『每日軍事武器鑑賞』－ YF-17 ( 即 F/A-18大黃蜂式 藍圖 ）

克里斯Chris

YF-17 Cobra

The McDonnell Douglas F/A-18 Hornet traces its direct ancestry to the Northrop Cobra, a twin engine multimission fighter design developed for the export market in the late 1960s.
In the early 1970s the Air Force pressed for development of a new generation of lightweight fighters-single-seat jet aircraft "optimized" for agility and air combat maneuvering, with high thrust-to-weight ratios (above 1 to 1), and good acceleration. Out of this interest came the so-called "Lightweight Fighter" program. In January 1972, the Lightweight Fighter Program solicited design specifications from several American manufacturers. Participants were told to tailor their specifications toward the goal of developing a true air superiority lightweight fighter. General Dynamics and Northrop were asked to build prototypes, which could be evaluated with no promise of a follow-on production contract. These were to be strictly technology demonstrators. The two contractors were given creative freedom to build their own vision of a lightweight air superiority fighter, with only a limited number of specified performance goals. Northrop's entry was derived from the Cobra design. Northrop produced the twin-engine YF-17 using breakthrough aerodynamic technologies and two high-thrust General Electric YJ101 engines. General Dynamics countered with the compact YF-16, built around a single F100 engine.


Midway down the development path the stakes changed; what had been a technology demonstration became a Department of Defense competition for a new fighter for both the Air Force and Navy, and for allied nations as well. First flight of the YF-17 was in June 1974. By this time, the Air Force had decided to proceed with Air Combat Fighter (ACF) Program, based on flight testing of the YF-16 and YF-17 prototypes. The Navy was also initiating a program to develop a new VFAX in this time period--a strike fighter to replace both the F-4s and A-7s in its carrier air wings.

When the Lightweight Fighter competition was completed early in 1975, both the YF-16 and the YF-17 showed great promise. The two prototypes performed so well, in fact, that both were selected for military service. The Air Force selected the F-16 to be produced for the Tactical Air Command, and the Navy was directed by Congress to base the VFAX on either the YF-16 or YF-17 designs. The Navy, unhappy with the outcome, proceeded independently with a derivative of the YF-17 Cobra, this evolving into the Navy's Northrop F-18 Hornet fighter program. To meet Navy requirements, considerable improvements in areas such as combat radius and radar capability were incorporated, in addition to carrier suitability features. The resulting redesign was extensive and, when the McDonnell Douglas design was selected as winner in 1976, it was assigned the F-18A designation.
After sitting briefly in storage, the two YF-17 prototypes flew again, this time as development aircraft for the proposed F-18. At the request of the Navy, Dryden flew the first YF-17 for base drag studies and to evaluate the maneuvering capability and limitations of the aircraft. NASA pilots-all of whom got at least one flight in the plane-and engineers examined the YF-17's buffet, stability and control, handling qualities, and acceleration characteristics.

克里斯Chris

  (文章來自：大黃蜂演近史）

克里斯Chris

空軍方面雖因造價考量在YF-16與YF17之間選擇YF-16,而海軍則以海上飛行雙發動機較安全之故而選擇YF-17,不過因為洛斯洛普公司從沒有製造艦載機的經驗,而找上到格拉斯公司合作,YF-17經過大幅修改之後重新改型號為F-18,其任務也將取代A-7海盜式攻擊機因此不單性能有所要求機型型號也改成F/A-18。本機1983年進入部隊服役,未來將成為美國海軍航艦的打擊武力主角。

克里斯Chris

YF-16 vs. YF-17

F/A-18的發展史，最早可以回溯到1972年時，美國空軍發展的輕型戰機（Lightweight Fighter，LWF）計畫。當時在參選的諸多團隊中通用動力（General Dynamics）與諾斯洛普（Northrop）獲得最後決選權，分別發展了YF-16與YF-17兩種原型機進行測試，在這計畫中YF-16中選發展成日後大家熟悉的F-16「戰隼式」（Fighting Falcon）戰鬥機，但YF-17「眼鏡蛇式」（Cobra）戰機卻不幸落選。然而在1974年秋天，當美國海軍的空戰戰機（Air Combat Fighter，ACF）計畫開跑時，由於美國國會要求海軍必須自空軍的這兩架競爭者中挑選，兩大集團又再次對壘，不同的是，由於雙方都未曾有承包製造航空母艦艦載機的經驗，諾斯洛普與製造海軍飛機經驗豐富的麥道公司（McDonnell Douglas）合作，以YF-17為藍本開發出海軍版的原型機，並且由該團隊打敗對手所提案、衍生自單引擎的F-16戰機之艦載機版本。

雖然在一開始時，該團隊打算開發出戰鬥機版的F-18與攻擊機版的A-18，來分別取代海軍陸戰隊的F-4與海軍和陸戰隊使用的A-7與A-4攻擊機（1976年，當麥道團隊勝利得到製造授權時，他們其實是授命量產空戰用的F-18A），但是海軍稍後認為這兩種能力的確能夠存在於同一架飛機上面，因此最後的結果是二合一變成一機雙用的F/A-18，同時海軍將使用F/A-18的部隊編號改為「VFA」（戰鬥攻擊中隊）來執行空優與對地攻擊兼顧的雙重任務型態。除了航空母艦起降用的艦載機版本外，諾斯洛普也另外設計減輕重量的陸基版F/A-18L，根據兩家公司的協議，麥道公司負責艦載機版的開發、製造與銷售，諾斯洛普則負責的陸基版的促銷業務。然而尷尬的是，艦載機版F/A-18的外銷市場由於美國軍方採用而大開，反而讓陸基版本毫無商機可言，兩家合作廠商曾一度因此對簿公堂，還好在官方斡旋下解決紛爭，由麥道作為主導廠商執行此計畫，諾斯洛普只負責協助。

克里斯Chris

雖然在外觀上，F/A-18大致保留了F-17的基本構型，像是雙發動機、雙垂直尾翼與大部分的機身架構，但事實上F/A-18無論是在機體結構、航電系統或是動力系統方面，都是徹頭徹尾重新開發的。YF-17原本使用的YJ101渦輪扇葉發動機在提升輸出推力成為F404。為了能夠讓飛行員自己一個人就能順利執行對空與對地的各種任務，導入了先進的數位化概念與玻璃座艙，以陰極射線管（Cathode Ray Tube，CRT）的螢幕取代傳統戰鬥機所使用的複雜指針儀表，採用線傳飛控（Fly-by-Wire）進一步提升飛機的控制性。在設計上也著重飛機的維修性和降低需要的人工，這些革命性的概念對於日後F/A-18大受好評的多功能、好操作之特性，有著關鍵性的幫助。