The Israeli Air Force's (IAF) F-16I Sufa (Thunderstorm), a two seater, is the latest version of the Lockheed Martin F-16. Israel's Peace Marble V foreign military sales program will supply the Israel Air Force (IAF) with 102 two-seat aircraft and is the largest Israeli F-16 acquisition yet. The F-16I is specially designed for Israel, and has been named "Soufa," or "Storm" in Hebrew, by the IAF. The F-16I for Israel is based on current Block 50/52 production aircraft. The F-16I has a 23,600-kilogram [52,000 pound] take-off weight, considerably more than the earlier F-16s in IAF service, and is armed with the AMRAAM air-to-air missile.

The F-16I was developed on the basis of the F-16ES [Enhanced Strategic] single-seat and two-seat, long-range interdictor F-16 proposal. This configuraiton was developed in November 1993 in response to Israeli preference for the F-15I Eagle. The F-16ES featured additional fuel in one 1,136 liter (300 US gallon; 250 Imp gallon) centerline tank and two wing tanks, each 2,271 litre (600 US gallons; 500 Imp gallons), as well as two conformal tanks. The combat radius extended to in excess of 1,000 nautical miles (1,852 km; 1,151 miles). The F-16ES was not purchased at that time, but the conformal tanks were developed as retrofit option for existing F-16s.

The Israeli F-16I Soufa/Sufah (Storm/Thunderstorm), compliments Israel's deterrent strategy by further strengthening the potential threat to carry out retaliatory strikes throughout the Middle East. The extended flight range reportedly allows Israeli forces to attack targets well within Iran without having to refuel. Some offered the interpretation that the 'I' in the F-16I, stands for Iran [actually it stands for Israel]. The bumps over the wing on both sides of the plane are conformal fuel tanks. Use of conformal fuel tanks (CFTs) extends the F-16's effective mission range/loiter time up to 50 percent, depending on the mission profile. CFTs can be used for both air-to-ground and air-to-air missions. They can be easily removed. They also increase weapon payloads by freeing-up additional store stations. The baseline F-16 has a combat radius of 740 nm (1,370 km) with two 2,000-lb bombs and two AIM-9, with 1,040 US gal external tanks.

The Block 52/60 F-16 aircraft procured by Israel, Greece and the UAE have structural, plumbing, and wiring provisions for the Conformal Fuel Tanks (CFT). Attached to the upper surface of the F-16’s fuselage, the tank’s lower surface conform to the aircraft's shape. This arrangement allows the CFTs to be relatively light weight, since nothing is suspended from them. With an empty weight of 900 pounds, tank set holds 450 gallons (about 3,000 pounds) of additional JP-5/8 fuel. A CFT set carries 50 percent more fuel than the centerline external fuel tank, with only 12 percent of the drag. The CFT can dramatically increase the operational radius of the aircraft for long range missions. The aircraft can fly a long range strike mission with full weapon's load, and engage in air combat when external (370 Gal) fuel tanks have been dropped.

The CFT, along with external 370 gallon jetissonable tanks or 600 gallon non-jetissonable external tanks are added with the CFT, provides the F-16 with a 60-70 percent increase in operational radius. At subsonic speeds the CFT have neglible effect on the aircraft agility, thought the drag increases in proportion to speed at supersonic speeds. The aircraft fitted with CFT retain nearly the full handling qualities, flight limits, and signature.

The CFT set can be fitted or removed in less than two hours. The tanks are are built under the Peace Marble V program by IAI as a sole source to Lockheed Martin's specification.

Lockheed Martin began F-16 flight demonstration of an initial CFT shape in 1994 to investigate performance and handling quality characteristics. Subsequent wind tunnel testing led to the current external lines, which were initially validated in flight testing of high angle-of-attack handling characteristics at Edwards AFB, CA. Lockheed Martin Aeronautics Company completed the first phase of flight testing of its new conformal fuel tanks (CFTs) for its F-16 multirole fighter in September 2001. Flight testing with aerodynamic shapes was conducted on an F-16C at Eglin Air Force Base, FL, from March through August. A total of 24 test flights and 65 flight test hours were accomplished, and testing involved loads, flutter, and stability and control.

There are conflicting reports concerning the F-16I combat radius, but the most reliable source reports a combat radius of 2,100 km, on par with the F-15I. The Israeli military would not disclose the exact range of the jet, but one senior air force officer said, "it can reach the capitals of all the countries in the region." One report says that "it has an 820 km non-refueling radius of operation, sufficient to reach both Libya and Iran" -- but a glance at a map reveals that 820 kilometers from Israel is short of Baghdad, and far short of the 1,500 kilometers need to reach Tehran. One report suggest that the F-16I has an unrefueled combat strike radius of 1,640 kilometers without refueling. Another report relates that the external fuel capacity in conformal fuel tanks increases the aircraft range to 800 miles (1,500 km). One published reports states that the external fuel tanks above the central fuselage, extend the range of the jet and the reach of the Israeli air force by 25 percent.
http://www.globalsecurity.org/milita...rael/f-16i.htm