With the pacifist Constitution, Japan upholds the building of armed forces with the motto "self-defense"
Japan Self-Defense Forces always insist "quality over quantity" and "priority at sea and in the air"
Maritime patrol is therefore an extremely important aspect of defense for Japan
especially in the face of China's growing power in the region
Until now, the Japan Maritime Self-Defense Force had relied on the US Lockheed P-3 "Orion"
In search of a more modern alternative platform, the Kawasaki P-1 was born
Its first flight was on September 28, 2007 and has been in service since 2013.
A total of about 60 have been built
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-optics control system
The aircraft has a length of 38 m, a wingspan of 35.4 m, a height of 12.1 m, and a maximum take-off weight of 79.7 tons
The P-1 is powered by four IHI Corporation F7 turbofan engines, with 60 kN thrust each
It can reach a top speed of 996 km/h, a cruise speed of 833 km/h, a range of 8,000 km/h, and a service ceiling of 13,520 m
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 technologies and features, particularly in terms of its avionics and missions systems
One such key feature is the use of a fly-by-optics flight control system, which essentially replaces standard metal wiring with optical fiber cables
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 magnetic anomaly detector embedded into the aircraft's tail
along with deployable sonobuoys, which is used for the detection of submerged submarines
Sophisticated acoustic systems are also used for this purpose
The P-1 has an artificial intelligence system to assist TACCO operations
similar to the SH-60K, this advanced combat direction system directs the TACCO operator to the optimal flight course to attack a submarine
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
Weapons available on the P-1 include torpedoes, mines, depth charges, air-to-surface missiles, or bombs
Multiple radar warning receivers provide all-round awareness of missile threats, which is combined with a defensive countermeasures suite