Http://www.aviationweek.com/aw/generic/story_generic.jsp?channel=awst&id=news/awst/2011/01/03/AW_01_03_2011_p18-279564.xml&headline=China's%20J-20%20Stealth%20Fighter%20In%20Taxi%20Tests&prev=10

China's J-20 Stealth Fighter In Taxi Tests

Dec 30, 2010

By Bill Sweetman
Washington


China’s first known stealth aircraft just emerged from a secret
 development program and was undergoing high-speed taxi tests late
last week at Chengdu Aircraft Design Institute’s airfield. Said
to be designated J-20, it is larger than most observers expected—pointing
 to long range and heavy weapon loads.

（中國J-20出現，比一般觀察家預期的要大，暗示大航程和重酬載）

Its timing, Chengdu’s development record and official statements
 cast doubt on U.S. Defense Secretary Robert Gates’s 2009 prediction
 (in support of his decision to stop production of the Lockheed Martin F-22)
 that China would not have an operational stealth aircraft before 2020.

（此機出現讓人對美國國防部長聲稱中國的五代機要2020年才能服役產生疑問。
此人以此為論據來支持停產F-22的決定）

The debut of the J-20 was announced in a November 2009 interview on Chinese
 TV by Gen. He Weirong, deputy commander of the People’s Liberation Army Air
 Force. The general said a “fourth-generation” fighter
 (Chinese terminology for a stealth fighter) would be flown in 2010-11 and be
 operational in 2017-19.

（中國的軍事將領說會在2017-19年服役）

The J-20 is a single-seat, twin-engine aircraft, bigger and heavier than the
 Sukhoi T-50 and the F-22. Comparison with ground-service vehicles points to
 an overall length of 75 ft. and a wingspan of 45 ft. or more, which would
suggest
 a takeoff weight in the 75,000-80,000-lb. class with no external load. That
in
 turn implies a generous internal fuel capacity. The overall length is close
to
that of the 1960s General Dynamics F-111, which carries 34,000 lb. of fuel.

（J-20是單座雙發戰機。75ft長，翼展45ft，無外掛起飛重量約75000-80000磅，比T-50
和F-22要大且重。）

The J-20 has a canard delta layout (like Chengdu’s J-10) with two canted,
 all-moving vertical stabilizers (like the T-50) and smaller canted ventral
fins.
The stealth body shaping is similar to that of the F-22. The flat body sides
are
aligned with the canted tails, the wing-body junction is clean, and there is
a
sharp chine line around the forward fuselage. The cant angles are greater than
 they are on the Lockheed Martin F-35, and the frameless canopy is similar
 to that of the F-22.

（J-20有前翼三角翼，傾斜全可動垂尾，以及小傾斜水平尾翼。匿蹤機身類似F-22。翼傾
角大於F-35。）

The engines are most likely members of the Russian Saturn AL-31F family, also
 used on the J-10. The production version will require yet-to-mature
indigenous
 engines. The inlets use diverterless supersonic inlet (DSI) technology,
first
adopted for the F-35 but also used by Chengdu on the J-10B—the newest
version
of the J-10—and the Sino-Pakistani JF-17 Thunder.

（引擎近似AL-31F家族，量產版會採用尚未成熟的國產引擎。進氣道為DSI）

The main landing gears retract into body-side bays, indicating the likely
 presence of F-22-style side weapon bays ahead of them. The ground clearance
 is higher than on the F-22, which would facilitate loading larger weapons
 including air-to-surface munitions. Chinese engineers at the Zhuhai air
show in November disclosed that newly developed air-to-ground weapons are
 now required to be compatible with the J-20.

（由主起落架的位置可看出其武器艙可能是類似F-22的兩側設計。起落架高度高於
F-22，暗示其可以使用大型武器。中國工程師於珠海航展曾透露新開發的空對地武
器必須要能相容於J-20）

Features at the rear of the aircraft—including underwing actuator fairings,
 axisymmetrical engine exhausts and the ventral fins—appear less
 compatible with stealth, so the J-20 may not match the all-aspect stealth
 of the F-22. There are two possible explanations for this: Either the
 aircraft seen here is the first step toward an operational design,
 or China’s requirements do not place as much stress on rear-aspect
 signatures.

（後機身設計似乎不適合匿蹤。兩個可能的解釋是：此機為開發作戰用機的第一步
，抑或中國不那麼在乎對後方的訊號）

The major open question at this point is whether the J-20 is a true
prototype,
like the T-50, or a technology demonstrator, with a status similar to the
 YF-22 flown in 1990. That question will be answered by whether, and how many,
 further J-20s enter flight testing in the next 12-24 months.

（真正的問題在J-20是原型機（如T-50）或是技術展示機（如YF-22）。這就要看未來
還有多少架J-20進行飛試即可分曉）

Developing an effective multi-mission stealthy aircraft presents challenges
 beyond the airframe, because it requires a sensor suite that uses automated
 data fusion, emission control and low-probability-of-intercept data links
 to build an operational picture for the pilot without giving away the
 aircraft’s own location.

（要做匿蹤機要各種不同科技，不是光能做出機體就行）

A rapid development program would be a challenge for China’s combat
 aircraft industry, which is currently busy: The J-10B, FC-17 and
 Shenyang’s J-11B and carrier-based J-15 are all under development.
However, the progress of China’s military aviation technology has been
 rapid since the first flight of the J-10 in 1996, owing to the
nation’s growing economy and the push by the People’s Liberation Army
for a modernized military force in all domains. Before the J-10, China’s
 only indigenous production combat aircraft were the Shenyang J-8 and
 Xian JH-7, reflecting early-1960s technology from Russia and Europe.

（中國要同時發展這麼多型號的飛機，挑戰很大）

Engine development has lagged airframe development, with reports that
 the Shenyang WS-10 engine, slated to replace Russian engines in the
J-11B, has been slow to reach acceptable reliability and durability levels.
 That may not be surprising, given that high-performance engine technology
 is founded on specialized alloys and processes that often have no other
uses.
(The existence of the J-11B, essentially a “bootleg” version of the Su-27,
 has been a strain on relationships between the Russian and Chinese
 industries.)

（引擎發展落後機體。WS-10的發展延後已使得J-11B進度落後。）

Progress with avionics may be indicated by the advent of the J-10B, with new
 features that include a canted radar bulkhead (normally associated with
an active, electronically scanned array antenna), an infrared
 search-and-track system, and housings for new electronic warfare antennas.

（航電科技可以由J-10B的進步看出：其擁有AESA, IRST，以及新的電戰系統）

One question that may go unanswered for a long time concerns the degree to
 which cyberespionage has aided the development of the J-20. U.S. defense
industry cybersecurity experts have cited 2006—close to the date when the
 J-20 program would have started—as the point at which they became aware of
 what was later named the advanced persistent threat (APT), a campaign of
 cyberintrusion aimed primarily at military and defense industries and
characterized by sophisticated infiltration and exfiltration techniques.

（J-20有可能受惠於中國透過網路戰竊自美國的機密。J-20計劃開始的日期和美國
發現代號為「先進持續威脅」（APT）對美國軍工企業發動滲透的時間接近）

Dale Meyerrose, information security vice president for the Harris Corp.
and former chief information officer for the director of national
intelligence,
 told an Aviation Week cybersecurity conference in April 2010 that the APT
 had been little discussed outside the classified realm, up to that point,
 because “the vast majority of APT attacks are believed to come from a
 single country.”

（以往APT並未被公開討論，因為美國發現APT的來源都指向單一國家）

Between 2009 and early 2010, Lockheed Martin found that “six to eight
 companies” among its subcontractors “had been totally compromised—e-mails,
 their networks, everything,” according to Chief Information Security
 Officer Anne Mullins.

（LM發現六到八個它的承包商已被完全滲透）

The way in which the J-20 was unveiled also reflects China’s use and
control of information technology to support national interests. The test
 airfield is located in the city of Chengdu and is not secure, with many
 public viewing points. Photography is technically forbidden, but reports
suggest that patrols have been permitting the use of cell phone cameras.
From Dec. 259, thes

--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 96.238.154.155
推 alienpanda  :LM說2020，土共說2019，差不多
推 QuentinHu   :不認為F-22會為此產線再開
推 Terrill     :原型機（如YF-22）或是技術展示機（
→ Terrill     :兩個似乎寫顛倒了
推 Terrill     :看到最後幾段 中國竊秘能力是不是比
推 Terrill     :蘇聯來的厲害阿
※ 編輯: ryannieh        來自: 96.238.154.155       (01/02 08:34)
→ ryannieh    :抱歉，已改過
推 rommel1     :機體比F-22重   引擎卻用AL-31  XD
推 rommel1     :推重比輸很大....
推 rommel1     :不知道是不是故意忽略? 高估J-20威脅
→ usualjoy    :美國看到別人的科技有所提升，就下
→ usualjoy    :意識的會認為是偷的他的，當時對蘇聯
→ usualjoy    :也是這樣...
推 gioiechang  :歷代三角翼的戰機好像推重比都不高..
→ gioiechang  :殲十的推重比也不高,殲十靠優異的氣
→ gioiechang  :動外型來彌補推力的不足.....
推 gs1         :F-22多生產幾架也是好事阿 科科
推 ispy03532003:果然還是靠偷技術來的
→ BinaryLife  :主要還是靠偷台灣技術
→ QuentinHu   :樓上夠酸 我笑了...
推 BUMAS       :8萬磅是什麼情況..