Pakistan recently received three F-16 Block 52 fighters. These are all-weather aircraft, that are particularly effective at night. These are the first all-weather fighters the Pakistani Air Force has received. Another 15 or these aircraft will be delivered by the end of the year. Pakistan has operated 40 F-16 since the 1990s, but was barred from buying any more after Pakistan revealed that it had nuclear weapons in 1989. That embargo was lifted in 2005 and another 14 F-16s were delivered by 2008.
Pakistan is paying a Turkish firm to upgrade its older F-16s from Block 15 configuration to Block 40 (about halfway to the highest upgrade level for an F-16). 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 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. 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 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 production lines going.
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 anything to enemy warplanes. It was originally designed as a cheaper alternative to the heavier F-15.
The two most advanced versions of the F-16 are in use by foreign air forces. The UAE has 80 "Desert Falcons" (the F-16E) which is optimized for air combat. It is a 22 ton aircraft based on the Block 52 model, but with an AESA (phased array) radar and lots of other additional goodies.
The Israeli F-16I is optimized for bombing. It's a 24 ton, two seat aircraft, and is probably the most capable F-16 model in service. It's basically a modified version of the Block 52, equipped with a more advanced radar (the APG-68X) and the ability to carry Israeli weapons like the Python 4 air-to-air missile and the Popeye 2 air-to-surface missile. Costing $45 million each, the F-16I has an excellent navigation system, which allows it to fly on the deck (a few hundred feet from the ground), without working the pilot to death. The aircraft can do this at night or in any weather. The F-16I can carry enough fuel to hit targets 1,600 kilometers away (meaning Iran is within range). The aircraft uses the latest short and long range air-to-air missiles, as well as smart bombs. Electronic countermeasures are carried, as is a powerful computer system, which records the details of each sortie in great detail. This is a big help for training. The F-16I is basically optimized to deliver smart bombs anywhere, despite dense air defense
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.