The UH-60 Black Hawk is a multipurpose helicopter created by the American company Sikorsky. The helicopter is in service with the American army, where it replaced the famous Bell UH-1, which is one of the symbols of the Vietnam War. The new rotorcraft was designed to transport 11 soldiers in full gear. A prototype of the helicopter took to the skies on October 17, 1974, and on December 23, 1976, the helicopter won a competition announced by the military and was put into mass production. The helicopter is still being produced. Since 1977, more than 4 thousand UH-60 Black Hawk helicopters of various modifications have been produced. The helicopter is familiar to the general public from the feature film "The Fall of the Black Hawk Down", which tells about the events in the capital of Somalia in 1993.
Development history
The creation of the UH-60 helicopter began after the US military issued Boeing-Vertol, Bell, Lockheed and Sikorsky with a task to design a multipurpose tactical helicopter designed to supply troops on the battlefield and conduct amphibious operations. The helicopter was created under the UTTAS program - Utility Tactical Transport Air System (multipurpose tactical transport helicopter). The new multipurpose helicopter was to replace the Boeing-Vertol CH-46 "Sea Knight" transport helicopter in service with the ILC, as well as the Bell UH-1 multipurpose army helicopter in service with the army. In 1971, the military decided on the requirements for the future vehicle: it was necessary to transport a rifle squad of 11-15 people in the helicopter cockpit; crew up to 3 people; ensuring the possibility of transporting the helicopter without disassembly on Lockheed C-130 and C-141 aircraft; equipping the machine with two motors.
The initial production program included the production of 1,100 helicopters, it was planned to be completed by 1985, at that time this program was the largest helicopter program in the American army. The cost of the entire program for the creation of the UTTAS helicopter, including the stage of development, acquisition and operation of machines for 10 years, was initially estimated by the US military at $ 2.4 billion, but then increased to $ 6.5 billion, and the price for one machine increased accordingly from 2 to 5.8 million dollars. In 1972, the military issued requirements for the flight characteristics of UTTAS helicopters and technical specifications to 9 manufacturing companies.
Of the 9 helicopter companies that presented their projects for the UTTAS helicopter, the Pentagon selected the developments of Sikorsky and Boeing-Vertol, which were to provide prototypes. According to the contract, it was provided for the construction of batches of 4 experimental helicopters from each of the firms. One helicopter was intended for static tests, 3 more machines for flight tests. After the military decided on the manufacturer, it was planned to build 5 more experimental helicopters so that all 8 machines could take part in operational tests.
In 1973, the UTTAS helicopter, developed for the military by the Sikorsky company, received the designation S-70 (in-house) and the military one - UH-60A. Experienced helicopter - YUH-60 first took to the skies on October 17, 1974. After the evaluation tests of prototypes were completed in 1976, the US military conducted a comparative analysis of the Sikorsky and Boeing-Vertol helicopters and opted for the Sikorsky helicopter. The main reasons for choosing the Sikorsky UH-60A multipurpose helicopter were lower operating costs over a 20-year design period and lower technical risks.
Description of construction
The fuselage of a semi-monocoque type helicopter, all-metal, is made of light alloys. Composite materials based on Kevlar and fiberglass are used in the construction of the cockpit, doors, fairings, lights and engine hoods. The fuselage has a shockproof design that can withstand an overload of 10g for vertical and 20g for a frontal impact. The rear of the fuselage of the vehicle smoothly passes into the tail boom with an asymmetrical profile and end boom bent upward, to which the tail rotor and stabilizer are attached. The stabilizer is straight, controlled, its span is 4, 37 m. The installation angle is changed using a control system that receives signals about the pitch angle, airspeed, lateral acceleration and angular speed. For ease of transportation and during parking, the tail boom is folded.
The entrance to the two-seater cockpit is made through 2 side doors, which are resettable. The pilots' seats are armored. The cargo compartment of the helicopter has dimensions of 4, 95x2, 21x1, 87 m, its volume is 11, 6 cubic meters. On both sides of the cargo compartment there are sliding doors measuring 1, 5x1, 75 m. The helicopter's cargo compartment can easily accommodate 11 soldiers with their weapons or 6 wounded soldiers on a stretcher.
The helicopter chassis is tricycle, non-retractable, has one wheel on each support. The main legs of the chassis are lever-type, they are equipped with two-chamber shock absorbers. The pneumohydraulic damping system installed on the helicopter allows the absorption of the energy of impact on the ground with an arising overload of 40g without touching the helicopter fuselage to the ground. The base of the helicopter chassis is 8, 83 m, the track of the chassis is 2, 7 m.
The main rotor of the helicopter is four-bladed, the blades are hinged. The bushing is monolithic, made of titanium alloy and has dampers and elastomer bearings that do not require lubrication. This, in turn, allows for a 60% reduction in maintenance work. The helicopter blades are rectangular in plan, have oval-section spars made of titanium alloy and a tail section, which uses a nomex honeycomb filler. The trailing edge as well as the butt of the blades are made of composite materials based on graphite. The blades are lined with fiberglass, and counterweights installed along the tip of the blade are made of this material. The blades of the helicopter are designed according to the principle of a harmlessly damaged structure, thanks to which they are able to withstand the impact of 23-mm artillery shells. The blades are equipped with an electrical anti-icing system.
The tail rotor of the helicopter is also four-bladed, its diameter is 3.35 m, the blades are not hinged. Together with the end beam, the tail rotor is inclined laterally at an angle of 20 degrees, which allows to increase the centering range and create a vertical thrust component. The bushing consists of 2 cross-shaped beams. In plan, the blades have a rectangular shape, made using a composite graphite-epoxy material, as well as the rotor blades have an electrical anti-icing system.
The power plant of the helicopter includes 2 General Electric T700-GE-700 turboshaft gas turbine engines, which are located in nacelles on both sides of the main rotor pylon. The maximum power of the T700-GE-700 engine was 1285 kW. This engine was developed taking into account the requirements that were obtained during the experience of operating helicopters in Vietnam. The fuel system of the car consisted of standard internal fuel tanks with a capacity of 150 liters, in addition to this, it was additionally possible to install another internal tank with a capacity of 440 liters. In versions of the NN-60 and MN-60 helicopter, drop tanks with a capacity of 870 liters could be mounted on high wing-shaped pylons. The maximum possible fuel supply of the helicopter is 3545 liters.
The helicopter control system is hydraulic, booster, redundant. The helicopter has an auxiliary power unit "Solar" with a capacity of 67 kW. It provides starting of the main engines, as well as the drive of the hydraulic system.
The main elements of the vehicle's navigation system were inertial navigation system and Doppler radar. Initially, it was possible to install a helicopter positioning system using satellites. The equipment provided for the defense of the helicopter includes an automatic dispersion machine for IR reflectors and tracers, as well as an ARP-39 radar radiation receiver.
Today, without any exaggeration, we can say that the Black Hawk Down is a combat vehicle of the 21st century, despite the fact that it is already over 40 years old. As a result of the development of this helicopter, a universal platform for all branches of the armed forces was born, which, in terms of the totality of its characteristics, occupies a leading position in the world. In addition to the basic ground weight UH-60, 2 anti-submarine helicopters SH-60F "Ocean Hawk" and SH-60B "Sea Hawk" were developed (these helicopters are equipped with a descending hydroacoustic station and magnetometers). The HH-60 "Rescue Hawk" helicopter was also designed for military search and rescue, as well as special operations, and the MH-60 "Knighthawk" line of helicopters, which includes fire support helicopters, deck helicopters, ambulance helicopters, helicopters for special operations and jammers.
Currently, the helicopter is still actively exported. Modern helicopter models are saturated to the limit with various high-tech equipment, which, in turn, does not allow storing the machine for a long time outside the hangar and makes high demands on the service personnel. The adoption of the UH-60 multipurpose helicopter, which is actively used by all branches of the armed forces, as well as in the navy, has significantly reduced operating costs and simplified maintenance. In the army, he replaced the famous UH-1 "Iroquois", and in the fleet "SeaSprite". At present, the helicopter successfully duplicates the tasks of fire support helicopters and transport vehicles, and also replaces the heavy SH-3 "Sea King" helicopters and the MH-53 sea minesweepers.
Flight technical characteristics of the UH-60L:
Dimensions: main rotor diameter - 16, 36 m, tail rotor diameter - 3, 35 m, length with blades - 19, 26 m, fuselage width - 2, 36 m, height - 5, 13 m.
The empty weight of the helicopter is 4819 kg, the maximum take-off weight is 10660 kg.
Engine type - 2 turboshaft General Electric T700-GE-701C, 2x1890 hp.
Maximum speed - 295 km / h, cruising speed - 278 km / h.
Combat radius of action - 592 km.
Ferry range - 2220 km.
Service ceiling - 5790 m.
Crew - 2 people. plus up to 2 machine gun operators.
Payload - 1200 kg. inside the fuselage, on the suspension - 4100 kg, including 11 soldiers or 6 stretchers for the wounded.
Armament (optional): 2x7, 62 mm M240H machine gun or 2x12, 7 mm GAU-19 machine gun inside the cockpit. Combat load - up to 4536 kg on 4 hardpoints: guided and unguided air-to-surface and air-to-air missiles, artillery mounts of 20 and 30-mm caliber.
