Designed as a replacement for Japanese P-3 Orion's, (themselves built under license in Japan), this rather unique aircraft is most unusual for a maritime patrol aircraft of recent decades, in that it's not a converted civil or other military airframe.
Japan is also building a twin CF-6 powered military transport, this high winged cargo hauler is to share many components with the XP
-1, not that this is immediately obvious externally.
Not the first time that Japan has done something different in the MPA field, in the 50's they had a large force of P-2 Neptunes.
While most other users replaced them with P-3's, Japan built a further uniquely modernized P-2 version, with turboprops replacing the piston engines of the Neptunes.
This version actually remained in production until the late 70's, long after most other regular Neptunes worldwide had been replaced.
Then in the 70's Japan produced a new 4 turboprop large flying boat, in both anti sub and search and rescue versions, long after flying boats in military service had gone from the rest of the world.
The ASW flying boats have left service, but the SAR ones remain and a new, modernized version is in production.
Export prospects for XP
-1, and any other military product by Japan, is very seriously limited by it's defensive post WW2 constitution, which prohibits virtually all military exports.
From tanks to jet trainers, it's all not
for export sale.
The motivation for this is in part, despite these limitations, is to keep a competent capability for military and aerospace technology, beyond license building mostly US types.
Japan has had very limited success with aerospace exports, in stark contrast to virtually every other industrial field.
But they want to retain the ability, be it by their own space launch vehicles or aircraft.
With the recent launch of the Mitsubishi Regional Jet, the first airliner from japan since the moderate selling YS
-11 turboprop of the 1960's, their reasoning here becomes apparent.
They want to stay in the game.
This seemingly eccentric looking XP
-1 maritime aircraft is a part of that.
[Edited 2008-12-11 12:46:11]