Military Factory logo

Kawasaki P-2J Neptune

Japan (1969)

Detailing the development and operational history of the Kawasaki P-2J Neptune Anti-Submarine Warfare / Maritime Patrol Aircraft.

 Entry last updated on 7/13/2016; Authored by Staff Writer; Content ©

Basic Specifications
National Flag Graphic
Year: 1969
Type: Anti-Submarine Warfare / Maritime Patrol Aircraft
Manufacturer(s): Kawasaki - Japan / Lockheed Martin - USA
Production: 83

The Kawasaki P-2J Neptune made up the last remaining production batch of the American Lockheed Neptune maritime patrol line.

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.
Any available statistics for the Kawasaki P-2J Neptune Anti-Submarine Warfare / Maritime Patrol Aircraft are showcased in the areas immediately below. Categories include basic specifications covering country-of-origin, operational status, manufacture(s) and total quantitative production. Other qualities showcased are related to structural values (namely dimensions), installed power and standard day performance figures, installed or proposed armament and mission equipment (if any), global users (from A-to-Z) and series model variants (if any).
Supported Mission Types
Ground Attack
Close-Air Support
Airborne Early Warning
Electronic Warfare
Aerial Tanker
Passenger Industry
VIP Travel
Business Travel
Special Forces
Crew: 10
Length: 95.90 ft (29.23 m)
Width: 101.28 ft (30.87 m)
Height: 29.30 ft (8.93 m)
Empty Weight: 42,505 lb (19,280 kg)
MTOW: 75,001 lb (34,020 kg)

Installed Power
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.

Standard Day Performance
Maximum Speed: 404 mph (650 kph; 351 kts)
Maximum Range: 2,762 mi (4,445 km; 2,400 nm)
Service Ceiling: 30,020 ft (9,150 m; 5.69 mi)
Rate-of-Climb: 1,800 ft/min (549 m/min)

Up to 8,000 lb of torpedoes, depth charges, rockets, or conventional drop bombs.

Operators List

Series Model Variants
• 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.

Supported Weapon Systems
Graphical image of aircraft aerial rockets
Graphical image of an aircraft aerial torpedo
Graphical image of an aircraft conventional drop bomb munition