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Kawasaki P-2J Neptune

Anti-Submarine Warfare / Maritime Patrol Aircraft

The Kawasaki P-2J Neptune made up the last remaining production batch of the American Lockheed Neptune maritime patrol line.
Authored By: Staff Writer | Last Edited: 7/13/2016
In 1961, work began on a new maritime patrol platform for the nation of Japan. Instead of heavily investing in the more modern, but cost prohibitive, Lockheed P-3 "Orion" being offered by the Americans, it was decided to develop a turboprop-powered version of the Lockheed P-2 "Neptune" with slight changes implemented to suit the Japanese requirement. The aircraft would serve the Japanese Maritime Self-Defense Force (JMSDF) from introduction in 1969 until retirement in 1996. Production yielded 83 examples from the period spanning 1966 to 1979.

A P-2H (P2V-7) airframe was used for the modification and a first flight of a prototype was recorded on July 21st, 1966. Since local Japanese industry was already engaged in license-production of the General Electric T64-10 series turboprop engine, replacing the Neptune's radial installations to the new engines was made easier. Each unit outputted at 2,850 horsepower and drove four-bladed propeller systems. Beyond the conventional powerplants, the new Japanese version of the aircraft was outfitted with J3-IHI-7C series turbojets for improved performance and avionics were all-modern. The changes produced an aircraft that was slightly longer than the original USN entry with greater surface area at the tailplanes and more internal volume for more fuel.

The aircraft was adopted by the JMSDF as the P-2J "Neptune". Despite the listed changes, the origins to the aircraft were readily apparent: the fuselage retained its slim profile and slab-sided approach. The flight deck sat behind and over the nose, both sections glazed over for good vision out-of-the-aircraft. Wings were mid-mounted monoplanes and each held an engine nacelle along the leading edge. The wings also showcased a noticeable amount of dihedral (upward angle) with tips carrying mission-pertinent equipment. Pods were also affixed under each wing just outboard of each engine nacelle. A ventral blister along the forward section of the fuselage housed a radome. The tail unit was conventional with its single vertical tail fin and low-set horizontal planes. The undercarriage utilized a three-point stance and was wholly retractable.

Original in-service models were known simply as "P-2J" and this constituted the sole prototype example and a further 82 "new-build" aircraft. Two of this stock were then converted for the ELectronic INTelligence (ELINT) role under the "EP-2J" designation. "UP-2J" represented four P-2J airframes converted to serve various drone-related functions.

The P-2J units served until its technological capabilities had finally been surpassed for JMSDF tastes which led to the service eventually ordered a fleet of Lockheed P-3C "Orion" aircraft anyway. The P-2J line was reduced in number gradually throughout the 1980s with the last not given up until 1993.


[ 83 Units ] :
Kawasaki - Japan / Lockheed Martin - USA
National flag of Japan Japan
- Anti-Submarine Warfare (ASW)
- Anti-Ship
- Reconnaissance (RECCE)
95.90 ft (29.23 m)
101.28 ft (30.87 m)
29.30 ft (8.93 m)
(Showcased structural dimension values pertain to the Kawasaki P-2J Neptune production model)
Empty Weight:
42,505 lb (19,280 kg)
75,001 lb (34,020 kg)
(Diff: +32,496lb)
(Showcased weight values pertain to the Kawasaki P-2J Neptune production model)
2 x IHI (General Electric) T64-10 turboprop engines developing 2,850 horsepower each with 2 x Ishikawajima-Harima J3-IHI-7C turbojet engines developing 3,085 lb of thrust each.
(Showcased powerplant information pertains to the Kawasaki P-2J Neptune production model)
Maximum Speed:
404 mph (650 kph; 351 kts)
Service Ceiling:
30,020 feet (9,150 m; 5.69 miles)
Maximum Range:
2,762 miles (4,445 km; 2,400 nm)
1,800 ft/min (549 m/min)
(Showcased performance values pertain to the Kawasaki P-2J Neptune production model; Compare this aircraft entry against any other in our database)
Up to 8,000 lb of torpedoes, depth charges, rockets, or conventional drop bombs.
(Showcased armament details pertain to the Kawasaki P-2J Neptune production model)
P-2J - Base Series Designation
P2V-Kai - Original product designation
EP-2J - ELINT models converted from P-2J; two examples.
UP-2J - Drone support platform; four examples converted from P-2J stock.

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