The Aichi S1A was designed as a Japanese night fighter to replace the Nakajima J1N1-S Gekkou.
Similar to the Gekkou, it was planned to have radar capabilities to defend against B-29 air raids over Japan.
However, due to challenges in addressing design flaws, such as the underpowered Nakajima Homare engines requested by the Navy, the development of the S1A took longer than expected, and no aircraft were finished before the end of the war.
The Denko’s service weight exceeded ten thousand kilograms due to the presence of special equipment such as oxygen injection.
However, the turbocharger’s distant placement from the engine led to numerous issues.
As the initial prototypes’ engines failed to meet Navy standards, only two aircraft were produced.
There were plans for two more aircraft, but they were ultimately cancelled.
These additional planes would have been equipped with the more potent Mitsubishi HI MK9A Ru or MK10A Ru engines.
Furthermore, in December 1944, the Tōnankai earthquake caused significant damage to the aircraft factories and prototypes.
Subsequently, on June 9, 1945, airstrikes targeted Aichi Kokuki and Aichi Tokei Denki Seizo Co. Ltd., resulting in the explosion of the S1A first prototype.
This incident compelled the relocation of the second prototype to the large Sadakazu factory in Gifu for assembly.
However, on July 9, another airstrike demolished the second prototype.
Specifications
Crew
2
Length
49 ft 6.5 in (15.1 m)
Wingspan
57 ft 5 in (17.5 m)
Height
15 ft 1.5 in (4.61 m)
Wing area
505.902 sq ft (47.0 m2)
Empty weight
16,138 lb (7,320 kg)
Gross weight
22,443 lb (10,180 kg)
Max take-off weight
25,375 lb (11,510 kg)
Powerplant
2 × Nakajima NK9K-S,
2,000 hp (1,500 kW) each at take-off
Propellers
4-bladed
Performance
Maximum speed
360 mph (580 km/h, 318 kn)
Cruise speed
273 mph (440 km/h, 240 kn)
Range
1,054 mi (1,697 km, 916 nmi)
Ferry range
1,553 mi (2,500 km, 1,373 nmi)
Service ceiling
39,370 ft (12,000 m)
Wing loading
44.4 lb/sq ft (126.6 kg/m2)
Armament
Guns
2× fuselage mounted forward firing 30mm Type 5 cannon
2× fuselage mounted forward firing 20mm Type 99 model 1 cannon
2× dorsal turret mounted 20mm Type 99 model 2 cannon.
Sources
Wings of the Rising Sun Uncovering the Secrets of Japanese Fighters and Bombers of World War II-Mark Chambers.
Japanese Imperial Army Navy Aircraft Color Markings-Koku Fan 42.
Japanese Code Names-Richard M Bueschel.
Japanese Aircraft-John Stroud.
Japanese Aircraft, 1910-1941-Robert Mikesh & Shorzoe Abe.
Japanese Aircraft of the Pacific War-Rene Francillon.
Japanese Aircraft Interiors, 1940-1945-Robert C. Mikesh.
Japanese Aircraft Equipment 1940-45-Robert C Mikesh.
Famous Airplanes of the World-47, Imperial Japanese Navy Reconnaissance Seaplanes.
