4y.htm

Happy Modelling!