The Sikorsky UH-60 Black Hawk is a twin-engine medium-lift multipurpose helicopter manufactured by Sikorsky Aircraft. Sikorsky submitted the S-70 design for the United States Army's Utility Tactical Transport Aircraft System (UTTAS) competition in 1972. The Army designated the prototype as the YUH-60A and selected the Black Hawk as the program winner in 1976, following a fly-off competition with Boeing Vertol. YUH-61 .The UH-60A entered Army service in 1979, to replace the legendary Bell UH-1 Iroquois as the Army's tactical transport helicopter. This was followed by electronic warfare and the special operations variant of the Black Hawk. Improved utility variants of the UH-60L and UH-60M have also been developed. A modified version has also been developed for the Navy (SH-60 Seahawk), which is used in maritime operations such as amphibious landing, marine special operations, maritime reconnaissance and anti-submarine warfare, the Air Force, and the Coast Guard. A civilian version is also available under the name Sikorsky S-70. In addition to use by the US Armed Forces, the UH-60 family has been exported to several countries. Black Hawks have served in combat during conflicts in Grenada, Panama, Iraq, Somalia, the Balkans, Afghanistan and other areas of the Middle East. This helicopter became famous in popular culture after appearing in the war film Black Hawk Down.