Eko Triyanggono: Helicopter

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Northrop Grumman MQ-8 Fire Scout

The Northrop Grumman MQ-8 Fire Scout is an unmanned autonomous helicopter developed by Northrop Grumman for use by the United States Armed Forces. The Fire Scout is designed to provide reconnaissance, situational awareness, and precision targeting support for ground, air and sea forces. The initial RQ-8A version was based on the Schweizer 330, while the enhanced MQ-8B was derived from the Schweizer 333.

Design and Development

RQ-8A

As the US Navy was withdrawing its RQ-2 Pioneers from service, it began to seek a second generation UAV. The Navy requirement specified a vertical takeoff & landing (VTOL) aircraft, with a payload capacity of 90 kilograms (200 pounds), a range of 125 miles (200 km), an endurance on station of three hours at an altitude of 20,000 ft (6 km), and the ability to land on a ship in a 46 km/h (29 mph) wind. The UAV was to fly 190 hours before planned maintenance.

There were three finalists in the competition, which was designated "VTOL-UAV" or "VTUAV". Bell, Sikorsky, and a collaboration of Teledyne Ryan and Schweizer Aircraft submitted designs. The Ryan-Schweizer UAV was selected as the winner in the spring of 2000. The RQ-8A Fire Scout, as it was named, was a derivative of the Schweizer three-passenger, turbine powered 330SP helicopter, with a new fuselage, new fuel system, and UAV electronics and sensors. The initial prototype of the Fire Scout was piloted in initial tests, flying autonomously for the first time in January 2000. The Rolls-Royce 250-C20 turbine engine ran on JP-8 and JP-5 jet fuel (the latter of which has a lower flashpoint and is considered safe for shipboard storage and use).

The Fire Scout was to be fitted with a sensor ball turret that carries electro-optic and infrared cameras, and a laser range finder. It was to be controlled over a data link derived from the Northrop Grumman RQ-4 Global Hawk UAV, operating over a line of sight to a distance of 172 miles (280 km). The control system was to be fitted onto a ship, or could be carried on a Humvee light vehicle for US Marine service.

MQ-8B

Although progress on the project had been regarded as satisfactory, the Navy decided the Fire Scout didn't meet their needs after all, and cut funding for production in December 2001. However, the development program continued, and Northrop Grumman pitched a range of improved configurations to anyone who was interested. As it turned out, the U.S. Army was very interested, awarding a contract for seven improved RQ-8B evaluation machines in late 2003. In 2006, it was redesignated MQ-8B.

The MQ-8B features a four-blade main rotor, in contrast to the larger-diameter three-blade rotor of the RQ-8A, to reduce noise and improve lift capacity and performance. The four-blade rotor had already been evaluated on Fire Scout prototypes. They boost gross takeoff weight by 500 pounds to 3,150 pounds (by 225 kg to 1,430 kg), with payloads of up to 700 pounds (320 kg) for short-range missions.

The MQ-8B is fitted with stub wings which serve both an aerodynamic purpose as well as an armament carriage location. Weapons to be carried include Hellfire missiles, Viper Strike laser-guided glide weapons, and, in particular, pods carrying the "Advanced Precision Kill Weapon System (APKWS)", a laser-guided 70 millimeter (2.75 inch) folding-fin rocket, which the Army saw as ideal for the modern battlefield. The Army was also interested in using the Fire Scout to carry up to 200 pounds (90 kg) of emergency supplies to troops in the field.

The MQ-8B is being modified to permit rapid swap out of payload configurations. The current sensor configuration of a day/night turret with a laser target designator will remain an option. Alternate sensor payloads in consideration include a TSAR with Moving Target Indicator (MTI) capability, a multispectral sensor, a SIGINT module, the Target Acquisition Minefield Detection System (ASTAMIDS), and the Tactical Common Data Link (TCDL). The Army wanted the Fire Scout to operate as an element of an integrated ground sensor network as well.

Production of the flight test airframes was initiated in April 2006 at the Northrop Grumman Unmanned Systems production plant in Moss Point, Mississippi. The Navy approved low-rate initial production. The first flight of the MQ-8B took place on 18 December 2006 at Naval Air Station Patuxent River. The Army interest revived Navy interest in the program, with the Navy ordering eight Sea Scout MQ-8B derivatives for evaluation. In January 2010, the Army terminated its involvement with the Fire Scout, contending that the RQ-7 Shadow UAV could meet the Army's needs.

The MQ-8B complements the manned aviation detachments onboard Air Capable ships and is deployed along with either an SH-60B HSL/HSM detachment or a MH-60S HSC detachment. With the planned addition of RADAR, AIS, and weapons, the MQ-8B will provide many of the capabilities currently provided by the SH-60B. It will give the ship and embarked air detachment greater flexibility in meeting mission demands, and will free manned aircraft for those missions.

Northrop Grumman has started work outfitting the MQ-8B with a weapons system. The Advanced Precision Kill Weapon System laser-guided 70 mm rocket. The corporation will develop and deliver the equipment needed to control the weapons system under a $17 million contract awarded to the company 23 September 2011 by Naval Air Systems Command. Final delivery of an operational system is expected by March 2013.

On 30 December 2012, the Navy issued an urgent order to install RDR-1700 maritime-surveillance radars on nine MQ-8B Fire Scouts. Installation should be completed by the end of 2013. The system consists of the radar, modified MQ-8B radome, and interfaces into the helicopter UAV and its control station. The radar weighs 71 lb and will be mounted underneath the helicopter to give 360-degree coverage. It is an X-band synthetic aperture radar that can show objects in a detailed way. Detailed range is out to 25 km (16 mi), with a max range of 80 km (50 mi). The RDR-1700 can see through clouds and sandstorms and can be used for terrain mapping or for weather detection. It can track 20 air or surface targets and can use a target-marker to determine the range, bearing, and velocity of a target. MQ-8B UAVs with the radar could be useful in the Persian Gulf to track small Iranian speed boats, or the Gulf of Aden to locate Somali pirates.

MQ-8C Fire-X

On 3 May 2010, Northrop announced plans to fly a Bell 407 helicopter modified with autonomous controls from the MQ-8B. Named Fire-X, it was designed to demonstrate an unmanned cargo resupply capability to the US Navy. The unmanned Fire-X completed its first flight at Yuma Proving Ground in Arizona on 20 December 2010. On 23 April 2012, Northrop received a $262.3 million contract from the Navy to develop and build the newly designated MQ-8C version of the Fire Scout. The contract calls for Northrop to build and test two developmental aircraft over the next 26 months. The company is also contracted to build six low-rate production aircraft at the same time. The Navy wants 28 MQ-8Cs for naval special operations forces. The MQ-8C weighs 2.7 tons, has a 1,000 lb payload, and has an endurance of up to 24 hours. It can be armed with AGM-175 Griffin missiles and APKWS II guided 70 mm rockets that the MQ-8B can carry, as well as heavier AGM-114 Hellfire missiles. The MQ-8C is expected to enter service in 2014. In March 2013, the Navy incorporated the Rolls-Royce 250-C47E into the MQ-8C. The new engine has a 5% increase in "hot and high" power, 2% reduced fuel consumption, 8% increase in rated takeoff power to 700 shaft horsepower, and better reliability.

Operational History

In January 2006, an RQ-8A Fire Scout landed aboard the U.S. Navy warship USS Nashville while it was steaming off the coast of Maryland near the Patuxent River. This marked the first time an unmanned helicopter has landed autonomously aboard a moving U.S. Navy ship without a pilot controlling the aircraft. The USS Nashville, which is an amphibious transport ship, was maneuvering as fast as 17 mph (27 km/h) in the tests.

The flight test program is underway. Production aircraft will eventually be deployed on the Navy's Littoral Combat Ships. In February 2008, the U.S. Navy announced that they would integrate the MQ-8B Fire Scout VTUAV onto another air-capable ship before it reaches the Littoral Combat Ship (LCS)

The Fire Scout is a key enabler for LCS and significantly contributes to its designated warfare mission areas of anti-submarine warfare, surface warfare and mine warfare. The modular nature of the ship to accomplish the designated mission is complemented by the Fire Scout and its modular mission payload capability. However, due to changes in the LCS development schedule, the Navy conducted the Fire Scout Operational Evaluation (OpEval) aboard USS McInerney (FFG-8). This will provide the fleet with unmanned aerial system support as soon as possible. The Fire Scout first embarked aboard the guided-missile frigate USS McInerney, an Oliver Hazard Perry-class frigate, while in port for operational fit checks and ship integration testing on December 10, 2008. The Fire Scout was slated to deploy aboard USS McInerney during its next counter-narcotics trafficking deployment later in 2009.

According to the current schedule, the Navy conducted Technical Evaluation on the Fire Scout on the FFG-8 in the fall 2008 and Operational Evaluation in the summer 2009. The Fire Scout was to reach Initial Operating Capability soon after the evaluation. The Navy will continue to support LCS Initial Operational Test and Evaluation (IOT&E) efforts in fiscal year 2011.

Flight tests took place 4–8 May 2009 off the coast of Mayport, Fla. The U.S. Navy Fire Scout completed test flights in areas of shipboard deck motion and wind envelope expansion and landings including the use of the grid and harpoon system. During the five days of testing, the ship/aircraft team compiled 19 flight hours during 12 flights, which included 54 landings, 37 of which were into the NATO standard grid.

In September 2009, the Navy announced the first deployment of the MQ-8B aboard McInerney. On 3 April 2010, an MQ-8 from McInerney detected a "go-fast" open speedboat and a support vessel engaged in smuggling cocaine in the Eastern Pacific, allowing the ship to confiscate 60 kg of cocaine and detain a number of suspects. On 2 August 2010 an MQ-8 became unresponsive to commands during testing and entered restricted airspace around Washington, D.C. In May 2011, three MQ-8s were deployed to northern Afghanistan for intelligence, surveillance, and reconnaissance (ISR), a mission which has been extended another year. On 21 June 2011, a MQ-8 operating from USS Halyburton (FFG-40) as part of Operation Unified Protector was shot down over Libya during a surveillance and reconnaissance mission. Aboard the Halyburton, the Fire Scouts were flown and maintained by the ship's SH-60 detachment, HSL-42.

The U.S. Navy briefly grounded the MQ-8B Fire Scout after two of the aircraft crashed overseas within a week. In the first incident, the Navy said a Fire Scout crashed off the coast of Africa on 30 March after it was unable to land on the US Navy Oliver Hazard Perry-class frigate USS Simpson (FFG-56) at the end of a surveillance mission. On 6 April 2012, another Fire Scout crashed in Afghanistan. An investigation into the crash in Afghanistan determined the cause was a faulty navigation system. The cause of the crash near the USS Simpson (FFG-56) remains less clear, so the result was tougher maintenance procedures put in place to prevent a faulty copter from going on-mission. The Fire Scout was back flying over Afghanistan by May, and returned to sea-based ISR "anti-piracy" operations by August.

The U.S. Navy has continued to deploy the MQ-8B to the African AOR with deployments in USS Klakring (FFG 42) and USS Robert G. Bradley (FFG 49). In each of the deployments the UAV has exceeded 500 flight hours, while providing critical ISR coverage for AFRICOM and 6th Fleet.

General characteristics

Crew	0
Payload	600 lb (272 kg)
Length	23.95 ft (7.3 m)
Rotor diameter	27.5 ft (8.4 m)
Height	9.71 ft (2.9m)
Empty weight	2,073 lb (940.3 kg)
Max. Take off weight	3,150 lb (1,430 kg)
Powerplant	1 x Rolls-Royce 250, 313 kW (420 hp)

Performance

Maximum speed	115 knots (213 km/h)+
Cruise speed	110 knots (200 km/h)
Combat radius	110 nmi (203.7 km) with 5+ hours on station
Endurace	8 hours
Service ceiling	20,000 ft (6,100 m)

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Bell UH-1 Iroquois - Huey

The Bell UH-1 Iroquois (unofficially Huey) is a military helicopter powered by a single, turboshaft engine, with a two-bladed main rotor and tail rotor. The helicopter was developed by Bell Helicopter to meet the United States Army's requirement for a medical evacuation and utility helicopter in 1952, and first flew on 20 October 1956. Ordered into production in March 1960, the UH-1 was the first turbine-powered helicopter to enter production for the United States military, and more than 16,000 have been produced worldwide.

The first combat operation of the UH-1 was in the service of the U.S. Army during the Vietnam War. The original designation of HU-1 led to the helicopter's nickname of Huey. In September 1962, the designation was changed to UH-1, but "Huey" remained in common use. Approximately 7,000 UH-1 aircraft saw service in Vietnam.

Design

The UH-1 has a metal fuselage of semi-monocoque construction with tubular landing skids and two rotor blades on the main rotor. Early UH-1 models featured a single Lycoming T53 turboshaft engine in versions with power ratings from 700 shp (522 kW) to 1,400 shp (1,040 kW). Later UH-1 and related models would feature twin engines and four-blade rotors. The width was decided by the length of a standard Army medical litter.

All aircraft in the UH-1 family have similar construction. The UH-1H is the most-produced version, and is representative of all types. The main structure consists of two longitudinal main beams that run under the passenger cabin to the nose and back to the tail boom attachment point. The main beams are separated by transverse bulkheads and provide the supporting structure for the cabin, landing gear, under-floor fuel tanks, transmission, engine and tail boom. The main beams are joined at the lift beam, a short aluminum girder structure that is attached to the transmission via a lift link on the top and the cargo hook on the bottom and is located at the aircraft's centre of gravity. The lift beams were changed to steel later in the UH-1H's life, due to cracking on high-time airframes. The semi-monocoque tail boom attaches to the fuselage with four bolts.

The UH-1H's dynamic components include the engine, transmission, rotor mast, main rotor blades, tail rotor driveshaft, and the 42-degree and 90-degree gearboxes. The transmission is of a planetary type and reduces the engine's output to 324 rpm at the main rotor. The two-bladed, semi-rigid rotor design, with pre-coned and under-slung blades, is a development of early Bell model designs, such as the Bell 47 with which it shares common design features, including a dampened stabilizer bar. The two-bladed system reduces storage space required for the aircraft, but at a cost of higher vibration levels. The two-bladed design is also responsible for the characteristic 'Huey thump' when the aircraft is in flight, which is particularly evident during descent and in turning flight. The tail rotor is driven from the main transmission, via the two directional gearboxes which provide a tail rotor speed approximately six times that of the main rotor to increase tail rotor effectiveness.

The UH-1H also features a synchronized elevator on the tail boom, which is linked to the cyclic control and allows a wider center of gravity range. The standard fuel system consists of five interconnected fuel tanks, three of which are mounted behind the transmission and two of which are under the cabin floor. The landing gear consists of two arched cross tubes joining the skid tubes. The skids have replaceable sacrificial skid shoes to prevent wear of the skid tubes themselves. Skis and inflatable floats may be fitted.

Internal seating is made up of two pilot seats and additional seating for up to 13 passengers or crew in the cabin. The maximum seating arrangement consists of a four-man bench seat facing rearwards behind the pilot seats, facing a five-man bench seat in front of the transmission structure, with two, two-man bench seats facing outwards from the transmission structure on either side of the aircraft. All passenger seats are constructed of aluminium tube frames with canvas material seats, and are quickly removable and reconfigurable. The cabin may also be configured with up to six stretchers, an internal rescue hoist, auxiliary fuel tanks, spotlights, or many other mission kits. Access to the cabin is via two aft-sliding doors and two small, forward-hinged panels. The doors and hinged panels may be removed for flight or the doors may be pinned open. Pilot access is via individual hinged doors. While the five main fuel tanks are self-sealing, the UH-1H was not equipped with factory armour, although armoured pilot seats were available.

The UH-1H's dual controls are conventional for a helicopter and consist of a single hydraulic system boosting the cyclic stick, collective lever and anti-torque pedals. The collective levers have integral throttles, although these are not used to control rotor rpm, which is automatically governed, but are used for starting and shutting down the engine. The cyclic and collective control the main rotor pitch through torque tube linkages to the swash plate, while the anti-torque pedals change the pitch of the tail rotor via a tensioned cable arrangement. Some UH-1Hs have been modified to replace the tail rotor control cables with torque tubes similar to the UH-1N Twin Huey.

Specifications

General characteristics

Crew	1-4
Capacity	3,880 lb including 14 troops, or 6 stretchers, or equivalent cargo
Length	57 ft 1 in (17.40 m) with rotors
Width	8 ft 7 in (2.62 m) (Fuselage)
Height	14 ft 5 in (4.39 m)
Empty weight	5,215 lb (2,365 kg)
Gross weight	9,040 lb (4,100 kg)
Max takeoff weight	9,500 lb (4,309 kg)
Powerplant	1 × Lycoming T53-L-11 turboshaft, 1,100 shp (820 kW)
Main rotor diameter	48 ft 0 in (14.63 m)

Performance

Maximum speed	135 mph (217 km/h; 117 kn)
Cruise speed	125 mph (109 kn; 201 km/h)
Range	315 mi (274 nmi; 507 km)
Service ceiling	19,390 ft (5,910 m)
Rate of climb	1,755 ft/min (8.92 m/s)
Power/mass	0.15 hp/lb (0.25 kW/kg)

Armament

Variable, but may include a combination of:

2 x 7.62 mm M60 machine gun, or 2 7.62 mm GAU-17/A machine gun

2 x 7-round or 19-round 2.75 in (70 mm) rocket pods

2 x 7.62 mm Rheinmetall MG3 (German Army and German Luftwaffe)

2 x .303 Browning Mk II (Rhodesian, twin machine guns mounted on port side)

AH-1Z Viper

The Bell AH-1Z Viper is a twin-engine attack helicopter based on the AH-1W SuperCobra, that was developed for the United States Marine Corps. The AH-1Z features a four-blade, bearingless, composite main rotor system, uprated transmission, and a new target sighting system. The AH-1Z is part of the H-1 upgrade program. It is also called "Zulu Cobra" in reference to its variant letter.

Development

Background

Aspects of the AH-1Z date back to the Bell 249 in 1979, which was basically an AH-1S equipped with the four-blade main rotor system from the Bell 412. This helicopter demonstrated Bell's Cobra II design at the Farnborough Airshow in 1980. The Cobra II was to be equipped with Hellfire missiles, a new targeting system and improved engines. Later came the Cobra 2000 proposal which included General Electric T700 engines and a four-blade rotor. This design drew interest from the US Marine Corps, but funding was not available. In 1993, Bell proposed an AH-1W-based version for the UK's new attack helicopter program. The derivative design, named CobraVenom, featured a modern digital cockpit and could carry TOWs, Hellfire or Brimstone missiles. The CobraVenom design was altered in 1995 by changing to a four-blade rotor system. The design lost to the AH-64D later that year however.

H-1 Upgrade Program

In 1996, the USMC launched the H-1 upgrade program by signing a contract with Bell Helicopter for upgrading 180 AH-1Ws into AH-1Zs and upgrading 100 UH-1Ns into UH-1Ys. The H-1 program created completely modernized attack and utility helicopters with considerable design commonality to reduce operating costs. The AH-1Z and UH-1Y share a common tail boom, engines, rotor system, drive train, avionics architecture, software, controls and displays for over 84% identical components.

Bell participated in a joint Bell-Government integrated test team during the engineering manufacturing development (EMD) phase of the H-1 program. The AH-1Z program progressed slowly from 1996 to 2003 largely as a research and development operation. The existing two-blade semi-rigid, teetering rotor system is being replaced with a four-blade, hingeless, bearingless rotor system. The four-blade configuration provides improvements in flight characteristics including increased flight envelope, maximum speed, vertical rate-of-climb, payload and reduced rotor vibration level.

The AH-1Z first flew on 8 December 2000. Bell delivered three prototype aircraft to Naval Air Systems Command (NAVAIR) at Naval Air Station Patuxent River in July 2002, for the flight test phase of the program. Low-rate initial production began in October 2003, with deliveries to run through 2018. In February 2008, the United States Navy adjusted the contract, with the last 40 AH-1Zs to be built as new airframes instead of the previously planned rebuild of AH-1Ws. In September 2008, the Navy requested an additional 46 airframes for the Marine Corps, bringing the total number ordered to 226. In 2010, the Marine Corps plans to order 189 AH-1Zs with 58 of them being new airframes, with deliveries to continue until 2019. On 10 December, the Department of the Navy approved full-rate production.

Design

The AH-1Z incorporates new rotor technology with upgraded military avionics, weapons systems, and electro-optical sensors in an integrated weapons platform. It has improved survivability and can find targets at longer ranges and attack them with precision weapons.

The AH-1Z's new bearingless, hingeless rotor system has 75% fewer parts than that of four-bladed articulated systems. The blades are made of composites, which have an increased ballistic survivability, and there is a semiautomatic folding system for storage aboard amphibious assault ships. Its two redesigned wing stubs are longer, with each adding a wing-tip station for a missile such as the AIM-9 Sidewinder. Each wing has two other stations for 2.75-inch (70 mm) Hydra 70 rocket pods, or AGM-114 Hellfire quad missile launchers. The Longbow radar can also be mounted on a wing tip station.

The Z-model's integrated avionics system (IAS) has been developed by Northrop Grumman. The system includes two mission computers and an automatic flight control system. Each crew station has two 8x6-inch multifunction liquid crystal displays (LCD) and one 4.2x4.2-inch dual function LCD display. The communications suite combines a US Navy RT-1824 integrated radio, UHF/VHF, COMSEC and modem in a single unit. The navigation suite includes an embedded GPS inertial navigation system (EGI), a digital map system and a low-airspeed air data subsystem, which allows weapons delivery when hovering.

The crew are equipped with the Thales "Top Owl" helmet-mounted sight and display system. The Top Owl has a 24-hour day/night capability and a binocular display with a 40° field of view. Its visor projection provides forward looking infrared (FLIR) or video imagery. The AH-1Z has survivability equipment including the Hover Infrared Suppression System (HIRSS) to cover engine exhausts, countermeasure dispensers, radar warning, incoming/on-way missile warning and on-fuselage laserspot warning systems.

The Lockheed Martin target sight system (TSS) incorporates a third-generation FLIR sensor. The TSS provides target sighting in day, night or adverse weather conditions. The system has various view modes and can track with FLIR or by TV. The same system is also used on the UH-1Y Venom and the KC-130J Harvest HAWK.

Bell UH-1Y Venom

The Bell UH-1Y Venom, also called Super Huey, is a twin-engine medium size utility helicopter, part of the United States Marine Corps' H-1 upgrade program. The helicopter is also called Yankee for its variant letter, Y.

The UH-1Y is currently in full-rate production to replace the USMC's aging fleet of UH-1N Twin Huey light utility helicopters first introduced in the early 1970s. The UH-1Y was to have been remanufactured from UH-1Ns, but in 2005 it was approved for the aircraft to be built as new.

Development of Bell UH-1Y Venom

In 1996, the United States Marine Corps launched the H-1 upgrade program by signing a contract with Bell Helicopter for upgrading 100 UH-1Ns into UH-1Ys and upgrading 180 AH-1Ws into AH-1Zs. The H-1 program created completely modernized attack and utility helicopters with considerable design commonality to reduce operating costs. The UH-1Y and AH-1Z share a common tail boom, engines, rotor system, drive train, avionics architecture, software, controls and displays for over 84% identical components.

The Y-model updates an airframe that has been central to the Marine Corps aviation in Iraq. The Huey has many mission requirements including command and control (C2), escort, reconnaissance, troop transport, medical evacuation and close air support. Typically detachments of 2-4 Hueys have been deployed with detachments of 4-8 Cobras. The forward mounted weaponry of the Cobra combined with the door guns of the Huey provides a 240° field of fire.

Over the years new avionics and radios, in addition to modern door guns and safety upgrades, have greatly increased the UH-1N's empty weight. With a maximum speed of approximately 100 knots (190 km/h) and an inability to lift much more than its own crew, fuel and ammunition, the UH-1N, while useful, is limited in its utility.

The Y-model upgrades pilot avionics to a glass cockpit, adds further safety modifications and provides the UH-1 with a modern FLIR system. However, the biggest improvement is an increase in engine power. By replacing the engines and the two bladed rotor system with four composite blades the Y-model will return the Huey to the utility role for which it was designed. Originally the UH-1Y was to have been remanufactured from UH-1N airframes, but in April 2005 approval was granted to build them as new helicopters.

Bell delivered two UH-1Ys to the U.S. Marine Corps in February 2008. As of September 2009, the UH-1Y is in full-rate production, with the Marine Corps expected to have 21 by the end of the year. The Marine Corps plans to eventually buy 160 of the Y-models to replace their inventory of N-models, with aircraft deliveries to be completed by 2016.

Bell UH-1Y Venom Design

The UH-1Y variant modernizes the UH-1 design. Its most noticeable upgrade over previous variants is a four-bladed, all-composite rotor system designed to withstand ballistics up to 23 mm. A 21-inch (530 mm) insert just forward of the main door has been installed for more capacity. The UH-1Y features upgraded engines and transmission, a digital cockpit with flat panel multifunctional displays, and an 84% parts commonality with the AH-1Z. Compared to the UH-1N, the Y-model has an almost 125% increased payload, almost 50% greater range, a reduction in vibration, and higher cruise speed. The UH-1Y can keep up with the other helicopters it is escorting. The UH-1Y will have more power to maneuver. Ground forces commanders riding in the Y-model will have radios, firepower and the range to match the transport helicopters carrying their troops.

The Lockheed Martin target sight system (TSS) incorporates a third-generation FLIR sensor. The TSS provides target sighting in day, night or adverse weather conditions. The system has various view modes and can track with FLIR or by TV. It is also used on the AH-1Z Viper and the KC-130J Harvest HAWK.

MH-6 Little Bird

The MH-6 Little Bird (Killer Egg), and its attack variant AH-6, are light helicopters used for special operations in the United States Army. Originally based on a modified OH-6A, it was later based on the MD 500E, with a single five-bladed main rotor. The newest version, the MH-6M, is based on the MD 530F and has a single, six-bladed main rotor and four-bladed tail rotor.

The A/MH-6 was started in 1960, when the U.S. Army issued Technical Specification 153 for a Light Observation Helicopter (LOH) that could perform personnel transport, escort and attack missions, casualty evacuation, and observation. Twelve companies took part in the competition and Hughes Tool Company's Aircraft Division submitted the Model 369. Two designs, those submitted by Fairchild-Hiller and Bell, were selected as finalists by the Army-Navy design competition board, but the Army later included the helicopter from Hughes as well.

The first Model 369 prototype flew on 27 February 1963. Originally designated the YHO-6A under the Army's designation system, the aircraft was redesignated the YOH-6A under the Department of Defense's new joint system in 1962. Five prototypes were built, fitted with a 252 shp (188 kW) Allison T63-A-5A, and delivered to the U.S. Army at Fort Rucker, Alabama to compete against the other 10 prototype aircraft submitted by Bell and Fairchild-Hiller. In the end, Hughes won the competition and the Army awarded a contract for production in May 1965. The initial order was for 714 aircraft, but that was later increased to 1,300 with an option to buy another 114. Seventy helicopters were built in the first month.

This agile, unarmed helicopter is outfitted with outboard "benches" designed to ferry up to three commandos on each side. There is also a gunship variant, the AH-6. Painted black for nighttime operations, this small aircraft can conduct rapid insertions and extractions of special operations forces into areas its larger brother, the MH-60 Black Hawk, cannot.

Variants

AH-6C

Special Forces attack version. Modified OH-6A to carry weapons and operate as a light attack aircraft for the 160th SOAR(A).

EH-6E

Special Forces electronic warfare, command-post version.

MH-6E

Improved attack helicopter used by US Army special forces units, and stealthy light attack and transport helicopter for US Army special forces units.

AH-6F

Special Forces attack version.

AH-6G

Special Forces attack version.

MH-6H

Special Forces version.

AH/MH-6J

Improved special forces transport and attack versions. Updated light attack helicopter based on the MD 530MG and equipped with an improved engine, FLIR, and a GPS/inertial navigation system.

AH/MH-6M

Also occasionally referred to as the Mission Enhanced Little Bird (MELB), it is a highly modified version of the MD 530 series commercial helicopter.

A/MH-6X

An AH/MH-6M MELB helicopter modified for use as a UAV. It builds upon experience gained through development of the Unmanned Little Bird (ULB) Demonstrator, which is a civil MD 530F modified for autonomous UAV flight. Boeing has announced that this version is marketed solely to other nations, not the U.S., for use as a low-cost attack helicopter.

Boeing AH-64 Apache

The Boeing AH-64 Apache is a four-blade, twin-engine attack helicopter with a tailwheel-type landing gear arrangement, and a tandem cockpit for a two-man crew. The Apache was developed as Model 77 by Hughes Helicopters for the United States Army's Advanced Attack Helicopter program to replace the AH-1 Cobra, and was first flown on 30 September 1975. The AH-64 was introduced to US Army service in April 1986. The AH-64 Apache features a nose-mounted sensor suite for target acquisition and night vision systems. It is armed with a 30-millimeter (1.2 in) M230 Chain Gun carried between the main landing gear, under the aircraft's forward fuselage. It has four hardpoints mounted on stub-wing pylons, typically carrying a mixture of AGM-114 Hellfire missiles and Hydra 70 rocket pods. The AH-64 has a large amount of systems redundancy to improve combat survivability. The U.S. Army selected the AH-64, by Hughes Helicopters, over the Bell YAH-63 in 1976, and later approved full production in 1982. McDonnell Douglas continued production and development after purchasing Hughes Helicopters from Summa Corporation in 1984. The first production AH-64D Apache Longbow, an upgraded version of the original Apache, was delivered to the Army in March 1997. Production has been continued by Boeing Defense, Space & Security; over one thousand AH-64s have been produced to date. The U.S. Army is the primary operator of the AH-64, it has also become the primary attack helicopter of multiple nations, including Greece, Japan, Israel, the Netherlands and Singapore; as well as being produced under license in the United Kingdom as the AgustaWestland Apache. U.S. AH-64s have served in conflicts in Panama, the Persian Gulf, Kosovo, Afghanistan, and Iraq. Israel has made active use of the Apache in its military conflicts in Lebanon and the Gaza Strip, while two coalition allies have deployed their AH-64s in Afghanistan and Iraq.

The AH-64 Apache has a four-blade main rotor and a four-blade tail rotor. The crew sits in tandem, with the pilot sitting behind and above the copilot/gunner. The crew compartment has shielding between the cockpits, such that one crew member can survive hits. The compartment and the rotor blades are designed to sustain a hit from 23-millimeter (0.91 in) rounds. The airframe includes some 2,500 pounds (1,100 kg) of protection against ballistic strikes. The Apache also utilizes a self-sealing fuel system to protect against the loss of fuel caused by ballistic projectiles. The AH-64 is powered by two General Electric T700 turboshaft engines with high-mounted exhausts on either side of the fuselage. Various models of engines have been used on the Apache, those in British service use engines from Rolls-Royce instead of General Electric. In 2004, General Electric Aviation began producing more powerful T700-GE-701D engines, rated at 2,000 shp (1,500 kW) for AH-64Ds. One of the revolutionary features at the introduction of the Apache was its helmet mounted display, the Integrated Helmet and Display Sighting System (IHADSS), among other abilities the pilot or gunner can slave the helicopter's 30 mm automatic M230 Chain Gun to his helmet, making the gun track head movements to point at where he looks. The M230E1 can be alternatively fixed to a locked forward firing position, or controlled via the Target Acquisition and Designation System (TADS).

The AH-64 is designed to endure front-line environments and to operate during the day or night and in adverse weather using avionics, such as the Target Acquisition and Designation System, Pilot Night Vision System (TADS/PNVS), passive infrared countermeasures, GPS, and the IHADSS. A newer system that is replacing TADS/PNVS is Arrowhead (MTADS); it is manufactured by Lockheed Martin, a contract was made on 17 February 2005 to begin equipping all models of American Apaches. The AH-64 is adaptable to numerous different roles within its context as Close Combat Attack (CCA), and has a customizable weapons loadout for the role desired.[38] In addition to the 30-mm M230E1 Chain Gun, the Apache carries a range of external stores on its stub-wing pylons, typically a mixture of AGM-114 Hellfire anti-tank missiles, and Hydra 70 general-purpose unguided 70 mm (2.76 in) rockets. The Stinger and AIM-9 Sidewinder air-to-air missiles and the AGM-122 Sidearm anti-radiation missile were evaluated beginning in the late 1980s. The Stinger was initially selected over the AIM-9, but the US Army is considering the Starstreak air-to-air missile instead. The stub-wing pylons also have mounting points for use during ground helicopter maintenance; though in case of emergency the mount points can be used for harnessing personnel to the wings during transport. External fuel tanks can also be carried by the pylons to increase range and mission time. For rapid deployment and transport around the world, six AH-64 Apaches can be safely fitted inside the cargo hold of a USAF Lockheed C-5 Galaxy.