While the two aircraft are greatly similar, areas of difference include the hydraulic systems and internal fuel arrangements.

To date, large numbers of J-7s remain in service with multiple export customers,[3][4] with PLAAF retiring the fleet in 2023.

[5] In the 1950s and early 1960s, the Soviet Union shared a large proportion of its conventional weapons technology with its neighbor, China.

A delegation headed by General Liu Yalou, the commander-in-chief of the People's Liberation Army Air Force (PLAAF) and himself a Soviet military academy graduate, was dispatched to Moscow immediately; the Chinese delegation was given three days to visit the MiG-21's production facility, which was previously off-limits to foreigners.

[citation needed][8] However, given the state of political relations between the two countries, the Chinese were not optimistic about gaining the technology, and allegedly made preparations to reverse engineer the aircraft.

[6] Russian sources state that several complete MiG-21s were sent to China, flown by Soviet pilots, while MiG-21Fs in kit form was also sent along with parts and technical documents.

The re-engineering effort was largely successful, as the Chinese-built J-7 showed only minor differences in design and performance from the original MiG-21.

However, mass production efforts were severely hindered by an unexpected social and economic problem—the Cultural Revolution—that resulted in poor initial quality and slow progress.

China later developed the Shenyang J-8 based both on the expertise gained by the program, and by utilizing the incomplete technical information acquired from the Soviet Ye-152 developmental jet.

[18] On September 20, 2018, two Nigerian F-7Ni aircraft crashed into Katamkpehir, Abuja, killing one pilot after a mid-air collision during a rehearsal of an aerial display for the 58th anniversary of Nigeria's independence.

[23] Their only deployment in the DR Congo took place in January 2001, when four aircraft were to participate in the burial ceremony for the assassinated president, Laurent-Désiré Kabila.

[citation needed] In June 2021, four J-7s participated in a combat drill conducted near Taiwan's air defense identification zone.

According to the US Air Force China Aerospace Studies Institute, the retirement of J-7 marked the PLAAF's transition to a fleet composed of only fourth-generation and fifth-generation aircraft.

A series of upgrades were allegedly performed by a combination of Chinese and Israeli enterprises; although confirmed details on the arrangements have remained sparse, changes reportedly include the adoption of various Israeli-built missiles.

[30][29] During the 1980s, Iran procured a number of F-7s, despite Chinese officials issuing denials of directly supplying military equipment to the country at that time.

This is caused by the limited availability of spare parts, despite efforts by domestic industries to fill in, but also by the age of the airframes, which have accumulated excessive numbers of flight hours.

One tells the story of an Islamic Republic of Iran Air Force strike on the Iraqi nuclear reactor at Osirak on 30 September 1980.

During the 1980s, Pakistan launched Project Sabre II in an effort to increase the effectiveness of its F-7 fleet by redesigning and upgrading the airframe.

With western countries refusing to sell attack aircraft, the Government of Sri Lanka approached China for the purchase of several Nanchang Q-5s, which had the range and payload capacity needed by the SLAF, and was already used by Pakistan and Bangladesh.

Due to pressure from the west, China agreed to sell a small number of F-7BS fighters which allowed the SLAF to restore its capabilities that were lost a decade back.

[41][42] The SLAF has repeatedly deployed its F-7BS to conduct ground-attack missions against the Liberation Tigers of Tamil Eelam (LTTE).

According to the Sri Lankan government, the rebel-flown aircraft was shot down by the chasing F-7G using an air-to-air missile, as it was returning to Mullaitivu after a bombing run against Vavuniya Airport.