Wikileaks documents have recently revealed that the U.S. did not believe that Pakistan, even with more American F-16 fighters (and upgrades to older Pakistani fighters) would significantly change air superiority situation along the Indian border. India already has more high-tech fighters than Pakistan, and the additional aircraft from the U.S. would only prolong the air battle with India by a few days. That, it was hoped, would give the U.S. (and other major powers) enough time to arrange a peace deal and avoid a nuclear war between Pakistan and India. In effect, the American diplomats had concluded that the Pakistanis were delusional if they thought they were anywhere near military parity with neighboring India. But diplomats must lie for their country, so they agreed with Pakistani military claims, and offered more F-16s.
After September 11, 2001, the United States resumed shipping F-16 fighters to Pakistan. These shipments had been halted for over a decade because Pakistan refused to stop working on developing nuclear weapons. The shipments resumed because America needed Pakistani help in dealing with al Qaeda and the Taliban in Afghanistan. Pakistan thought the additional F-16s, and upgrading of existing ones, would even up the odds in any future air war with India. But these Wikileaks documents (secret messages between American diplomats), ensure that the Pakistanis (and everyone else) now know what the U.S. really thought of Pakistani military abilities. The Pakistanis also now know that this is what the Indians were told, and apparently the Indians agreed with the assessment, but still made a lot of noise about this American aid to Pakistan (to placate the Indian public).
Meanwhile, Pakistan is upgrading 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, was able to seek the best price for this work. They selected a Turkish firm for this, as the Turks 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.
The Turks also work cheaper, and 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 single engine MiG-21s, and the U.S over 5,000 twin engine F-4s, but since then, warplane production has plummeted about 90 percent. Yet, 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 three 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, not counting some occasional threatening maneuvers against Soviet fighters along the Afghan border during the 1980s.