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-optics 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. Export customers are also being sought for the type as part of a general loosening of Japanese military export restrictions.
Development
Observing that its fleet of P-3C aircraft had been in service for some time, the JMSDF began searching for a replacement maritime patrol aircraft. Since other similar aircraft produced abroad did not meet the JMSDF's requirements, the development of a purpose-built indigenous aircraft became necessary. The Japanese Defense Agency (JDA) submitted the domestic development of a P-X maritime patrol aircraft as part of its April 2001 – March 2006 Five-Year Defense Plan. In 2001, following its earlier proposal, the Kawasaki Aerospace Company received prime contractor status for the P-X program, as well as the adjacent C-X program for a next generation cargo aircraft; this selection process occurred almost 30 years since the previous large-scale domestic development of an aircraft in Japan.
The P-X shares some components with the C-X, later designated as the twin-engined Kawasaki C-2, another indigenously developed aircraft to replace the Kawasaki C-1 and C-130H Hercules cargo aircraft. Although the P-X and C-X designs were originally independent, it was decided that having common components to both designs would be useful. The JDA mandated that the two aircraft share identical body components; common components include the cockpit windows, outer wings, horizontal stabilizer, and other systems. Internal shared parts include the auxiliary power unit, cockpit panel, flight control system computer, anti-collision lights, and gear control unit. Due to the different roles of the two aircraft, they remain distinctly separate. The sharing of development resources had allowed for a large reduction in overall development costs which, when including the C-2, were reported in 2007 as being .
In addition to a level of commonality with the C-2, one proposed derivative of the P-1 is a civilian airliner, the proposed project has typically been referred to as the Kawasaki YPX. If development is pursued, the YPX would make extensive use of technology and components of the P-1, such as the wingbox, empennage, and fuselage.
An indigenously produced turbofan engine, the IHI Corporation F7, was also developed to power the P-X. By April 2004, the JDA had completed a successful evaluation of five XF7 research engines, by which point it was viewed as being the sole candidate powerplant for the P-X program. In May 2005, the IHI Corporation received a contract for an additional seven XF-7 test engines from the JDA following the completion of initial tests in December 2004, four of these engines were to equip the first flight test aircraft. The Full Authority Digital Engine Control (FADEC)-equipped F7 engine had a bypass ratio of 8:1, which was reported as being substantially higher than rivals such as the General Electric CF34-8E.
In April 2004, Japan and US extended discussions on potential cooperative efforts on the P-X and US Navy's Multi-mission Maritime Aircraft (MMA) programmes; options ranged from terminating the P-X program to participate in the US-led MMA program to incorporating some of the MMA's technology onto the P-X to reduce costs. The Japanese Defence Ministry ultimately opted to persist with the P-X program, stating that: "there was a possibility that foreign aircraft would not satisfy the required capability and there was a possibility that foreign aircraft would not meet the required period of introduction...it is necessary to domestically develop the aircraft". In addition to the P-1, studies were also conducted into the use of ship-based UAVs to support maritime aviation activities.
