The Kawasaki P-1 (previously P-X, XP-1) is a Japanese maritime patrol aircraft developed and manufactured by Kawasaki Aerospace Company. Unlike many maritime patrol aircraft, which are typically conversions of civilian designs, the P-1 is a purpose-built maritime aircraft with no civil counterpart and was designed from the onset for the role. It has the distinction of being the first operational aircraft in the world to make use of a fly-by-light control system. The P-1 has entered service with the Japan Maritime Self-Defense Force (JMSDF) as a replacement for the P-3C Orion. On 26 March 2013, the JMSDF took delivery of the first two operational P-1 aircraft. It is broadly equivalent to the US Boeing P-8 Poseidon. Export customers are also being sought for the type as part of a general loosening of Japanese military export restrictions.
The Kawasaki P-1 is a purpose-built maritime patrol aircraft equipped with four podded IHI F7-10 turbofan engines underneath the low-set wings. The four-engine low-wing loading design adopted for the P-1 results in a flight profile with better maneuverability and stability at low-speed, low-altitude flight and allows the aircraft to continue its mission in the event of a single engine failure as well as greater operational survivability, the high-bypass engines provide for quiet, fuel-efficient operation. The P-1 has reduced transit times in comparison to turboprop-powered competitors, and the turbofans are quieter, making it more difficult for submerged submarines to detect it acoustically.
The P-1 is equipped with many newly developed technology and features, particularly in terms of its avionics and missions systems. One such key feature is the use of a fly-by-light flight control system. This has the effect of decreasing electro-magnetic disturbances to the sensors in comparison to more common fly-by-wire control systems. The P-1 is the first production aircraft in the world to be equipped with such a flight control system. Various onboard systems are provided by Honeywell, who is the largest non-Japanese supplier to the project, such as the auxiliary power unit, environmental and pressurization control systems, ram air turbine, sonobuoy dispensers and elements of the avionics.
The P-1 is equipped with various sensors to enable the aircraft to perform its primary purpose of detecting submarines and surface vessels; these include the Toshiba HPS-106 active electronically scanned array (AESA) radar which uses a total of four antennas to provide 360 degree coverage, and Infrared/Light detection systems for surface detection. The P-1 is also furnished with a CAE Inc.-built magnetic anomaly detector (MAD) embedded into the aircraft’s tail, along with deployable sonobuoys, which is used for the detection of submerged submarines.
The aircraft has a lot of room for the armament. A large bomb bay housed within the main fuselage, similar in size to that of the Hawker Siddeley Nimrod’s, contains the bulk of the aircraft’s munitions, the bomb bay is supplemented by a total of eight external hardpoints mounted on the wings. The P-1 can carry a US AGM-84 Harpoon or Japanese ASM-1C anti-ship missiles, AGM-65 Maverick air-to-ground missiles also carry various torpedos, mines and depth charges. Armaments are managed by a Smith Aerospace-built stores management system, which includes a newly developed Universal Stores Control Unit (USCU) capable of accommodating hundreds of different munitions, including future ones and precision weapons. Multiple radar warning receivers provide all-round awareness of missile threats, which is combined with a defensive countermeasures suite.