The Sikorsky 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, Air Force, and Coast Guard. 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

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 (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.[3] 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

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.
 

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 highly 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 lowered 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. 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 (CTPD) contract to further improve the Black Hawk's durability and survivability. Sikorsky 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 transition them to the helicopter. Improvements to the Black Hawk are to continue in preparation for the Joint Multi-role Helicopter competition that will replace it.
 

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 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. 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.
 

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). The ESSS can also carry 10,000 lb (4,500 kg) of armament such as rockets, missile and gun pods.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 HH-60G Pave Hawk is $10.2 million.
 

Operational history

United States

The UH-60 entered service with the U.S. Army's 101st Combat Aviation Brigade of the 101st Airborne Division in June 1979.The U.S. military first used the UH-60 in combat during the invasion of Grenada in 1983, and again in the invasion of Panama in 1989. During the Gulf War in 1991, the UH-60 participated in the largest air assault mission in U.S. Army history with over 300 helicopters involved. Two UH-60s (89-26214 and 78-23015) were shot down, both on 27 February 1991, while performing Combat Search and Rescue of other downed aircrews, an F-16C pilot and the crew of a MEDEVAC UH-1H that were shot down earlier that day.
 

In 1993, Black Hawks featured prominently in the assault on Mogadishu in Somalia. Black Hawks also saw action in the Balkans and Haiti in the 1990s. Army UH-60s and other helicopters conducted many air assault and other support missions during the 2003 invasion of Iraq. The UH-60 has continued to serve in operations in Afghanistan and Iraq.
 

The U.S. Border Patrol uses the UH-60 in its operations specifically along the southwest border. The Blackhawk has been used by the Border Patrol to interdict the illegal entry of aliens into the U.S. and the incursion of dangerous individuals. Additionally, the Border Patrol regularly uses the UH-60 in search and rescue operations.
 

Highly modified H-60s were employed during the US Special Forces operation that resulted in the death of Osama bin Laden on 1 May 2011. One such helicopter experienced mechanical trouble during the operation and the team was forced to destroy it before departing in two MH-47 Chinooks with bin Laden's remains. Two MH-47s were used for the mission to refuel the two MH-60s and as backups. Several media outlets have reported that Pakistani government has granted the Chinese military access to the remains of the crashed 'stealth' UH-60 variant in Abbotabad. Pakistan and China deny the reports, and the U.S. Government has not confirmed the Chinese access.
 

Colombia

Colombia first received UH-60s from the United States in 1987. The Colombian National Police, Colombian Air Force, and Colombian Army use UH-60s to mobilize troops and supplies to places which are difficult to access by ground for counter-insurgency (COIN) operations against drug and guerrilla organizations, as well as for search & rescue and medical evacuation.

Colombia also operates a militarized gunship version of the UH-60, with stub wings, locally known as Arpía (English: Harpy).
 

Israel

The Israeli Air Force (IAF) received 10 surplus UH-60A Black Hawks from the United States in August 1994. Named Yanshuf (English: Owl) by the IAF, the UH-60A began replacing Bell 212 utility helicopters of the Israeli Defense Forces.
 

The IAF first used the UH-60s in combat in April 1996, during operation "Grapes of Wrath" against the Hezbollah in southern Lebanon. In March 2000, three IAF UH-60s were used to ferry Pope John Paul II during his visit to Israel, with one helicopter carrying the Pope, another his medical team and a third available on constant standby.
 

Mexico

The Mexican Air Force ordered its first two UH-60Ls in 1991, to transport special forces units, and since then purchased another 4 in 1994. In July and August 2009, the Federal Police used UH-60s in attacks on drug traffickers. In 25 August 2011, the Mexican Navy received three UH-60M under the Merida Initiative aide package.
 

Republic of China (Taiwan)

Taiwan has operated S-70C-1/1A since the ROC Air Force received ten S-70C-1A and four S-70C-1 Bluehawk helicopters in June 1986 for Search And Rescue.[47] Four further S-70C-6s were received in April 1998. The ROC Navy received the first of ten S-70C(M)-1s in July 1990. 11 S-70C(M)-2s were received beginning April 2000. In January 2010, the US announced a Foreign Military Sale of 60 UH-60Ms to Taiwan for the ROC Army.
 

Turkey

Turkey has operated the UH-60 during NATO deployments to Afghanistan and the Balkans. The UH-60 has also been used in counter-terror/internal security operations.
 

The Black Hawk competed in the Turkish General Use Helicopter Tender against the AgustaWestland AW149. Under this project Turkey intends to order up to 115 helicopters and produce many of them indigenously. Turkish Aerospace Industries will be responsible for the final integration and assembly. On 21 April 2011, Turkey announced the selection of Sikorsky's T-70 for the tender.

Other and potential users

The United Arab Emirates has received 20 UH-60Ls by November 2010. The nation requested 14 UH-60M helicopters in September 2008 through a Foreign Military Sale. The package includes laser and radar warning sensors as well as weapons systems. Bahrain ordered 9 UH-60Ms in 2007.
 

Four UH-60L bought in 1997 for the peacekeeping forces of Brazilian Army in Peru-Ecuador border (MOMEP, Missão de Observação Militar Equador-Peru). Afterward they were assigned to 4th Aviation Army Battalion at Manaus. Brazil has requested 15 additional UH-60Ls through a Foreign Military Sale in 2008. Brazil's first two UH-60Ls were delivered in March 2011. They are operated by the Panther Squadron (5/8 GAv – Aviation Group), based at Santa Maria Air Force Base.
 

Sweden requested 15 UH-60M helicopters by a Foreign Military Sale in September 2010. On 9 April 2011, Swedish Minister for Defence Sten Tolgfors announced that the negotiations are almost finalized. Helicopter deliveries are to start in 2012. Swedish pilots will begin training on the helicopter this summer. The UH-60Ms are to be fully operational by 2017. On 18 May 2011, Sikorsky announced the sale of 15 UH-60Ms to Sweden with accelerated deliveries in 2011 and 2012.
 

In November 2011, it was reported that Sikorsky would sell 12 UH-60Ms to the Royal Brunei Air Force. On 12 June 2012, the US Defense Security Cooperation Agency notified Congress that Qatar requested the purchase 12 UH-60Ms, engines, and associated equipment.
 

Variants

The 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

• YUH-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.[68] 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. Produced 1989–2007.[70] UH-60Ls are also being equipped with the GE T700-GE-701D engine.

• 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 new glass cockpit. 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) cockpit suite. Flight testing began in August 2008