AH-64 Apache Attack Helicopter
The AH-64 Apache is the first military helicopter developed to interact with ground forces at the forefront, as well as for anti-tank operations at any time of the day, in poor visibility conditions and in difficult meteorological conditions with a high degree of survival, survivability and return to build The Apache helicopter was designed exclusively for offensive operations with maximum surprise actions (based on the principle of "fight and survive"). The tactical and technical requirements of the army for the AH-64A Apache helicopter with 8 armament, Nelfire ATGM and 320 30-mm shells included the vertical rate of 2,3 m / s at the height of 1220 m at 35 ° C, cruiser speed XNXX / s, and the cruiser speed XNXX / s at a height of 269 m at 1220 ° C, cruiser speed XNXX / s, and the cruiser speed XNXX / s at a height of 1 m at 50 ° C, cruiser speed XNXX / s, and the cruiser speed XNXX / s at a height of XNUMX m at the temperature XNUMX ° C, cruiser speed XNXX / s at altitude XNUMX m and flight duration when performing a standard task XNUMX h XNUMX min.
The requirements provided for the estimated service life of the 4500 helicopter for hours, the ability to operate in sandy conditions for 450 hours, flight safety in rain and moderate icing conditions, crew survival during vertical landing at 12,8 speed m / s. The requirements provided for the ability to perform the task when hit by a single bullet caliber 12,7 mm and ensure maximum survivability when hit a single projectile caliber 23 mm. In accordance with the standard assignment, it was possible to fly to the combat zone using instruments and conduct an attack with visibility 800 m and cloud height around 60 m. The prototype of the helicopter made the first flight 30 September 1975 of the year; The first three pre-production samples were handed over to the US Army for testing in June of the 1979 of the year; in December of the 1994 of the year, the last of the 811 ordered helicopters of this type was manufactured.Design.
Structurally, the AN-64A helicopter is designed according to a single-rotor scheme with four-bladed main and tail rotors, a mid wing with a small span and a three-post non-retractable wheeled chassis with a tail wheel. The helicopter has a fuselage made of aluminum alloys; aircraft type with a relatively small cross section that reduces the effective area of dispersion. Double crew cabin is in front. Chairs in it are installed according to the "tandem" scheme, on the front there is an arrow-operator, and in the rear, raised by 0,48 m for improved visibility, is a pilot. The armor, protecting the cabin from the bottom and from the sides, as well as the armored partition between the seats are made of Kevlar composite material. In the operator's cab, except for the selection panel weapons and control it, has all the necessary instruments and controls for independent flight and landing. Along with the twin-engine power plant and duplicated helicopter control system, this significantly increases the helicopter's survivability in combat. The helicopter has a mid-wing with automatic flaps and a span of 5,23 m. There are four weapon suspension units under the wing, while the pylons with weapons suspended on them rockets can rotate at an angle of 5° upwards and up to 28° downwards.
Equipment.
The helicopter is equipped with powerful electronic equipment - a total of about 220 units. The sighting and navigation equipment includes the TADS / PNVS electron-optical system, the IHADSS integrated helmets system, the Doppler radar, the AN / ASN-143 inertial navigation system and the radio altimeter. Communications equipment includes four radio stations and security equipment. To ensure accuracy of hitting a target from an Apache AH-64A helicopter with various types of weapons, primarily ATF Helfire, the helicopter uses the integrated aim-navigation system TADS / PNVS from Martin-Marietta to identify the target and night vision. The TADS system combines five subsystems that allow you to detect and identify targets in a matter of seconds at any time of the day and in difficult weather conditions in a matter of seconds, and determine their range and coordinates with high accuracy. The TADS system includes the following subsystems: laser rangefinder, target designator (LRF / D); Front hemisphere infrared night vision system (FLIR); optical system of direct vision (DVO); daytime television display (DT); laser tracking unit. All this equipment is located in a barrel-shaped fairing in the bow of the helicopter. Subsystems transmit signals for display on the windshield of the pilot and operator.
The PNVS night vision system includes infrared night vision systems in the front hemisphere, the sensor of which, brought out into the nose of the fuselage above the TADS system, is connected via an optoelectronic tracking system with movements of the head of the pilot or operator. Thus, the helmet-mounted tracking system is oriented in accordance with the direction of the head of the pilot or operator. Data from the PNVS system (used primarily for piloting and target detection) and from the TADS system are displayed on the monocular of the integrated display and aiming system IHADSS. The IHADSS system allows the crew to analyze information in the process of observing the target, aiming the weapon systems, seeing the target, agreeing on the data of the sight lines between the pilot and the operator, directing the TADS / PNVS systems to target designation. The FLIR subsystem included in TADS, if necessary, can be used in the PNVS system as a backup. The pilot or operator using the handle on the control stick (to the left of the seat) has the ability to orient the TADS FLIR subsystem in the + 120 ° range in azimuth and from + 30 ° to -60 ° in elevation. PNVS system deviation angles: + 90 ° in azimuth and from + 20 ° to -45 ° in elevation.
Power point.
In the design of the four-bladed main rotor and the four-bladed tail rotor, Toul Research and Engineering blades are used. The blade of the main rotor of the five-spar design, has a rectangular shape in plan with an arrow-shaped tip. The spars are made of stainless steel and reinforced with tubular power gaskets made of fiberglass. The sheathing of the blade is made of stainless steel; the tail section is made of composite materials. The design of the blade has a high durability: the service life of more than 4500 hours. The blades can be folded or dismantled when the Apache helicopters are transported by Lockheed C-141 aircraft (holds 2 helicopters) and C-5A (holds 6 helicopters). The blade attachment system reflects the experience of Hughes, accumulated during the development of the OH-6A light helicopter, which used a system of elastic torsion plates with elastomeric dampers in the plane of rotation and spaced horizontal joints. Main rotor blades have a HH-02 profile. The steering screw is mounted on the left side of the arrowed keel. It consists of two two-bladed screws mounted in an X-shaped pattern, in which the blades are located at angles 55 and 125 ° to each other, which ensures optimal noise reduction. In the tail rotor blades, the NACA 64A006 profile is used. The helicopter engines are located in gondolas on the sides of the fuselage. Such a significant separation of engines is a measure to prevent the failure of both engines with a single shot at a helicopter.
Experienced helicopters were equipped with a General Electric YT700 or T700-GE-700 TVD (rated engine power 1560 hp). General Electric has prepared a more powerful version under the designation T700-GE-401 (designation for the army T700-GE-701) in accordance with the requirements fleet USA to anti-submarine helicopter Sikorsky SH-60B Sea Hawk. In 1983, General Electric supplied the army with the first production T700-GE-701 TVDs for installation on Apache helicopters. The new AH-64D helicopters are equipped with modified T700-GE-701C engines with increased power. The engines have a modular design and are equipped with built-in centrifugal air purifiers (dust protection devices), which ensure the removal of up to 95% of dust and sand sucked into the air intake.
The exhaust devices of the engines are equipped with the "Black Hole" system, which reduces thermal radiation. The total capacity of the two protected fuel tanks is about 1 420 liters. The transmission includes main and intermediate gearboxes, tail rotor and engine gearboxes, connecting shafts. The power of the engines with integrated gearboxes is transmitted to the main gearbox and through the shaft of the drive of the steering screw to the steering screw. The intermediate gearbox and the steering screw drive gearbox operate on grease lubrication to reduce the risk of failure from the action of bullets and shrapnel. If the lubricating oil is consumed or leaked, the main gearbox can operate without lubrication for 1 hours. The transmission elements are supplied by Lytton and Ercraft Gear.
Armament.
For the helicopter AN-64A, the American firms "Martin Marietta" and "Wesminghouse" have developed aviation AAWWS Longbow all-weather weapon system, which should be included as one of the main elements in the program for the phased improvement of this helicopter. The main components of this system are a millimeter-wave rotating antenna located above the rotor hub of the helicopter, the Hellfire ATGM with a new homing radar (instead of laser) and the corresponding electronic equipment installed in the fuselage and the helicopter cockpit. The Hellfire missile has a length of 1,76 m, a diameter of 0,18 m, a wingspan of 0,33 m, and a launch weight of 43 kg. It is equipped with a cumulative warhead (9 kg), which is able to penetrate the frontal armor of modern tanks. The AAWWS system provides the ability to combat tanks in difficult weather conditions, since millimeter-wave radars, unlike optical weapons, including laser, can successfully operate in fog and rain. The built-in armament of AN-64A Apache helicopters consists of a single-barrel 30-mm M230 gun mounted in a turret in the lower part of the fuselage under the operator-gunner’s seat.
The rate of fire of this gun 625 shots per minute, the effective range of ground targets 3 000 m. To fight the tanks, the helicopter is armed with Hellfire ATGM with a semi-active laser homing head. Up to four XS of such missiles can be placed on the four sub-winged sub-assemblies. If necessary, instead of the ATGM, each launcher can also house one launcher, each of which contains 16 unguided aircraft with 19 mm caliber.
The following modifications of the helicopter were developed:
YAH-64A - prototype helicopter just-over-year by Hughes. Along with Bell's YAH-63, he participated in the US Army Advanced Attack Helicopter competition. Were built (1975 year): YAH-64A GTV (designation AV-01) - machine for ground tests, and two helicopters (AV-02 and AV-03) to participate in competitive flights. After the conclusion of the contract, they were modified several times. In the 1979 year, two more AV-04 flight models (subsequently crashed) and AV-05 for army tests were built.
AH-64A - a serial helicopter created on the "standard" YAH-64A AV-05. Produced from 1983 to 1994 year. The very first serial AH-64A had the designation PV-01. In addition to the US Army, helicopters of this modification were supplied to the armed forces of Israel, the Netherlands, Saudi Arabia, Egypt, Greece and the United Arab Emirates. By the 2010, it is planned to replace all helicopters of this type, which are in service with the US Army, with AH-64D (without Longbow radar).
GAH-64A - AH-64A version adapted for training and training flights. Built 17 helicopters.
JAH-64A - AH-64A version for special flight studies. The helicopter is additionally equipped with systems for recording flight parameters and system operation, as well as a system for transmitting this data to ground personnel. Built 7 helicopters.
AH-64B (Apache Bravo) is a modification featuring an increased wing, new communication and navigation tools (including GPS), and increased protection against weapons of mass destruction. Take-off weight increased by 122 kg, compared with AH-64A. According to the program, it was planned to modify the 254 helicopter AH-64A. The program was never implemented (discontinued in 1990 year).
AH-64G (Advanced Apache) - AH-64B modification for NATO countries (another possible designation is AH-64B / G). It was planned to equip with new engines and EDS, installation of avionics at the request of the customer. There was the possible use of AAWWS Longbow. The program was abandoned in 1990 due to the lack of orders.
AH-64 Sea Going Apache - sea modification of a helicopter with armament of anti-ship harpoon (Harpoon) and Penguin (Penquin). The program is closed at the development stage.
AN-64С - modification AH-64A taking into account the accumulated operating experience. Had a new improved avionics. Very close to the AH-64D (excluding the installation of new engines and Longbow radar). In 1993, the program was transformed into a modification of helicopters up to AH-64D and the designation AH-64C was no longer used.
AH-64D Longbow - a new modification of the helicopter based on the AH-64C with Longbow super-articulated radar and more powerful engines (-701C). All AH-64A US Army plans to finalize up to AH-64D (without Longbow radar).
WAH-64D is an AH-64D variant for the British Army (licensed production by Westland). It differs from AH-64D engines of "Rolls Royce". Built 67 helicopters.
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