Nakajima J1N Timeline
Spring 1938: The Japanese Naval Bureau of Aeronautics staff began to draft a 13-Shi specifications
inspired by the Potez 63 in order to develop a long-range fighter capable of escorting bombers
deep into China.
June 1938: The Japanese Naval Bureau of Aeronautics approached Mitsubishi and Nakajima with
the 13-Shi specification. The aircraft was intended to fulfill requirements for a long-range multi-
seat escort fighter. It was also to fill the position of high-speed reconnaissance and night intruder.
Three-seat twin-engine long-range fighter.
Emphasis was placed on good combat maneuverability so that it could cope with single-engine
enemy fighters. Maximum speed to be 280 kt. (322 mph.) Internal fuel range of 1,300 nautical
miles (1,496 mls.) and a maximum of 2,000 naut. mls. (2,303 mls.). Armament to be one 20 mm.
cannon plus one 7.7 mm. machine gun forward firing and one 7.7 mm. firing to the rear.
Note: Both Mitsubishi and Nakajima were involved with other aircraft designs and the 13-Shi was
May 1941: First flight of the Nakajima J1N1 prototype with two twin 7.7 mm. remote-controlled
barbettes behind the cockpit and one 20 mm. + 2 x 7.7 mm. firing forward. The engines were
Nakajima Sakae 21 / 22 (1,130 hp./each) with contra-rotating propellers.The aircraft was
very overweight with sluggish handling and maneuverability.
August 1941: The J1n1 2nd prototype with trailing-edge flaps and leading-edge slots to improve
maneuverability and the 1st prototype were delivered to the IJN for service trials where they
competed with and A6M2.
October 1941: Both aircraft were found to be considerably over weight. There were problems with
the contra-rotation propellers and complex hydraulic system. The 7.7 mm. barbette were too
heavy and difficult to aim. Severe aileron vibration during rolls was encountered. Maneuverability
was quite remarkable (2nd prototype) for a twin-engine aircraft but still inadequate. Inferior in all
accounts to the A6M2 except range. The Navy decided to reject the J1N1 as a long-range escort
fighter. However, its speed was very close to the A6M2's. Nakajima was authorized to modify the
the existing frames being worked on as fast land-based long-range reconnaissance aircraft.
July 1942: The J1N1-C type 2 model 11 Reconnaissance aircraft successfully passed its flight trials
and was put into production. Reliability and ease of maintenance were improved. The was a
crew of three; pilot, radio operator/rear gunner and navigator/observer.
Engine: 2 x Nakajima Sakae 21 (non-contra-rotating)
Fuel was reduced from 2,270 liters to 1,700 liters with provisions for 2 x 330 liter drop tanks.
Armament: 1 x 13 mm. Type 2 machine gun rear firing.
Autumn 1942: Deliveries of J1N1-C began to the IJAAF.
Spring 1943: The J1N1-C began operational missions over the Solomon Islands. The Allies identified
it a fighter and gave it the code name Irving.
Note: Some were designated J1N1-R and armed with a 20 mm. Type 99 Model 1 cannon mounted in
in a spherical turret behind the pilot's seat.
Spring 1943: Commander Yasuna Kozono, commanding officer of the 251st Kokutai (Air Corps) then
based at Vunakanau Airfield at Rabaul had devised a system for obliquely-mounted cannon in the
observer's cockpit and used the J1N1-C as a night-fighter.
Note: The maintenance crews at Rabaul removed all the equipment out of the observer's cockpit and
installed 2 x 20 mm. cannon firing forward and upward at a 30 degree angle. The aircraft was
designated J1N1-C Kai and soon after intercepted and destroyed 2 B-17s of the 43rd Bomb Group.
This interception got the IJNAF's attention. They had been recognizing the need for a night fighter
and instructed Nakajima to begin manufacturing a completely new version ot the J1N1 night fighter.
August 1943: Production of the J1N1-S Gekko (Moonlight) Model 11 began at Koizumi. Two dorsal and
two ventral 20 mm. Type 99 obliquely firing cannon were installed. The individual exhaust stubs were
replaced with a collector ring. It had primitive AI Radar.
Note: Combat experience found that the downward-firing cannon were not as effective as the upward-
firing cannon and were not installed in late model aircraft. These were designated J1N1-Sa Gekko
Model 11A. Some J1N1-Sas had 3 upward firing cannon.
Note: Before the end of the war most Gekko fighters and reconnaissance aircraft were modified for
Kamikaze use (Devine Wind).
Production: Nine prototypes and 470 production aircraft were built.