In an effort to upgrade its attack helicopter fleet, the Israel Air Force is conducting flight tests with a new version of the Black Hawk utility helicopter that has been equipped with offensive air-to-surface missile launchers. Israel has several dozen Black Hawk helicopters - called Yanshuf - which it began receiving in the 1990s. Made by Sikorsky Aircraft Corporation, the helicopter was designed in the 1970s as a utility tactical transport aircraft for the United States Air Force. The helicopter can carry a squad of a dozen troops with equipment or alternatively carry over one ton of equipment. The US has a variant of the Black Hawk that is used for special operations and is equipped with Hellfire missiles, an automatic cannon as well as 70mm rockets. The arming of the Black Hawk is being done jointly by the IAF, Sikorsky and several local defense contractors. One of the helicopters has already successfully test-fired an air-to-surface missile. The helicopter has also been equipped with a rapid-fire cannon that sits under the aircraft's belly. The IAF, sources said, does not plan at this stage to equip all of its Black Hawk helicopters with offensive capabilities but is conducting the tests to see if the possibility exists should a decision to do so be made in the future. At the same time, the IAF is close to finalizing negotiations with Boeing to upgrade at least six additional Apache attack helicopters in an effort to bolster the air support the IAF is able to provide ground forces in future operations in Lebanon and the Gaza Strip. The plan is to upgrade several of its old "A" model Apache helicopters to the "D" model Longbow version with the above-rotor advanced radar system, which enables the helicopter to share targeting data with other Longbows. According to foreign reports, Israel has 37 "A" model Apaches and 11 Longbows. IAF plans are to establish a second squadron of Apache Longbows within the coming decade. Three Apache helicopters - including one Longbow - were lost during the Second Lebanon War. In one incident, two Apaches collided in midair. In the other case, the Longbow crashed due to a malfunction in the rotor.