『每日軍事武器鑑賞』－ JSF 聯合戰術打擊機

克里斯Chris

Joint Strike Fighter (JSF)

On October 26, 2001, the Defense Department selected Lockheed Martin's F-35 as the winner of the competition to manufacture the Joint Strike Fighter. Click here for more information.
The Joint Strike Fighter (JSF) is a multi-role fighter optimized for the air-to-ground role, designed to affordably meet the needs of the Air Force, Navy, Marine Corps and allies, with improved survivability, precision engagement capability, the mobility necessary for future joint operations and the reduced life cycle costs associated with tomorrow’s fiscal environment. JSF will benefit from many of the same technologies developed for F-22 and will capitalize on commonality and modularity to maximize affordability.

The 1993 Bottom-Up Review (BUR) determined that a separate tactical aviation modernization program by each Service was not affordable and canceled the Multi-Role Fighter (MRF) and Advanced Strike Aircraft (A/F-X) program. Acknowledging the need for the capability these canceled programs were to provide, the BUR initiated the Joint Advanced Strike Technology (JAST) effort to create the building blocks for affordable development of the next-generation strike weapons system. After a review of the program in August 1995, DoD dropped the "T" in the JAST program and the JSF program has emerged from the JAST effort. Fiscal Year 1995 legislation merged the Defense Advanced Research Projects Agency (DARPA) Advanced Short Take-off and Vertical Landing (ASTOVL) program with the JSF Program. This action drew the United Kingdom (UK) Royal Navy into the program, extending a collaboration begun under the DARPA ASTOVL program.
The JSF program will demonstrate two competing weapon system concepts for a tri-service family of aircraft to affordably meet these service needs:

USAF-Multi-role aircraft (primarily air-to-ground) to replace F-16 and A-10 and to complement F-22. The Air Force JSF variant poses the smallest relative engineering challenge. The aircraft has no hover criteria to satisfy, and the characteristics and handling qualities associated with carrier operations do not come into play. As the biggest customer for the JSF, the service will not accept a multirole F-16 fighter replacement that doesn't significantly improve on the original.

USN-Multi-role, stealthy strike fighter to complement F/A-18E/F. Carrier operations account for most of the differences between the Navy version and the other JSF variants. The aircraft has larger wing and tail control surfaces to better manage low-speed approaches. The internal structure of the Navy variant is strengthened up to handle the loads associated with catapult launches and arrested landings. The aircraft has a carrier-suitable tailhook. Its landing gear has a longer stroke and higher load capacity. The aircraft has almost twice the range of an F-18C on internal fuel. The design is also optimized for survivability.

USMC-Multi-role Short Take-Off & Vertical Landing (STOVL) strike fighter to replace AV-8B and F/A-18A/C/D. The Marine variant distinguishes itself from the other variants with its short takeoff/vertical landing capability.

UK-STOVL (supersonic) aircraft to replace the Sea Harrier. Britain's Royal Navy JSF will be very similar to the U.S. Marine variant.

The JSF concept is building these three highly common variants on the same production line using flexible manufacturing technology. Cost benefits result from using a flexible manufacturing approach and common subsystems to gain economies of scale. Cost commonality is projected in the range of 70-90 percent; parts commonality will be lower, but emphasis is on commonality in the higher-priced parts.

克里斯Chris

The JSF concept is building these three highly common variants on the same production line using flexible manufacturing technology. Cost benefits result from using a flexible manufacturing approach and common subsystems to gain economies of scale. Cost commonality is projected in the range of 70-90 percent; parts commonality will be lower, but emphasis is on commonality in the higher-priced parts.

The Lockheed Martin X-35 concept for the Marine and Royal Navy variant of the aircraft uses a shaft-driven lift-fan system to achieve Short-Takeoff/Vertical Landing (STOVL) capability. The aircraft will be configured with a Rolls-Royce/Allison shaft-driven lift-fan, roll ducts and a three-bearing swivel main engine nozzle, all coupled to a modified Pratt & Whitney F119 engine that powers all three variants.

The Boeing X-32 JSF short takeoff and vertical landing (STOVL) variant for the U.S. Marine Corps and U.K. Royal Navy employs a direct lift system for short takeoffs and vertical landings with uncompromised up-and-away performance.

Key design goals of the JSF system include:

Survivability: radio frequency/infrared signature reduction and on-board countermeasures to survive in the future battlefield--leveraging off F-22 air superiority mission support
Lethality: integration of on- and off-board sensors to enhance delivery of current and future precision weapons
Supportability: reduced logistics footprint and increased sortie generation rate to provide more combat power earlier in theater
Affordability: focus on reducing cost of developing, procuring and owning JSF to provide adequate force structure

JSF’s integrated avionics and stealth are intended to allow it to penetrate surface-to-air missile defenses to destroy targets, when enabled by the F-22’s air dominance. The JSF is designed to complement a force structure that includes other stealthy and non-stealthy fighters, bombers, and reconnaissance / surveillance assets. JSF requirements definition efforts are based on the principles of Cost as an Independent Variable: Early interaction between the warfighter and developer ensures cost / performance trades are made early, when they can most influence weapon system cost. The Joint Requirements Oversight Council has endorsed this approach.
The JSF’s approved acquisition strategy provides for the introduction of an alternate engine during Lot 5 of the production phase, the first high rate production lot. OSD is considering several alternative implementation plans which would accelerate this baseline effort.

克里斯Chris

Program Status

The focus of the program is producing effectiveness at an affordable price—the Air Force’s unit flyaway cost objective is $28 million (FY94$). This unit recurring flyaway cost is down from a projected, business as usual,cost of $36 million. The Concept Demonstration Phase (CDP) was initiated in November 1996 with the selection of Boeing and Lockheed Martin. Both contractors are: (1) designing and building their concept demonstration aircraft, (2) performing unique ground demonstrations, (3) developing their weapon systems concepts. First operational aircraft delivery is planned for FY08.

The JSF is a joint program with shared acquisition executive responsibilities. The Air Force and Navy each provide approximately equal shares of annual funding, while the United Kingdom is a collaborative partner, contributing $200 million to the CDP. CDP, also known as the Program Definition and Risk Reduction (PDRR) phase, consists of three parallel efforts leading to Milestone II and an Engineering and Manufacturing Development (EMD) start in FY01:

Concept Demonstration Program. The two CDP contracts were competitively awarded to Boeing and Lockheed Martin for ground and flight demonstrations at a cost of $2.2 billion for the 51-month effort, including an additional contract to Pratt & Whitney for the engine. Each CDP contractor will build concept demonstrator aircraft (designated X-32/35). Each contractor will demonstrate commonality and modularity, short take-off and vertical landing, hover and transition, and low-speed carrier approach handling qualities of their aircraft.

Technology Maturation. These efforts evolve key technologies to lower risk for EMD entry. Parallel technology maturation demonstrations are also an integral part of the CDP / PDRR objective of meeting warfighting needs at an affordable cost. Focus is on seven critical areas: avionics, flight systems, manufacturing and producibility, propulsion, structures and materials, supportability, and weapons. Demonstration plans are coordinated with the prime weapon system contractors and results are made available to all program industry participants.

Requirements Definition. This effort leads to Joint Operational Requirements Document completion in FY00; cost/performance trades are key to the process.

克里斯Chris

LockMart JSF Design - X-35

克里斯Chris

Boeing JSF Design - X-35

克里斯Chris

[tr]

Specifications
Function	strike fighter
Contractor	two competing teams: Lockheed-Martin Boeing
Service	U.S. Air Force	U.S. Marine Corps U.K. Royal Navy	U.S. Navy
Variants	Conventional Takeoff and Landing (CTOL)	Short Takeoff and Vertical Landing (STOVL)	Carrier-based (CV)
Unit Cost FY94$	$28M	$35M	$38M
Propulsion	Baseline: Pratt & Whitney F119-PW-100 derivative from F-22 Raptor Alternate Engine: General Electric F120 core
Thrust
Empty Weight	~22,500 lbs		~24,000 lbs
Internal Fuel	15,000 lbs		16,000 lbs
Payload	13,000 lbs		17,000 lbs
Maximum Takeoff Weight	~50,000 lbs
Length	45 feet
Wingspan	36 feet		30 feet
Height
Ceiling
Speed	supersonic
Combat Radius	over 600 nautical miles
Crew	one
Armament
First flight	1999
Date Deployed	2008
Inventory Objectives	U.S. Air Force 2,036 aircraft	U.S. Marine Corps 642 aircraft U.K. Royal Navy 60 aircraft

性能方面請參考F-35，文章來自：Ｘ－３５

克里斯Chris

Q:或許對機種的代號不是很了解者，會認為F-35該不會就是X-35？


A:

X是研發，試驗中機種的代號
F是戰鬥機，A是攻擊機，B是轟炸機等

所以X-35是研發中的飛機，研發試驗成功，正式量產且定位在空優戰鬥機，代號就會改成F-35了，沒特別情況X的應該是早於F的。

因此X-35與F-35是同一機種。

克里斯Chris

JSF聯合戰術打擊機


　1970~80年代起陸續進入美國海空軍服役的F-14/15/16/18等戰鬥機都堪稱是第四代戰鬥機的經典之作，不僅綜合性能極佳，外銷成績也多半輝煌，更在發生在世界各地的無數戰役中獲得亮麗的戰績。然而隨著時代的演進，這些風光一時的機種也逐步邁向暮遲，其水準雖然在1990年代以及21世紀頭幾年尚稱世界一流，但終究將被服役在即的歐洲多種新一代戰機比下去，而機齡日漸老舊也使得這些機群的效率、安全性日漸降低，維護成本攀升。

總而言之，這些叱吒廿世紀後期的優秀戰鬥機即將走到盡頭。美國已經在研發多種新一代戰鬥/攻擊機來取代現役機種，這些新一代機不但採用先進的電子系統、武裝，某些甚至擁有高超的隱形能力；例如接近服役階段的F-22戰鬥機，集最尖端科技於一身，堪稱第五代戰機的極品，這種重型戰鬥機未來將取代廿世紀後期最偉大的空優戰機F-15，成為下一代的空中霸主。緊接著，美國開始進行另一項更具野心的計畫:發展一種具備尖端科技以及匿蹤能力的輕型戰鬥/攻擊機，同時取代空軍、海軍以及陸戰隊現役多種多用途戰鬥/攻擊機，此一計畫便稱為聯合戰術打擊機(Joint Strike Frighter，JSF)。

克里斯Chris

以往美國海、空軍各行其道，各自發展本身所需要的軍機；而曾經出現的幾種海、空軍通用機種最後也未能實現。例如當年企圖成為海、空軍共用機種的F-111最後僅被空軍採用，而美國海軍當年也否定了在輕型戰機競標中獲勝的F-16，轉而採用從F-16的手下敗將YF-17發展而來的F/A-18。但隨著科技的發展，每一代戰鬥機雖然都一直有長足進步，但是造價也隨著進展而節節攀升。為了降低成本，美國國防部便計畫開發一種新的輕型匿蹤超音速多功能戰機，以同一種基本結構發展三種衍生型，分別供空軍、海軍與陸戰隊航空隊使用，這就是1996年脫胎自聯合先進攻擊計畫(Joint Advanced Strike Technology，JAST)的JSF。

JSF總共有三種構型:傳統起降型(CTOL)、艦載型(CV)與短場起飛/垂直降落型(Short Take-off & Vertivcal Landing，STOVL)，三者間必須有70%至80%的整體共通性，更重要的是壽命週期成本必須減低至現役同類機型的65％。其中，JSF的STOVL型將是繼俄羅斯Yak-141戰機之後，全世界第二種具備超音速飛行能力的STOVL機種。

JSF的地位就是美國海、空軍行之有年的戰機「高/低搭配」的低檔部分：高檔部分是精銳強大的大型戰機如美國現役的F-14與F-15，以取得空優為主要任務；而低檔部分則如美國現役的F-16、F/A-18則是較輕型的多功能戰機，造價較為低廉，產量也因此比高檔部分大，除了輔助高檔部分外，尚擔負對地攻擊、偵察等多樣化的任務。


美國空軍新一代的F-22就是昂貴的大型空優戰機，擁有最尖端的電子、匿蹤等科技，造價也高得離譜；而輕型的JSF就是低檔部分，雖然也採用極為先進的科技與概念，但是較前者便宜得多，受到成本限制的程度也遠大於前者。比起負責取得空優的F-22，JSF較注重攻擊地面目標，空戰能力則不如F-22。憑藉著匿蹤能力以及先進的電子系統，JSF在穿越敵方領空打擊地面目標時將擁有更佳的存活率以及戰鬥力。由於開發STOVL技術的經費超越研發匿蹤技術的成本，使得STOVL機型的開發費用居於三種機型之冠。為了降低成本，美國邀請英國加入JSF的STOVL型開發計畫。

克里斯Chris

美國空軍將採購1763架CTOL型以取代F-16與A-10攻擊機，並與高價位的F-22形成高/低搭檔，而在1997年F-22的訂單已經被砍至只剩339架之際，低檔部分的JST CTOL勢必得在美國空軍扮演更為吃重的角色；美國海軍計畫採購480架CV型，與F/A-18E/F一同取代A-6、F-14與F-18C/D等現役機型，成為下一代艦載機主力，並且是開戰後率先進入戰場的高存活率攻擊機種。美國海軍陸戰隊則預計採購609架STOVL型以取代AV-8B。英國皇家空軍將採購90架STOVL型以取代獵鷹GR.7，而英國皇家海軍則採購60架STOVL型以取代海獵鷹FRS.2。為了節省成本，英國皇家海軍放棄對其JSF STOVL型的折疊機翼需求。以上是JSF幾乎確定可以取得的訂單，已經高達3002架。