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Yokosuka P1Y2-S Kyokko (Aurora) - Imperial Japan, 1944

Detailing the development and operational history of the Yokosuka P1Y2-S Kyokko (Aurora) Night-Fighter / Night-Intruder Aircraft.

 Entry last updated on 4/20/2016; Authored by Staff Writer; Content ¬©

  Yokosuka P1Y2-S Kyokko (Aurora)  
Picture of Yokosuka P1Y2-S Kyokko (Aurora)

The Yokosuka P1Y2-S Kyokko was a night-fighter offshoot of the original P1Y2 medium bomber line - ninety-six were built to the standard during World War 2.

The Yokosuka P1Y2 "Kyokko" ("Aurora") became an offshoot of the original P1Y1 Medium Bomber (detailed elsewhere on this site) introduced for service into the Imperial Japanese Navy (IJN) of World War 2 during 1944. Performance of the bomber led IJN authorities to pursue a night-fighter variant of the twin-engined platform to contend with the threat had through the American Boeing B-29 "Superfortress" heavy bomber. This work led to the P1Y2-S and saw Kawanishi given the charge to convert the bomber to a night-fighter. Ninety-six aircraft were built to this standard.

The new aircraft was finalized with 2 x Mitsubishi "Kasei 25" series 14-cylinder radial piston engines of 1,850 horsepower each (the original bomber was outfitted with 2 x Nakajima "Homare 11" 18-cylinder engines). Armament was revised to include 2 x 20mm Type 99 cannons in an oblique installation, allowing upward/forward firepower against the more vulnerable bellies of Allied bombers. Additional armament included a 30mm Type 5 cannon and the ventral bomb bay, the latter giving the new aircraft the potential to conduct night time raids against ground targets of opportunity. A first flight involving a P1Y2-S prototype occurred during June of 1944. AI radar was installed in the nose (along with its external antenna structures) and the type was adopted into the IJN soon after.

The aircraft managed only a short service life in the latter stages of the war, its performance deemed unacceptable when attempting to intercept the high-flying Boeing B-29s. As a result, many of these aircraft saw conversion back to their original medium bomber roles with some serving in the late stages of the war as kamikaze weapons against Allied warships.

Another night-fighter development related to the P1Y1 became the P1Y1-S. This model carried 4 x 20mm cannons in two obliquely-angled mountings, one forward and the other aft of the cockpit, as well as a single 13mm machine gun facing aft for defense. Another change was the inclusion of 2 x Nakajima Homare 12 series engines of 1,825 horsepower output. The variant existed in very limited production and made little impact.

Yokosuka P1Y2-S Specifications

Service Year: 1944
Type: Night-Fighter / Night-Intruder Aircraft
National Origin: Imperial Japan
Manufacturer(s): Yokosuka Naval Air Technical Arsenal / Kawanishi - Imperial Japan
Total Production: 96

Structural (Crew, Dimensions, Weights)

Operating Crew (Typical): 2
Overall Length: 49.21 feet (15 meters)
Overall Width: 65.62 feet (20.00 meters)
Overall Height: 14.11 feet (4.30 meters)

Weight (Empty): 17,196 lb (7,800 kg)
Weight (MTOW): 29,762 lb (13,500 kg)

Power / Performance (Engine Type, Top Speed)

Engine: 2 x Mitsubishi "Kasei 25" 14-cylinder radial piston engines developing 1,850 horsepower each.

Maximum Speed: 283 knots (326 mph; 525 kph)
Maximum Range: 2,970 nautical miles (3,418 miles; 5,500 km)
Service Ceiling: 32,152 feet (9,800 meters; 6.09 miles)
Rate-of-Climb: 1,745 feet-per-minute (532 m/min)

Armament / Mission Payload

1 x 30mm cannon
2 x 20mm cannon in obliquely-angled mounting.

Up to 2,205lb of bombs held in a ventral bomb bay.

Global Operators (Customers, Users)

Imperial Japan

Model Variants

P1Y2-S "Kyokko" - Base Series Designation; 96 examples completed by Kawanishi; stock later reverted back to medium bomber role.

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