| F-7S Sabre II | |
|---|---|
| General information | |
| Type | Multi-role combat aircraft |
| Manufacturer | Pakistan Aeronautical Complex |
| Designer | Pakistan Aeronautical Complex |
| Status | Cancelled |
| Primary user | Pakistan Air Force (PAF) |
| History | |
| Introduction date | 1987 |
| Developed from | Chengdu F-7M |
| External images | |
|---|---|
 Models of the Sabre II, inPAF markings, and the Chengdu F-7 published in September 1987.[1] | |
| The F-7 Sabre II and the Super 7. |
Project Sabre II was thePakistan Air Force's program to develop a feasible andlow-costmultirolecombat jet based on an existing design—theChengdu F-7 Skybolt, aChinese variant of theMiG–21.[2][3][4] The Pakistan Air Force (PAF) initiated Project Sabre II in 1987, hiring theAmerican aerospace firmGrumman, to provide crucial expertise to refine the baselineaircraft design along with specialists from the PAF and theChinese People's Liberation Army Air Force (PLAAF).[5]
After studying the Sabre II concept with Grumman, the PAF terminated the program as unfeasible on economic grounds. Grumman withdrew from the project aftersanctions were imposed by theUnited States onChina after Beijing's suppression of theTiananmen Square protests of 1989.[6][7]An embargo on military aid to Pakistan imposed by theUnited States further hampered the Sabre II development effort in the 1990s.[8][self-published source] In 1995, Pakistan and China began a collaboration which led to the successfulJF-17 Thunder program.[4][5][9]
In 1982, theIndian Air Force (IAF) procured theMiG-29 Fulcrum from theSoviet Union to modernize its fighter aircraft fleet. As a result, thePakistan Air Force (PAF) began looking for new technology to replace its aging fighters. By 1984, the PAF'sF-7P (Chengdu F-7) fighters were equipped with western electronic systems. The PAF began developing an improved version of theF-7M to replace its large fleet ofF-6 fighters.[2][3][4]
The Pakistan Air Force started looking for a new fighter to replace their large fleet ofShenyang F-6 fighters,[10] as they approached the end of their service lives in the late 1980s.[11] After showing interest in the F-7M, theAir HQ of thePakistan Air Force initiated Project Sabre–II to the develop a low-costmultirole fighter jet on the model of the F-7M.[10]
In January 1987, thePakistan Air Force commissionedNew York-basedGrumman Aerospace to conduct studies and assess the feasibility of the Sabre II design concept with Pakistani aerial specialists and the ChineseChengdu Aircraft corporation. After five to seven months, the group concluded that the financial risks caused by very high project costs, and the availability of more cost-effective options outweighed the potential benefits from technology transfer from the US to thePakistan Aeronautical Complex, increasing its experience and technical knowledge.[12]
Grumman, the Pakistan Air Force and the ChinesePeople's Liberation Army Air Force (PLAAF) created the Sabre II concept by radically upgrading theF-7M.[13] Changes included upgrades to itsavionics suite, radar system and engine, and a redesigned forward fuselage. The PAF stated that the Sabre II would replace around 150F-6s in combat service. A picture showed that the F-7's nose inlet had been replaced with a solid nose radome and a new pair of air inlets were mounted on the sides of the fuselage under the cockpit.[14]
Under Project Sabre II and the ChineseSuper-7 project, the F-7 airframe was redesigned with angled air intakes on the sides of thefuselage so a solidradome nose could house radar and other avionics fromNorthrop's F-20 "Tigershark" fighter. The Chinese WP-7turbojet engine was to be replaced with a modernturbofan engine, either theGE F404 orPW1120, to improve performance. The resulting aircraft, designated F-7M Sabre-II,[15] would have looked much like theGuizhou JL-9 (or FTC-2000)jet trainer / fighter aircraft.
Pratt & Whitney'sPW1216, an afterburning derivative of theJ52-P-409 turbojet producing 16,000 pounds-force (71 kN) of thrust, was also proposed as the Sabre II's engine. Its afterburner was designed in China.[16][17] Fitting the APG-66 radar was also planned.[18]
As the Soviet Union waswithdrawing from neighboring Afghanistan, American interest in Pakistan lessened. ThePAF terminated the Sabre II project afterGrumman's warning that it was financially risky and less feasible than other options. Worsening of theUS–Chinese relations after Beijing's suppression of theTiananmen Square student protests also hurt the project, as U.S.sanctions preventedtransfer of American technology to China. Grumman Aerospace withdrew from the project shortly thereafter.
At the same time, the US Congress imposed anembargo on economic and military exports to Pakistan when Congressional leaders became aware of Pakistan'satomic bomb program. A panic ensued among thePakistani military, as its nuclear bomb program impacted the Super-7 project. The US government tolerated Pakistan's nuclear program during the 1980s due to a desire for the country's cooperation in defeating the USSR in theSoviet–Afghan War. Once the Soviet forces retreated, Pakistani cooperation was no longer required and military and economic sanctions were imposed on Pakistan under thePressler amendment in 1990. This preventedF-16 aircraft already paid for by the PAF during the Afghan war from being delivered. Efforts by the PAF to find a replacement failed (seePakistan Air Force#1990–2001: U.S. arms embargo).
ThePakistan Air Force decided on a much less expensive solution for replacement of theF-6, theF-7P Skybolt, an upgraded version of the F-7M Airguard.[19] The F-7P fleet was to be supported by a fleet of over 100 advancedF-16s from the United States, 40 of which had been delivered during the 1980s.[19] The PAF launched a secretive project,ROSE, to procure as many second-handDassault Mirages as possible and upgrade their electronic systems. In March 1990 it was reported that after being rejected by the PAF, Sabre II had been superseded by the Super 7 and China was considering continuing its development.[3] TheAmerican arms embargo had forced the PAF to come up with innovative solutions to keep all its combat infrastructure operational.[19]
The PAF hired Russia'sMikoyan Group as consultants, and design studies for the project began at thePakistan Aeronautical Complex.[19] In 1995, the Pakistan Air Force decided to resume the program and quickly reached out to China.Memoranda of Understanding were reached between both countries towards developing new aircraft to fill the role of the Super 7.[12] This led to the successful development of theJF-17 Thunder, introduced in 2003.[5][9]