Sikorsky UH-60 Black Hawk
The Sikorsky UH-60 Black Hawk is a four-blade, twin-engine, medium-lift military utility helicopter manufactured by Sikorsky Aircraft. Sikorsky submitted a design for the United States Army's Utility Tactical Transport Aircraft System 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.
Named after the Native American war chief Black Hawk, the UH-60A entered service with the U.S. 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.
Major variants include the Navy's SH-60 Seahawk, the Air Force's HH-60 Pave Hawk, the Coast Guard's MH-60 Jayhawk and the civilian S-70. In addition to use by U.S. armed forces, the UH-60 family has been exported to several nations and produced under contract in Japan as the Mitsubishi H-60.
Development
Initial requirement
In 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. 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 in January 1972. The RFP also included air transport requirements. Transport within 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 ; run-dry gearboxes; ballistically tolerant, redundant subsystems ; crashworthy crew 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 on 17 October 1974. Prior to the 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
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 an improved gearbox, both from the SH-60B Seahawk. Its external lift capacity increased by up to. The UH-60L also incorporated the SH-60B's automatic flight control system for better flight control with more powerful engines. Production of the L-model began in 1989.
File:CSA-2005-05-05-102937.jpg|thumb|UH-60s equipped with M60 machine guns near An Najaf, Iraq, May 2005.
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, improved rotor blades, and 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. In November 2014, the US military ordered 102 aircraft of various H-60 types, worth $1.3 billion.
Following their use in the operation to kill Osama bin Laden in May 2011, it emerged that the 160th SOAR used a secret version of the UH-60 modified with low-observable technology which enabled it to evade Pakistani radar. Analysis of the tail section, the only remaining part of the aircraft which crashed during the operation, revealed extra blades on the tail rotor and other noise reduction measures, making the craft much quieter than conventional UH-60s. The aircraft appeared to include features like special high-tech materials, harsh angles, and flat surfaces found only in stealth jets. Low observable versions of the Black Hawk have been studied as far back as the mid-1970s.
In September 2012, Sikorsky was awarded a Combat Tempered Platform Demonstration contract to further improve the Black Hawk's durability and survivability. The company is to develop new technologies such as a zero-vibration system, adaptive flight control laws, advanced fire management, a more durable main rotor, full-spectrum crashworthiness, and damage-tolerant airframe; then they are to transition them to the helicopter. Improvements to the Black Hawk are to continue until the Future Vertical Lift program is ready to replace it.
In December 2014, the 101st Airborne Division began testing new resupply equipment called the Enhanced Speed Bag System. Soldiers in the field requiring quick resupply have depended on speed bags filled with items airdropped from a UH-60. However, all systems were ad hoc with bags not made to keep objects secure from impacts, so up to half of the airdropped items would be damaged upon hitting the ground. Started in 2011, the ESBS sought to standardize the airdrop resupply method and keep up to 90 percent of supplies intact. The system includes a hands-free reusable linear brake and expendable speed line and a multipurpose cargo bag. When the bag is deployed, the brake applies friction to the rope, slowing it down enough to keep the bag oriented down on the padded base, a honeycomb and foam kit inside to dissipate energy.
The ESBS better protects helicopter-dropped supplies, and allows the Black Hawk to fly higher above the ground, up from 10 feet, while travelling, limiting exposure to ground fire. Each bag can weigh and up to six can be deployed at once, dropping at. Since supplies can be delivered more accurately and the system can be automatically released on its own, the ESBS can enable autonomous resupply from unmanned helicopters.
Design
The UH-60 features four-blade main and tail rotors, and is powered by two General Electric T700 turboshaft engines. 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. It can carry 11 troops with equipment, lift of cargo internally or of cargo 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 with the helicopter's call sign of "Marine One" when transporting the President of the United States. In air assault operations, it can move a squad of 11 combat troops or reposition a 105 mm M119 howitzer with 30 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.
The UH-60 can be equipped with stub wings at the top of the fuselage to carry fuel tanks or various armaments. The initial stub wing system is called External Stores Support System. It has two pylons on each wing to carry two and two tanks in total. The four fuel tanks and associated lines and valves form the external extended range fuel system. U.S. Army UH-60s have had their ESSS modified into the crashworthy external fuel system configuration, replacing the older tanks with up to four total crashworthy tanks along with self-sealing fuel lines. The ESSS can also carry of armament such as rockets, missiles and gun pods. The ESSS entered service in 1986. However, it was found that the four fuel tanks obstruct the field of fire for the door guns; thus, the external tank system, carrying two fuel tanks on the stub wings, was developed.
The unit cost of the H-60 models varies due to differences in specifications, equipment and quantities. For example, the unit cost of the Army's UH-60L Black Hawk is $5.9 million while the Air Force HH-60G Pave Hawk has a unit cost of $10.2 million.
Operational history
The UH-60 Black Hawk is in service with 35 countries as of 2024.Australia
Australia bought early model UH-60 in the 1980s, and is buying a fleet of newer versions ones in the 2020s:Australia ordered fourteen S-70A-9 Black Hawks in 1986 and an additional twenty-five Black Hawks in 1987. The first US-produced Black Hawk was delivered in 1987 to the Royal Australian Air Force. de Havilland Australia produced thirty-eight Black Hawks under license from Sikorsky in Australia delivering the first in 1988 and the last in 1991. In 1989, the RAAF's fleet of Black Hawks was transferred to the Australian Army. The Black Hawks saw operational service in Cambodia, Papua New Guinea, Indonesia, East Timor and Pakistan.
In April 2009, the then-defence chief Air Chief Marshal Angus Houston, told the government not to deploy Black Hawks to Afghanistan as at the time they "lacked armor and self-defense systems", and despite an upgrade to address this underway, it was more practical to use allies' helicopters. In 2004, the government selected the Multi-Role Helicopter Taipan, a variant of the NHIndustries NH90, to replace the Black Hawk even though the Department of Defence had recommended the S‐70M Black Hawk.
In January 2014, the Army began retiring the fleet of 34 Black Hawks from service and had planned for this to be completed by June 2018. The Chief of Army delayed the retirement of 20 Black Hawks until 2021 to enable the Army to develop a special operations role capable MRH-90. On 10 December 2021, the S-70A-9 Black Hawks were retired from service. On the same day, amid issues with the performance of the MRH-90s the government announced that they would be replaced by UH-60M Black Hawks. In January 2023, the Army announced the acquisition of 40 UH-60Ms with deliveries commencing in 2023.