AviationWeek.com/awst AVIATION WEEK & SPACE TECHNOLOGY/JANUARY 15-FEBRUARY 1, 2015 55
Bradley Perrett Sydney
Japan may help build Airbus’s
next helicopter
A
irbus is urging Japan to base its next army utility he-
licopter on the X4, an advanced rotorcraft that the
European manufacturer is developing for the civil
market. If the ofer is accepted, the army UH-X program
could be a breakthrough in Japan’s process of entering into
the global arms market, since the military X4 would become
a partly Japanese product ofered for international sale.
Because Japan is now willing to consider arms exports,
Airbus Helicopters and long-time partner Kawasaki Heavy
Industries (KHI) do not have to consider the old, inefcient
Japanese industrial practice of complete or near-complete
license production of foreign aircraft at extremely slow rates.
Instead, they have discussed the possibility of the Japanese
company building the drive train and rotor for all X4s, says
an industry ofcial who is closely watching progress in the
program.
Joint pro-
duction would
fulfill the Jap-
anese defense
ministry’s hopes
that the army UH-X
would support a civil
export program. Con-
ceivably, KHI could
also handle final assem-
bly of X4s for the Asian civil
market, especially since the company would prob-
ably need an assembly line for those delivered to the
Japanese army.
The ministry intends to order about 150 army UH-X
helicopters over 20 years. An unrelated Japanese navy
helicopter program is also called UH-X.
A team comprising Bell and Fuji Heavy Industries (FHI)
appears to be the other main contender for UH-X, probably
ofering a version of the Bell UH-1, such as the 412 or UH-1Y
Viper. Sikorsky says its S-76D would suit the requirement,
but industry ofcials say its only possible Japanese partner,
Mitsubishi Heavy Industries, may not be interested.
Like Bell and Sikorsky, Airbus confirms its interest in the
army UH-X program, but it does not name the aircraft it
proposes as the basis for development. Its alternative ofer-
ing was the EC155 but Airbus has proposed that helicopter
for South Korea’s similar LCH-LAH program.
The X4 could prove to be a risky choice for Japan, since the
type is not even expected to fly until sometime this year. But
it would also simplify the allocation of manufacturing work,
because Airbus cannot have decided yet on the production
set-up for the type. Also, at this early stage in the program
there should still be opportunities to tailor the design to suit
Japanese military requirements, although this could under-
mine civil competitiveness.
The Japanese army is worried that it will be forced to op-
erate a basically civilian, and thus not battle-worthy, utility
helicopter, says an industry ofcial. The UH-1Y, used by the
U.S. Marine Corps, would not present that problem, although
it could have a very small civil market. The X4, UH-1Y and
Bell 412 would all meet Japan’s requirement for two engines.
The defense ministry’s development budget for the army
UH-X, ¥23-26.3 billion ($193-220 million), looks about right for
developing a military version of the X4, say industry ofcials.
Armies sometimes need more powerful engines than civil
operators do, because military versions of helicopters are
fitted with more equipment, may have to carry heavier loads,
and should have more maneuverability. But even substituting
an engine with greater output than the X4’s planned Tur-
bomeca TM800 and Pratt & Whitney Canada PW210, both
about 820 kw (1,100 hp), may be possible within the Japanese
budget, says an industry ofcial. But Airbus is aiming at an
unusually efcient drive and rotor system for the X4, so the
type may be able to cope with higher power loading than is
usual, says the ofcial.
The mass of the X4 is unknown. Airbus refers to it as a
successor to the AS365, which has a gross weight of just 4.3
metric tons in its current version, and the EC155, of 4.9 tons.
However, it is also meant to compete with the highly success-
ful AgustaWestland AW139, which, with a normal maximum
weight of 6.4 tons, is in quite a diferent class. In an earlier
phase of the UH-X program, Japan sought a
5-ton model; the ministry now declines to
state its current specification, to avoid
prejudicing the competition.The UH-1Y, able to fly at 8.4 tons, would be even further
from Japan’s requirement, but the Bell 412, a civil derivative
of the UH-1, has a gross weight of 5.4 tons. FHI built the
UH-1Hs and UH-1Js that Japan is seeking to replace, which
enhances the industrial appeal of Bell’s ofering.
Indicating the power requirements for a modern battle-
field utility helicopter in this class, the British Army’s Agus-
taWestland AW159 Wildcat, of 6 tons gross weight, has two
CTS800 engines, each with a maximum continuous output
of 955 kw, from LHTEC, a joint venture between Rolls-Royce
and Honeywell. Its power loading is therefore 3.1 kg per kw.
The ministry hopes to launch UH-X development by March- Bidders are awaiting a request for proposals, but the
ministry may first issue a request for comment to the indus-
try, seeking guidance on how it should proceed. c
X4 on Offer
Details of the X4 are closely held. Airbus is proposing
that KHI help build it.