Aichi S1A1 Denko

The Aichi S1A1 Denko (Bolt of Light) was intended to be the replacement for the Nakajima J1N1-S Gekko, filling the role of a radar-equipped night fighter to combat the American B-29 raids. Development time increased while trying to overcome the shortcomings (insufficient power) of the Navy's requested engines to be used, resulting in no aircraft being completed before the war ended. Both of the S1A1 prototypes were destroyed in separate Allied bombing raids when they were only 70-90% complete.

Aichi S1A Denko

Type: advanced nightfighter

Service: Japanese Navy Air Force (JNAF)

Crew: two

Armament: two fuselage-mounted forward-firing 30mm Type 5 cannons

                   two fuselage-mounted forward-firing 20mm Type 99 cannons

                   two dorsal turret-mounted 20mm Type 99 Model 2 cannons

                   one 551 lb (250 kg) bomb externally

Specifications:

        Length: 49' 6.5" (15.1 m)

        Height: 15' 1.5" (4.61 m)

        Wingspan: 57' 5" (17.5 m)

        Wing area: 505.902 sq. ft (47 sq. m)

        Empty Weight: 16138 lbs (7320 kg)

        Loaded Weight: 22443 lbs (10180 kg)

        Max Weight:25375 lbs (11510 kg)

Propulsion:

        No. of Engines: 2

        Powerplant: Nakajima NK9K-S Homare 22 18-cylinder radial

        Horsepower: 2000 hp each

Performance:

        Normal Range: 1054 st miles (916 naut miles)

        Max Range: 1580 st miles (1373 naut miles)

        Cruise Speed: 276 mph at 13125 ft (240 kt at 4000 m)

        Max Speed: 366 mph  at 26245 ft (318 kt at 8000 m)

        Climb to/in: 29530 ft (9000 m) in 14 min 45 sec

        Ceiling: 39370 ft (12000 m)

Production: No aircraft completed by the end of the war.

Additional color schemes for this aircraft can be found here.

Kawasaki Ki-102 Redux

Derived from the Ki-96 twin-engine single-seat fighter, development of which was abandoned after three prototypes had been completed, the Kawasaki Ki-102 was intended as a two-seat attack fighter for primary deployment in the close-support role. Some assemblies of the Ki-96 prototypes were incorporated into the three Ki-102 prototypes, the first of which was completed in March 1944. A cantilever mid-wing monoplane with a conventional tail unit, retractable tailwheellanding gear and two Mitsubishi Ha-112-II radial engines, the Ki-102 accommodated its two-man crew in separate enclosed cockpits in tandem. Completion of the prototypes was followed by the construction of 20 pre-production aircraft and in October 1944 the type was ordered into production under the official designation Army Type 4 Assault Plane (Kawasaki designation Ki-102b) and production was to total 215 aircraft. With the Imperial Japanese Army still anxious to procure a twin-engine high-altitude fighter, Kawasaki modified six of the preproduction Ki-102s to serve as prototypes of such an interceptor under the designation Ki-102a. This differed from the attack fighter by having improved two-seat accommodation, a revised tail unit and  Mitsubishi Ha-112-II Ru engines with turbochargers.

Successful testing of this version in mid-1944 resulted in a high-priority production order, but problems with the turbocharged engine resulted in only about 15 being delivered to the army before the war ended. The design had also been revised to produce a night-fighter version under the designation Ki-102c, but there was only time to complete two examples. These had increased wing span, a lengthened fuselage, redesigned tail surfaces, primitive Al radar, and armament comprising two 30mm Ho-105 cannon in the underfuselage and two 20mm Ho-5 cannon mounted obliquely in the fuselage to fire forward and upward. Ki-102b aircraft, which were allocated the Allied codename 'Randy', saw comparatively little service, some being used in action over Okinawa, but the majority were held in reserve in Japan.

Versions
Ki-102
    prototypes, 3 built
Ki-102a (Type Kō)
    Externally similar to the 102b, but with turbosuperchargers that enabled the engine to maintain its rating at higher altitudes. 57 mm (2.24 in) cannon was swapped in favour of a 37 mm (1.46 in) cannon, and the 12.7 mm (.50 in) rear gun was deleted, 26 built.
Ki-102b (Type Otu)
    Ground-attack variant similar to prototypes, except with revised tail wheel, 207 built.
Ki-102c (Type Hei)
    Night Fighter version with lengthened fuselage and span. Radar under a Plexiglas dome, oblique-firing 20 mm cannons, and the 20 mm cannons in the belly replaced with 30 mm (1.18 in) cannons completed the package, 2 built.
Ki-108
    High-altitude fighter prototype with pressurised cabin, two conversions from Ki-102b aircraft using the structural improvements used on the 102c.

Mitsubishi Ki-46-III bomber destroyer

Defense interceptor/night fighter version of the Ki-46. Equipped with two 20 mm cannons in the nose and one 37 mm (1.46 in) cannon in the "Schräge Musik"-style dorsal frontal position.

By the end of the war in 1945, a desperate Japanese defensive campaign saw the ki-46 series converted into an ad hoc heavily-armed interceptor platform. The main threat to the Japanese mainland now came from the high-altitude Boeing B-29 Superfortress which could essentially act with its own level of impunity over Japanese defenses and out of reach of enemy interceptors. As a bomber interceptor, armament of the Ki-46 was upgraded to include 2 x 20mm cannons in the nose and 1 x 37mm cannon in an oblique firing position. The latter armament was intended to engage bombers from the rear and underneath - the most vulnerable area of an enemy bomber when in flight. These versions (Ki-46-III-KAI) proved adequate for the role conversion but were not as successful as anticipated. The airframe was simply not designed for the sustained firing of the large-caliber 37mm cannon, especially in its semi-vertical fitting, and the aircraft had trouble reaching its defined interception altitudes within time. Even when it did reach B-29 bombers, the aircraft lacked any armor protection or self-sealing fuel tanks and essentially made for target fodder against B-29 gunners. The Ki-46-III-KAI appeared in October of 1944 and was in operational service by the following month. When the American aircrews converted over the night operations, the tactical usefulness of the Ki-46-III interceptor was even less for they were never adapted to the night fighter role with radar or similar tracking facilities. The Ki-46-IIIb was a similar III-series mark though developed specifically for the ground attack role and produced sans the oblique-firing 37mm cannon. Several other experimental forms existed to test out engines but these came to naught while still others never materialized from the drawing boards.