Monday, July 21, 2008

Sikorsky S-70 International Black Hawk

Sikorsky S-70 International Black Hawk July 21, 2008: The Sikorsky S-70 family of helicopters, designated the H-60 in US military use, is the most popular US military helicopter next to the Bell UH-1 Huey. Variants of the S-70, with names like Seahawk, Jayhawk and Pave Hawk are used by the US Navy, Coast Guard and Air Force and are used around the world. They serve in a wide range of transport and support roles, including search and rescue, antisubmarine and maritime surveillance, and special tasks. The Customs Service and the US Drug Enforcement Agency (DEA) also use the aircraft. It is the most popular U.S. military helicopter produced in the last two decades, with more than 2,400 in use. The Sikorsky Model S-70 was developed in response to the Army's 1972 request for a Utility Tactical Transport System (UTTAS) helicopter. The UTTAS design criteria were based upon U.S. experience during Vietnam. In particular, the Army wanted a helicopter with crew survivability features and engines, rotors, and transmission designed to be better capable of taking damage than the Huey. Sikorsky equipped the S-70 with a crashworthy cabin "box," an armor-plated cockpit, self-sealing fuel tanks, and wheeled landing gear that could absorb heavy vertical impacts. The S-70, unlike most Hueys, has two engines, either of which can keep the helicopter in the air if the other fails. It also has widely-separated redundant electronic and hydraulic systems. It has four main rotor blades and a tail rotor that is tilted at an angle and therefore provides some additional lift. One of the most distinctive aspects of the S-70 is its shape. Unlike the Huey, it is long and low-set. This design was dictated by the requirement that the helicopter be able to fit inside a C-130 Hercules cargo plane without removing the rotors. Two of the craft had to be capable of fitting inside a C-141 and six within a C-5 Galaxy. The low ceiling of these aircraft required a helicopter that was wider and squatter than a Huey. The US military versions of the H-60 helicopter have been expanded into a series of S-70 derivatives specifically focused on the international market. A growing number of international customers rely on the S-70 for their Utility Transport and Maritime requirements. The legendary ruggedness and survivability of the BLACK HAWK, combined with its multi-mission flexibility, have made the S-70 the world's standard medium utility helicopter. Sikorsky has marketed the S-70 to various militaries around the world. Spain, Japan, Australia, Greece, Taiwan, Thailand and Turkey fly naval variants. Army variants are flown by the Philippines, China, Taiwan, Jordan, Bahrain, Brunei, Columbia, Australia, Saudi Arabia, Turkey, South Korea, Japan, Egypt, Mexico, Morocco, Hong Kong, Argentina, Israel, the United Kingdom, Mexico, Malaysia, Kuwait and Czechoslovakia, and others. Japan produces both versions under license, and Turkey and South Korea co-produce them as well. Civilian versions are also in operation, usually for VIP transport or law enforcement purposes. Although the Black Hawk is a highly capable successor to the Huey, it has drawbacks that made it unsuccessful commercially. It is more expensive than the Huey and more complicated. Iinitially it ecoountered avionics problems when German power lines affected its electronics. The two engines require more maintenance than the Huey's single engine. For some civilian roles and some foreign militaries, the S-70 is larger and more sophisticated than needed.

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