Y-20

hina’s Ministry of National Defense has formally acknowledged
development of the Y-20 military airlifter, four days after images of a
prototype appeared on a Chinese Internet forum devoted to military
matters. The aircraft was shown undergoing taxi tests at an airfield in
Northwestern China, supposedly affiliated with the developer, Xian
Aircraft Industry Group of the state-owned Aviation Industry Corporation
of China (Avic), according to Chinese reports. Also at the site was a
J-20 fighter jet prototype.
Two Y-20 prototypes have been produced to date, one for
flight-testing and the other for static tests. The Y-20 is a four-engine
turbofan designed as a strategic airlifter and is controversially
similar in configuration to the Boeing C-17. In February 2008, Greg
Chung, an American citizen of Chinese origin who had worked for Boeing
in southern California as a stress analyst, was charged with passing
aerospace trade secrets, including those involving the C-17 program, to
China. That same month, AIN published a CAD/CAM
drawing of the Y-20 design, taken from a video promoting Avic, that
Western analysts had previously overlooked. In 2010 Chung was convicted
and sentenced to 15 years in prison.

The Y-20 is said to have flown for the first time last November, but
other Chinese Internet sources have stated that the maiden flight will
not occur until sometime this month. The prototypes are reportedly
powered by Russian-made D30KP2s, which China has received thanks to its
purchase of Ilyushin Il-76 airlifters. In late November, AIN reported that China is buying another 10 Il-76s from Russia. Our comment then, that China had abandoned its indigenous airlifter project, was evidently incorrect.

It is not yet known whether China will be able to equip production
models of the Y-20 with its own turbofans. However, at the recent Zhuhai
Airshow, officials from Avic reported significant progress in the
development of indigenous turbofans. Production versions of the Y-20
could therefore dispense with the Russian powerplants.

The payload of the Y-20 is reported to be 60 tonnes, short of the
77-tonne capacity of the C-17. Its maximum takeoff weight is between 200
and 220 tonnes. The Y-20 is thought to be capable of carrying China’s
main battle tank, the Type 99. Its range is reported to be 4,000 km,
enough to cover the whole of China. If taking off from Shanghai, it
could reach Guam.

An article on one Chinese-language website noted that a fleet of 100
Y-20s would put China at the top of the power-projection league in the
Asia-Pacific region. But China would need to produce 300 Y-20s to match U.S. strategic airlift capability, the website noted.

If ever there were an aircraft that should grow in capability,
China's newly flown Y-20 airlifter would be it. The prototype that took
to the air on Jan. 26 mates what looks like a modern airframe with
obsolete 1960s-technology engines. Together, they probably represent no
more than a serviceable design standard, offering only modest advances
in capability over the Ilyushin Il-76 that China already operates.
But
a better engine is under development for the Y-20. If and when China's
technologically challenged aero-engine industry can get that high-bypass
turbofan ready, then the airlifter should surge in performance. More
distantly, a truly modern engine under development for the Comac C919
airliner could also be available.
Successful development of the
Y-20 airframe is in itself an important accomplishment for the Chinese
industry, which in more than six decades of Communist history has been
only slowly and haltingly weaning itself from copying foreign types,
mostly Soviet-era Russian designs. Underscoring this point, the Y-20 is
the largest indigenous Chinese aircraft built so far, exceeding the
unsuccessful Y-10 airliner tested in the early 1980s.
The Y-20
will not enter service before 2017, according to two Chinese military
academics, Zhang He and Li Wei, writing in China Youth Daily, a major
national newspaper. They also say that the Y-20 airframe incorporates
composite materials (although most of it appears to be aluminum) and a
“supercritical” wing. It is not clear whether the objective is to have a
new engine ready by service entry.
The Y-20 is an entirely new
design, even though it is close in size and shape to the Il-76, which
uses the same Saturn D-30KP medium-bypass engine as the Chinese
airlifter's prototype. Compared with the Il-76, the Y-20 has a shorter
wingspan and a shorter, but slightly wider, fuselage. The Y-20 is larger
than the Airbus A400M and has about the same fuselage diameter, but is
much smaller than the Boeing C-17.
Specifications estimated by
Aviation Week (see table) and including dimensions determined
photometrically, vary from figures quoted by Zhang and Li. The academics
say the Y-20's span is 45 meters (148 ft.), length 47 meters, height 15
meters, gross weight “over 200 tons” and payload 66 tons. They give no
source, but their figures could be preliminary numbers estimated in
2006, when the project was launched after about 15 years of study.
Comparison with the Il-76 suggests that the published weight and payload
figures are too high for a version fitted with the D-30KP.
In
late 2009, Hu Xiaofeng, the general manager of Avic Aircraft—the
large-airplane specialist subsidiary of aeronautics group Avic—said the
Y-20 was in the “200-ton class” and would be unveiled at the end of that
year. But it was not unveiled then, suggesting that the airframe or
engine program had hit trouble. The Xian Aircraft plant is building the
Y-20, which was rolled out in December 2012.
The Y-20 follows the configuration set by the Lockheed C-141, with a
high-mounted wing, moderately swept to combine good low-speed
performance with reasonable cruising speed, fuselage-mounted landing
gear and a T-tail. (Since the C-141, all successful jet airlifters have
used that configuration, except the An-124, which has a low tail.) The
Y-20's wing has full-span slats and triple-slotted trailing-edge flaps,
the latter comprising two articulated segments with a fixed vane on the
forward surface. The engines are hung low as on the Il-76—in its current
form at least, the Y-20 does not use externally blown flaps in the same
way as the C-17.
The ailerons can also droop to increase lift
at low speeds, and large spoilers are fitted for roll control and lift
dumping. Like the C-17, the Y-20 has a four-piece rudder, with upper and
lower double-hinged segments. This provides both redundancy and the
ability to use higher deflection on the lower half than on the upper
rudder panels, reducing loads on the vertical tail.
In
comparison with the Il-76, a smaller cockpit for just three crew members
should have helped designers to increase cargo volume. Chinese media
stress that the aircraft is fatter than the Il-76, the skinniest of the
strategic airlifters now in service, though the difference may not be
great. Extra diameter should help in stowing outsize items such as
helicopters and engineering vehicles, but the Y-20's cargo bay is
shorter than the Il-76's.
The landing gear looks similar in
layout to the A400M's, with three separate twin-wheel units on each
side. Operating jet airlifters from truly unimproved surfaces is more
spectacular than practicable, but the Y-20 should be as good as any of
its contemporaries in this regard. Zhang and Li say it can operate from
“relatively simple” fields. The nose wheel can pivot 90 deg., they add,
giving a detail that suggests they have been well-briefed. (Zhang is on
the faculty of the Command College of the Second Artillery and Li is of
the National Defense University.)
The Y-20's overall size and
weight are such that it could be an effective aircraft with D-30KP
engines, which China already imports for its H-6K cruise-missile
carrier. At least 20% more thrust will probably be available from the
Chinese turbofan that Avic Engine is developing at Shenyang, possibly
under the name WS-20. It is believed to be a derivative of the WS-10
Taihang fighter engine.
In contrast to the medium-bypass D-30KP,
it will have a high bypass ratio, making it comparable with the CFM56,
to which it may be related (AW&ST Nov. 7, 2011, p. 28). The Y-20
must have entered flight testing with the D-30KP because the Chinese
engine was not ready—perhaps not fully developed or maybe just not
trusted for early flights.
A more distant prospect is the
CJ-1000, which Avic Commercial Aircraft Engines is developing for the
Comac C919 airliner as an alternative to the CFM Leap-1 and with the aim
of matching the performance of that Franco-U.S. engine. CJ-1000
development faces great technical challenges but is probably being well
funded. With abundant thrust and, it is hoped, world-class efficiency,
the CJ-1000 would transform the performance of the Y-20.
The
prospective use of the Y-20 raises a contradiction that has become
familiar as the Chinese navy has developed its amphibious assault
capability and commissioned an aircraft carrier. China's government
consistently downplays its interest in power projection. And, like all
authoritarian states, it strongly promotes the principle of
non-intervention in the internal affairs of other countries. No wonder,
then, that state media stress the humanitarian and disaster-relief role
of the Y-20. Those will undoubtedly be prominent roles of the Y-20,
internationally as well as domestically, helping China's image abroad.

Admin a écrit:Pascal, je ne partage pas ton avis
Sinon

http://www.aviationweek.com/Article.aspx?id=/article-xml/AW_02_04_2013_p26-542650.xml&p=1

If ever there were an aircraft that should grow in capability,
China's newly flown Y-20 airlifter would be it. The prototype that took
to the air on Jan. 26 mates what looks like a modern airframe with
obsolete 1960s-technology engines. Together, they probably represent no
more than a serviceable design standard, offering only modest advances
in capability over the Ilyushin Il-76 that China already operates.
But
a better engine is under development for the Y-20. If and when China's
technologically challenged aero-engine industry can get that high-bypass
turbofan ready, then the airlifter should surge in performance. More
distantly, a truly modern engine under development for the Comac C919
airliner could also be available.
Successful development of the
Y-20 airframe is in itself an important accomplishment for the Chinese
industry, which in more than six decades of Communist history has been
only slowly and haltingly weaning itself from copying foreign types,
mostly Soviet-era Russian designs. Underscoring this point, the Y-20 is
the largest indigenous Chinese aircraft built so far, exceeding the
unsuccessful Y-10 airliner tested in the early 1980s.
The Y-20
will not enter service before 2017, according to two Chinese military
academics, Zhang He and Li Wei, writing in China Youth Daily, a major
national newspaper. They also say that the Y-20 airframe incorporates
composite materials (although most of it appears to be aluminum) and a
“supercritical” wing. It is not clear whether the objective is to have a
new engine ready by service entry.
The Y-20 is an entirely new
design, even though it is close in size and shape to the Il-76, which
uses the same Saturn D-30KP medium-bypass engine as the Chinese
airlifter's prototype. Compared with the Il-76, the Y-20 has a shorter
wingspan and a shorter, but slightly wider, fuselage. The Y-20 is larger
than the Airbus A400M and has about the same fuselage diameter, but is
much smaller than the Boeing C-17.
Specifications estimated by
Aviation Week (see table) and including dimensions determined
photometrically, vary from figures quoted by Zhang and Li. The academics
say the Y-20's span is 45 meters (148 ft.), length 47 meters, height 15
meters, gross weight “over 200 tons” and payload 66 tons. They give no
source, but their figures could be preliminary numbers estimated in
2006, when the project was launched after about 15 years of study.
Comparison with the Il-76 suggests that the published weight and payload
figures are too high for a version fitted with the D-30KP.
In
late 2009, Hu Xiaofeng, the general manager of Avic Aircraft—the
large-airplane specialist subsidiary of aeronautics group Avic—said the
Y-20 was in the “200-ton class” and would be unveiled at the end of that
year. But it was not unveiled then, suggesting that the airframe or
engine program had hit trouble. The Xian Aircraft plant is building the
Y-20, which was rolled out in December 2012.
The Y-20 follows the configuration set by the Lockheed C-141, with a
high-mounted wing, moderately swept to combine good low-speed
performance with reasonable cruising speed, fuselage-mounted landing
gear and a T-tail. (Since the C-141, all successful jet airlifters have
used that configuration, except the An-124, which has a low tail.) The
Y-20's wing has full-span slats and triple-slotted trailing-edge flaps,
the latter comprising two articulated segments with a fixed vane on the
forward surface. The engines are hung low as on the Il-76—in its current
form at least, the Y-20 does not use externally blown flaps in the same
way as the C-17.
The ailerons can also droop to increase lift
at low speeds, and large spoilers are fitted for roll control and lift
dumping. Like the C-17, the Y-20 has a four-piece rudder, with upper and
lower double-hinged segments. This provides both redundancy and the
ability to use higher deflection on the lower half than on the upper
rudder panels, reducing loads on the vertical tail.
In
comparison with the Il-76, a smaller cockpit for just three crew members
should have helped designers to increase cargo volume. Chinese media
stress that the aircraft is fatter than the Il-76, the skinniest of the
strategic airlifters now in service, though the difference may not be
great. Extra diameter should help in stowing outsize items such as
helicopters and engineering vehicles, but the Y-20's cargo bay is
shorter than the Il-76's.
The landing gear looks similar in
layout to the A400M's, with three separate twin-wheel units on each
side. Operating jet airlifters from truly unimproved surfaces is more
spectacular than practicable, but the Y-20 should be as good as any of
its contemporaries in this regard. Zhang and Li say it can operate from
“relatively simple” fields. The nose wheel can pivot 90 deg., they add,
giving a detail that suggests they have been well-briefed. (Zhang is on
the faculty of the Command College of the Second Artillery and Li is of
the National Defense University.)
The Y-20's overall size and
weight are such that it could be an effective aircraft with D-30KP
engines, which China already imports for its H-6K cruise-missile
carrier. At least 20% more thrust will probably be available from the
Chinese turbofan that Avic Engine is developing at Shenyang, possibly
under the name WS-20. It is believed to be a derivative of the WS-10
Taihang fighter engine.
In contrast to the medium-bypass D-30KP,
it will have a high bypass ratio, making it comparable with the CFM56,
to which it may be related (AW&ST Nov. 7, 2011, p. 28). The Y-20
must have entered flight testing with the D-30KP because the Chinese
engine was not ready—perhaps not fully developed or maybe just not
trusted for early flights.
A more distant prospect is the
CJ-1000, which Avic Commercial Aircraft Engines is developing for the
Comac C919 airliner as an alternative to the CFM Leap-1 and with the aim
of matching the performance of that Franco-U.S. engine. CJ-1000
development faces great technical challenges but is probably being well
funded. With abundant thrust and, it is hoped, world-class efficiency,
the CJ-1000 would transform the performance of the Y-20.
The
prospective use of the Y-20 raises a contradiction that has become
familiar as the Chinese navy has developed its amphibious assault
capability and commissioned an aircraft carrier. China's government
consistently downplays its interest in power projection. And, like all
authoritarian states, it strongly promotes the principle of
non-intervention in the internal affairs of other countries. No wonder,
then, that state media stress the humanitarian and disaster-relief role
of the Y-20. Those will undoubtedly be prominent roles of the Y-20,
internationally as well as domestically, helping China's image abroad.

tout cela reste à confirmer, notamment avec le C919
Mais le japon n'a pas moins à prouver avec le MRJ et les C-2 et P-1 !

BEIJING, March 3 (Xinhua) -- China on Saturday completed two more
ground slide tests for Y-20, its biggest home-grown transport aircraft,
following its successful January maiden flight, the air freighter's
chief designer said.

Tang Changhong, chief designer for Y-20, or Transport-20, revealed
more details about the multi-function jumbo transport jet in an
interview with Xinhua on the sidelines of the annual session of China's
top political advisory body, which opened on Sunday afternoon.

"The successful test flight of Y-20 marks a milestone in China's
aviation industry and we're moving a step closer toward building a
strategic air power for the country," said Tang, who is a member of the
12th National Committee of the Chinese People's Political Consultative
Conference, the country's top political advisory body.

Following the latest tests at a center in west China, Tang said it
took five years for Chinese designers to manufacture and test-fly the
jumbo air freighter.

"Compared with heavy-lift transport aircraft developers in foreign
countries, our development cycle is pretty fast," said Tang, who once
served as the chief designer for China's fighter-bomber jet JH-7A.

Currently, large strategic air freighters in active service around
the world include the Antonov An-225, the Ilyushin Il-76 and the Boeing
C-17 Globemaster III.

According to the chief designer, the Y-20 has a traditional layout
using tricycle landing gear and two 90-degree-deflecting wheels on the
nose gear.

Tang noted the aircraft can be used in rescue relief efforts in
earthquakes and other disasters, and will improve the Chinese military's
rapid deployment capabilities.

Tang believes the Y-20 will serve as China's jumbo transport aircraft "over a very long period of time" in the future.

The Ministry of Defense confirmed shortly after the successful test
flight on Jan. 26 that the Y-20, mainly developed by the Xi'an Aircraft
Industry (Group) Company Ltd., has the highest load-carrying capacity of
66 tonnes, a fuselage length of 47 meters, a wingspan of 45 meters and a
height of 15 meters, and bears the maximum take-off weight of 200
tonnes.

In voluntarily releasing news about Y-20's test flights, Chinese
aircraft designers have shown their confidence and greatly boosted
military transparency, according to Tang.

"The development and testing of high-end military technology and
equipment is in line with China's defense and security policy that is
purely defensive in nature," he added.

The official codename of the aircraft is Kunpeng, named after a
legendary bird in Chinese mythology that can fly thousands of miles.