Despite an aggressive sales pitch from an American firm, Pakistan decided to go with a less expensive Turkish company to upgrade its older F-16s from Block 15 configuration to Block 40 (about halfway to the highest upgrade level for an F-16). This is called the MLU (Mid-Life Upgrade). Now that the U.S. has lifted its arms embargo on Pakistan, there are many firms competing for all the work needed to update older American weapons still used by Pakistan. The Turks, however, have long had good trade relations with Pakistan, and have also developed, with the help of the U.S. and Israel, a growing aircraft maintenance and upgrade industry. As a member of NATO, the Turkish aircraft upgrade firms had to meet a series of work quality standards, just so they could upgrade Turkish equipment.
But the Turks work cheaper, and the combination of proven quality and low price led to landing the Pakistani contract. Most of the F-16 work will be done in Pakistan, using Turkish engineers and technicians supervising some local workers, and using largely imported (from Turkey and elsewhere) components. Turkey has long maintained one the largest F-16 fleets outside of the United States. The Turks currently have 240 F-16s, and more are on the way. Pakistan has about fifty flyable F-16s, with 18 more on order.
The F-16 is the most numerous post-Cold War jet fighter, with over 4,200 built, and still in production. During The Cold War, Russia built over 10,000 MiG-21s, and the U.S over 5,000 F-4s, but since then, warplane production has plummeted about 90 percent. But since the end of the Cold War, the F-16 has been popular enough to keep the orders coming.
The U.S. F-16 is one of the most modified jet fighters in service. While most are still called the F-16C, there are actually six major mods, identified by block number (32, 40, 42, 50, 52, 60), plus the Israeli F-16I, which is a major modification of the Block 52. Another special version (the Block 60), for the UAE (United Arab Emirates) is called the F-16E. The F-16D is a two seat trainer version of F-16Cs. The various block mods included a large variety of new components (five engines, four sets of avionics, five generations of electronic warfare gear, five radars and many other mechanical, software, cockpit and electrical mods.)
The F-16 can also function as a bomber and ground attack aircraft, although not as effectively as the air force folks would have you believe. It can carry four tons of bombs. In air-to-air combat, it has shot down 69 aircraft so far, without losing to enemy warplanes. It was originally designed as a cheaper alternative to the heavier F-15.
For the last two years, Pakistani F-16s have been heavily used in the tribal territories, along the Afghan border, dropping smart and dumb bombs, and giving the pilots experience using targeting pods. This is the first combat experience the Pakistani F-16s have received.