A P-1 patrol plane on the airfield of the Maritime Self-Defense Force’s Atsugi Air Base.
 
Chieko Tsuneoka/The Wall Street Journal
Japan’s next-generation surveillance plane, officially unveiled earlier this week, will enable its military to conduct longer reconnaissance missions at a time when Tokyo is paying close attention to China’s growing presence in the disputed Spratly Islands in the South China Sea.
The P-1, manufactured by Kawasaki Heavy Industries Ltd.7012.TO -3.03%, is crammed full of high-performance sensor equipment and the latest data-processing systems to detect submarines and small vessels.
The new plane, billed as the world’s first production aircraft to use fly-by-light fiber-optic cable technology, has a cruising speed of 830 kilometers an hour (515 mph), 30% faster than the P-3C patrol plane it will replace, and a range of 8,000 kilometers, an increase of more than 20%.
“Mobility to fly out to distant destination waters swiftly and operate for a long time while remaining in operational areas is necessary” for detecting submarines and other targets, said Cmdr. Jun Masuda of the Maritime Self-Defense Force’s 511 Fight Unit during a presentation of the new jet at the MSDF’s Atsugi Air Base in Kanagawa prefecture, southwest of Tokyo.
The introduction of the P-1 comes as Prime Minister Shinzo Abe’s administration is looking to pass security legislation to expand the scope of Japan’s military activities and bolster U.S.-Japan joint defense operations, partly in response to Beijing’s expanding military footprint in Asia.
Tensions have risen in recent weeks over China’s extensive land reclamation activity in the Spratlys. The U.S. hopes Japan will join its maritime air patrols over the disputed waters to check on what it sees as China’s expansionism.
The cockpit of the P-1
 
Chieko Tsuneoka/The Wall Street Journal
This week, Japan’s top uniformed officer, Adm. Katsutoshi Kawano said in an interview that Japan may join the U.S. in conducting surveillance in the South China Sea.
A Japanese P-3C aircraft has been participating in a joint search and rescue exercise this week between Japan and the Philippines in waters about 150 km from the Spratlys.
The MSDF’s public affairs office declined to comment over whether the P-1 would be dispatched to the South China Sea in the future.
Japan is buying 20 P-1 aircraft in fiscal 2015, for about ￥18.9 billion ($153 million) each. The first plane came into service in April with the MSDF’s 3rd Squadron.
Tokyo also hopes to sell the plane overseas following a relaxation of rules on weapons exports in April 2014 by the Abe administration.
Japanese Defense Minister Gen Nakatani said he spoke about the P-1 with his British counterpart Michael Fallon at a meeting to discuss bilateral defense cooperation in London in January.
Britain’s Royal Air Force is looking for a successor to its British-made Nimrod, which it abandoned in 2011.
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