The UH-60 Black Hawk is a four-bladed, twin-engine, medium-lift utility 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 winner of the program in 1976, after a fly-off competition with the Boeing Vertol YUH-61.The UH-60A entered service with the Army in 1979, to replace the Bell UH-1 Iroquois as the Army's tactical transport helicopter. This was followed by the fielding of electronic warfare and special operations variants of the Black Hawk. Improved UH-60L and UH-60M utility variants have also been developed. Modified versions have also been developed for the U.S. Navy and U.S. Air Force. In addition to U.S. Army use, the UH-60 family has been exported to several nations. Black Hawks have served in combat during conflicts in Grenada, Panama, Iraq, Somalia, the Balkans, Afghanistan, and other areas in the Middle East.
Development[edit] Initial requirementIn the late 1960s, the United States Army began forming requirements for a helicopter to replace the UH-1 Iroquois, and designated the program as the Utility Tactical Transport Aircraft System (UTTAS). The Army also initiated the development of a new, common turbine engine for its helicopters that would become the General Electric T700. Based on experience in Vietnam, the Army required significant performance, survivability and reliability improvements from both UTTAS and the new powerplant. The Army released its UTTAS request for proposals (RFP) in January 1972. The RFP also included air transport requirements. Transport aboard the C-130 limited the UTTAS cabin height and length.
The UTTAS requirements for improved reliability, survivability and lower life-cycle costs resulted in features such as dual-engines with improved hot and high altitude performance, and a modular design (reduced maintenance footprint); run-dry gearboxes; ballistically tolerant, redundant subsystems (hydraulic, electrical and flight controls); crashworthy crew (armored) and troop seats; dual-stage oleo main landing gear; ballistically tolerant, crashworthy main structure; quieter, more robust main and tail rotor systems; and a ballistically tolerant, crashworthy fuel system.
Four prototypes were constructed, with the first YUH-60A flying in October 1974. Prior to delivery of the prototypes to the US Army, a preliminary evaluation was conducted in November 1975 to ensure the aircraft could be operated safely during all testing. Three of the prototypes were delivered to the Army in March 1976, for evaluation against the rival Boeing-Vertol design, the YUH-61A, and one was kept by Sikorsky for internal research. The Army selected the UH-60 for production in December 1976. Deliveries of the UH-60A to the Army began in October 1978 and the helicopter entered service in June 1979.
Upgrades and variations
UH-60s equipped with M60 machine guns near An Najaf, Iraq in May 2005.After entering service, the helicopter was modified for new missions and roles, including mine laying and medical evacuation. An EH-60 variant was developed to conduct electronic warfare and special operations aviation developed the MH-60 variant to support its missions.
Due to weight increases from the addition of mission equipment and other changes, the Army ordered the improved UH-60L in 1987. The new model incorporated all of the modifications made to the UH-60A fleet as standard design features. The UH-60L also featured more power and lifting capability with upgraded T700-GE-701C engines and a stronger gearbox, both developed for the SH-60B Seahawk. Its external lift capacity increased by 1,000 lb (450 kg) to 9,000 lb (4,100 kg). The UH-60L also incorporated the automatic flight control system (AFCS) from the SH-60 for better flight control due to handling issues with the more powerful engines. Production of the L-model began in 1989.
Development of the next improved variant, the UH-60M, was approved in 2001, to extend the service life of the UH-60 design into the 2020s. The UH-60M incorporates upgraded T700-GE-701D engines and improved rotor blades. It also features state of the art electronic instrumentation, flight controls and aircraft navigation control. After the U.S. DoD approved low-rate initial production of the new variant,manufacturing began in 2006, with the first of 22 new UH-60Ms delivered in July 2006. After an initial operational evaluation, the Army approved full-rate production and a five-year contract for 1,227 helicopters in December 2007. By March 2009, 100 UH-60M helicopters had been delivered to the Army.[15]
In the 1 May 2011 operation that killed Osama bin Laden, it emerged that the 160th Special Operations Aviation Regiment, which operated the helicopters during the raid, used a heavily modified version of the UH-60. Features apparently include a modified tail section with extra blades on the tail rotor and other additions which significantly lower noise levels from that of conventional UH-60s. It also had low-observable technology similar to that of F-117 that enabled it to evade Pakistan Air Force radars. The aircraft seemed to include features like special high-tech materials, harsh angles, and flat surfaces, found only on sophisticated stealth jets. This came to light only when one of the helicopters used in the operation crashed and was subsequently destroyed except for its tail section.[16][17][Nb 1]
Design
UH-60A Black Hawk parked on flight lineThe UH-60 features a four-blade main and tail rotors and is powered by two General Electric T700 turboshaft engines.[19] The main rotor is fully articulated and has elastomeric bearings in the rotor head. The tail rotor is canted and features a rigid crossbeam. The helicopter has a long, low profile shape to meet the Army's requirement for transporting aboard a C-130 Hercules, with some disassembly.[19] It can carry 11 troops with equipment, lift 2,600 lb (1,170 kg) of cargo internally or 9,000 lb (4,050 kg) of cargo (for UH-60L/M) externally by sling.
The Black Hawk helicopter series can perform a wide array of missions, including the tactical transport of troops, electronic warfare, and aeromedical evacuation. A VIP version known as the VH-60N is used to transport important government officials (e.g., Congress, Executive departments) with the helicopter's call sign of "Marine One" when transporting the President of the United States.[21] In air assault operations it can move a squad of 11 combat troops or reposition a 105 mm M102 howitzer with thirty rounds ammunition, and a four-man crew in a single lift.The Black Hawk is equipped with advanced avionics and electronics for increased survivability and capability, such as the Global Positioning System.
UH-60A Black Hawks over Port Salinas during the invasion of Grenada, 1983. The conflict saw the first use of the UH-60.The UH-60 can be equipped with stub wings at top of fuselage to carry fuel tanks or various armaments. The initial stub wing system is called External Stores Support System (ESSS). It has two pylons on each wing to carry two 230 US gal (870 L) and two 450 US gal (1,700 L) tanks in total. The four fuel tanks and associated lines and valves form the external extended range fuel system (ERFS).[23] The ESSS can also carry 10,000 lb (4,500 kg) of armament such as rockets, missile and gun pods.[10][24] The ESSS entered service in 1986. However it was found that with four fuel tanks it would obstruct the firing field of the door guns. To alleviate the issue, the external tank system (ETS) with unswept stub wings to carry two fuel tanks was developed.
The unit cost varies with the version due to the varying specifications, equipment and quantities. For example, the unit cost of the Army's UH-60L Black Hawk is $5.9 million while the unit cost of the Air Force MH-60G Pave Hawk is $10.2 million.
VariantsThe UH-60 comes in many variants, and many different modifications. The U.S. Army variants can be fitted with the stub wings to carry additional fuel tanks or weapons. Variants may have different capabilities and their respective equipment in order to fulfill different roles.
Utility variants
UH-60L from B Company ("Lancers"), 5th Battalion, 101st Aviation Regiment, on an air assault mission in Iraq
US Army UH-60A MEDEVAC evacuating simulated casualties during a training exerciseYUH-60A: The initial test and evaluation version. First flight on 17 October 1974; three built.
UH-60A Black Hawk: Original U.S. Army version, carrying a crew of four and up to 11 equipped troops. Equipped with T700-GE-700 engines.[59] Produced 1977–1989.
UH-60C Black Hawk: Modified version for Command and control (C2) missions.
CH-60E: Proposed troop transport variant for the US Marine Corps.
UH-60L Black Hawk: UH-60A with upgraded T700-GE-701C engines, improved durability gearbox, and updated flight control system.[10] Produced 1989–2007.[61] UH-60Ls are also being equipped with the GE T700-GE-701D engine.[citation needed]
UH-60M Black Hawk: Improved design wide chord rotor blades, T700-GE-701D engines (max 2,000 shp/1,500 kW each), improved durability gearbox, Integrated Vehicle Management Systems (IVHMS) computer, and the Common Avionics Architecture System (CAAS) flight instrument suite. Production began in 2006. Planned to replace older U.S. Army UH-60s.
UH-60M Upgrade Black Hawk: UH-60M with fly-by-wire system and Common Avionics Architecture System (CAAS) flight system. Flight testing began in August 2008.
[edit] Special purposeEH-60A Black Hawk: UH-60A with modified electrical system and stations for two electronic systems mission operators. All examples of type have been converted back to standard UH-60A configuration.
YEH-60B Black Hawk: UH-60A modified for special radar and avionics installations, prototype for stand-off target acquisition system.EH-60C Black Hawk: UH-60A modified with special electronics equipment and external antenna. (All examples of type have been taken back to standard UH-60A configuration.)
EUH-60L (no official name assigned): UH-60L modified with additional mission electronic equipment for Army Airborne C2.
EH-60L Black Hawk: EH-60A with major mission equipment upgrade.
UH-60Q Black Hawk: UH-60A modified for medical evacuation. The UH-60Q is named DUSTOFF for "dedicated unhesitating service to our fighting forces".
HH-60L (no official name assigned): UH-60L extensively modified with medical mission equipment.Components include an external rescue hoist, integrated patient configuration system, environmental control system, on-board oxygen system (OBOGS), and crashworthy ambulatory seats.
HH-60M Black Hawk: US Army variant. UH-60M with medical mission equipment (medevac version).[59][68] Also has no gunner's windows, and includes a nose mounted FLIR.[citation needed]
MH-60L Direct Action Penetrator (DAP)MH-60A Black Hawk: US Army variant. 30 UH-60As modified with additional avionics, night vision capable cockpit, FLIR, M134 door guns, internal axillary fuel tanks and other Special Operations mission equipment in early 1980s. Equipped with T700-GE-701 engines.[59] Variant was used by the 160th Special Operations Aviation Regiment. The MH-60As were replaced by MH-60Ls beginning in the early 1990s and passed to the Air National Guard.
MH-60K Black Hawk: US Army variant. Special operations modification first ordered in 1988 for use by the 160th Special Operations Aviation Regiment ("Night Stalkers"). Equipped with the in-flight refueling probe, and T700-GE-701C engines. More advanced than MH-60L, the K-model also includes an integrated avionics system (glass cockpit), AN/APQ-174B terrain-following radar, color weather map generator, improved weapons capability, and various defensive systems.
MH-60L Black Hawk: US Army variant. Special operations modification, used by the 160th Special Operations Aviation Regiment ("Night Stalkers"), based on the UH-60L with T700-701C engines. It was developed as an interim version in the late 1980s pending fielding of the MH-60K. Equipped with many of the systems used on MH-60K, including FLIR, terrain-following radar, color weather map generator, auxiliary fuel system,[75] and laser rangefinder/designator. 37 MH-60Ls were built and some 10 had received a in-flight refueling probe by 2003.
MH-60L Direct Action Penetrator (DAP): US Army variant. Special operations modification of the baseline MH-60L, operated by the 160th Special Operations Aviation Regiment.[76] The DAP is equipped with ESSS or ETS stub wings, each capable of carrying a M230 Chain Gun 30 mm automatic cannon, rocket pods, and various other armaments. M134D miniguns are used as door guns.
MH-60M Black Hawk: US Army variant. Special operations version of UH-60M. It will feature the Rockwell Collins Common Avionics Architecture System (CAAS) glass cockpit and more powerful YT706-GE-700 engines.
MH-60 Black Hawk stealth helicopter: One of two specially modified MH-60s used in the raid on Osama bin Laden's hideout in Pakistan on 1 May 2011 was damaged in a hard landing, and was subsequently destroyed by US forces. Subsequent reports state that the Blackhawk destroyed was a previously unconfirmed, but rumored, modification of the design with reduced noise signature and stealth technology.The modifications are said to add several hundred pounds to the base helicopter including edge alignment panels, special coatings and anti-radar treatments for the windshields.
VH-60N used to transport the President of the United StatesUH-60A RASCAL: NASA-modified version for the Rotorcraft-Aircrew Systems Concepts Airborne Laboratory: $US25M program for the study of helicopter maneuverability in three programs, Superaugmented Controls for Agile Maneuvering Performance (SCAMP), Automated Nap-of-the-Earth (ANOE) and Rotorcraft Agility and Pilotage Improvement Demonstration (RAPID).
VH-60D Nighthawk: USMC variant. VIP-configured HH-60D, used for Presidential transport. T700-GE-401C engines. Variant was later redesignated VH-60N.
VH-60N Whitehawk: USMC variant. Modified UH-60A with some features from the SH-60B/F Seahawks. Used for Presidential and VIP transport. It entered service in 1988 and nine were delivered.
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