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Background
– Aurora Alternatives – KHI ( Kawasaki) P-X Project |
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First to Fly – a Kawasaki from Kobe “full of Eastern Promise”
The P-X is an ambitious Japanese replacement for JMSDF P-3C Orions around 2010. This “Patrol Experimental” was, in part, the Japanese
response to the anticipated high cost of the US MMA project. Of necessity, KHI (Kawasaki Heavy
Industries) took a different approach to Boeing . Whereas the P-8A is based on an existing airliner (B737), from the outset the P-X was designed for maritime
patrol. [1] The prototype P-X rolled out on in July 2007, this aircraft making its first flight
( left ) on 28 September 2007.
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While other jet-powered Aurora replacement type candidates are either at an airframe ‘demonstrator’
stage (P-8A) or concept only ( MPA320 ), the P-X is unique
among the new designs – it has reached the hardware stage and flown on schedule against the odds. KHI discovered
that its prototype was assembled with flawed rivets. [2] Then they found that the prototype’s
stabilizers were weak and the fuselage deformed during pressurization – all problems needing
rectification before production.
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It was feared that the first flight of the P-X might be delayed until December. P-X was also designed around a
new engine type – the 50 kN class Ishikawajima-Harima (IHI) XF-7 – which also experienced some
initial teething troubles. There is an element of déjà
vu here — IHI also designed engines in the ’70s for the aborted PX-L project.[3] Will the P-X have a more propitious fate ?
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Kawasaki Heavy Industries
(KHI) P-X — Specifications
| Dimensions: |
span: 38.0m, length: 35.0m, height: 12.0m |
| Powerplant: |
4 x 50 kN (11200 lbst) IHI F7-10 turbofans [4] |
| Performance: |
max speed: 830 km/h, max cruise: [n/a] |
| Weights: |
empty weight: [n/a], MTOW: 80000 kg |
| Maximum range: |
8000 km (4,320 nm, 4,970 statute miles) |
| Crew: |
3 x flight crew, systems operators [n/a] |
| Armament: |
Torpedoes, air-to-surface missiles, bombs |
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Glitches appear in all completely new designs (illustrating the advantage of starting from an existing airframe and
known engine type) but the P-X also faces other hurdles. The JMSDF plans to purchase 80 P-X but, at present,
the Japanese constitution doesn’t permit military equipment to be exported. It is rumoured that amendments
to the constitution have been considered. Unless and until such constitutional changes are passed [5] by
the Diet, the P-X program will remain limited to the JMSDF.
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[1] In this the P-X program will be the exact reverse of the P-8A. The latter is a maritime patrol derivative
of Boeing’s highly-successful 737 airliner. KHI, in contrast, built a patrol aircraft but may
offset development costs by spinning off a future YP-X civilian airliner derivative. Update:
The Japanese Ministry of Defence’s Technical Research and Development Institute site refers to the P-X prototype as a
“XP-1”.
[2] One batch of rivets from a US supplier had not been heat treated. As a result, 10,000 rivets in 161
locations had to be examined. Many of the rivets had to be drilled out and replaced. The quick P-X repair
work appears to have been at the cost of the parallel KHI C-X airlifter. The P-X was designed in parallel with this
new airlifter – the two share flight decks as well as some wing and rear fuselage
components. The C-X is a tactical transport (meant to replace Kawasaki C-1s) but could be roughly
described as a twin-engined equivalent to the C-17.
[3] PX-L configuration was similar to the P-X but the designs are not directly related. JMSDF acceptance of the P-3
ended development of the PX-L. The PX-L would be forgotten were it not for a series of bribery scandals involving
Lockheed and Japanese officials in the 1970s.
[4] These would be production engines. The prototype P-X is fitted with Ishikawajima-Harima Heavy Industries
XF-7s (X = experimental).
[5] In December 2004, Japanese export regulations were eased in the National Defense Program Outline (in effect a
defence ‘White Paper’). However, this NDPO was related to Japan’s interest in missile defence.
It only enabled the export of components, not of complete aircraft.
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