Bell AH-1Z Viper
The Bell AH-1Z Viper is an American twin-engine attack helicopter, based on the AH-1W SuperCobra, that was developed for the United States Marine Corps as part of the H-1 upgrade program. The AH-1Z features a four-blade, bearingless, composite main rotor system, uprated transmission, and a new target sighting system. The AH-1Z, one of the latest members of the prolific Huey family, is also called "Zulu Cobra", based on the military phonetic alphabet pronunciation of its variant letter.
|An AH-1Z of the USMC|
|National origin||United States|
|First flight||8 December 2000|
|Introduction||30 September 2010|
|Primary user||United States Marine Corps|
|Developed from||Bell AH-1 SuperCobra|
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 programEdit
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 tailboom, engines, rotor system, drivetrain, 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 the United States Navy's 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 late 2006 NAVAIR awarded a contract to Meggitt Defense Systems to develop a new linkless 20 mm ammunition handling system to improve on the gun feed reliability of the existing linked feed system. These systems are now being retrofitted into the AH-1W and AH-1Z fleets with good results during combat in Afghanistan.
In February 2008, the U.S. Navy adjusted the contract so the last 40 AH-1Zs are 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 planned to order 189 AH-1Zs with 58 of them being new airframes, with deliveries to continue until 2022. On 10 December 2010, the Department of the Navy approved the AH-1Z for full-rate production.
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 wingtip 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 AN/APG-78 Longbow fire control radar can also be mounted on a wingtip 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 8×6-inch multifunction liquid crystal displays (LCD) and one 4.2×4.2-inch dual function LCD. 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 Meggitt's 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 laser spot 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 KC-130J Harvest HAWK.
The AH-1Z completed sea-trial flight testing in May 2005. On 15 October 2005, the USMC, through the Naval Air Systems Command, accepted delivery of the first AH-1Z production helicopter to enter the fleet. The AH-1Z and UH-1Y completed their developmental testing in early 2006. During the first quarter of 2006 the aircraft were transferred to the Operational Test Unit at the NAS Patuxent River, where they began operational evaluation (OPEVAL) testing.
In February 2008, the AH-1Z and UH-1Y began the second and final portion of OPEVAL testing. AH-1Z testing was stopped in 2008 due to issues with its targeting systems. The AH-1Z was later declared combat-ready on 30 September 2010.
In 2000, the Turkish Army selected the AH-1Z for procurement; this was later cancelled in 2004. In September 2012, the U.S. Congress was notified of the possible Foreign Military Sales (FMS) for 36 AH-1Z Vipers and associated equipment and weapons by South Korea. The Viper was competing against the Boeing AH-64 Apache and the TAI/AgustaWestland T129 ATAK for the order; a decision was expected by the end of 2012. In April 2013, South Korea announced the selection of the AH-64E.
In April 2015, the U.S. State Department approved a possible FMS sale to Pakistan for 15 AH-1Z Vipers with Hellfire missiles, associated equipment and support worth up to $952 million. Pakistan is to receive 9 AH-1Z helicopters by September 2018. Bell is also interested in selling the AH-1Z to Poland and Czech Republic, which are going to retire their Mil Mi-24s.
In November 2016, Bell Helicopter signed a memorandum of understanding with Romanian airspace company IAR – Ghimbav Brasov Group for potential collaboration on the AH-1Z Viper. In August 2017, Romania also signed a letter of intent with Bell Helicopter to establish a joint venture with Romanian state-owned ROMARM for the potential procurement of a number of AH-1Z helicopters.
In 2016, it was reported that the Royal Moroccan Air Force was interested in procuring the AH-1Z helicopters.
In July 2017, Bell Helicopter and Polish Armaments Group signed a letter of intent planning on cooperating on the UH-1Y and AH-1Z helicopters, forming a potential bid for the Polish Kruk attack helicopter acquisition program, part of a wider modernization effort.
In October 2017, Thailand's minister of Defence Prawit Wongsuwan stated that Thailand is looking onto replacing its fleet of ageing AH-1F Cobra attack helicopters, and will launch a procurement committee to look into the matter. Royal Thai Army officials have come out and said that the Army is looking into the Bell AH-1Z Viper, as well as the Agusta A129 Mangusta, Mil Mi-28, CAIC Z-10, Bell AH-1 SuperCobra and Boeing AH-64 Apache.
On 27 April 2018, the U.S. Defense Security Cooperation Agency announced it had received U.S. State Department approval and notified Congress of a possible sale to Bahrain of 12 AH-1Zs, 26 T-700 GE 401C engines, and armaments for an estimated cost of US$911.4 million. In November 2018, Bahrain confirmed the order for 12 AH-1Zs with deliveries to begin in 2022.
- Crew: two: pilot, co-pilot/gunner (CPG)
- Capacity: 6,661 lb (3,021 kg)
- Length: 58 ft 3 in (17.8 m)
- Rotor diameter: 48 ft (14.6 m)
- Height: 14 ft 4 in (4.37 m)
- Disc area: 1,808 ft² (168.0 m²)
- Empty weight: 12,300 lb (5,580 kg)
- Useful load: 5,764 lb (2,620 kg)
- Max. takeoff weight: 18,500 lb (8,390 kg)
- Rotor systems: 4 blades on main rotor, 4 blades on tail rotor
- Powerplant: 2 × General Electric T700-GE-401C turboshaft, 1,800 shp (1,340 kW) each
- Never exceed speed: 222 knots (255 mph, 411 km/h) in a dive
- Cruise speed: 160 kt (184 mph, 296 km/h)
- Range: 370 nmi (426 mi, 685 km)
- Combat radius: 125 nmi (144 mi, 231 km) with 2,500 lb (1,130 kg) payload
- Service ceiling: 20,000+ ft (6,000+ m)
- Rate of climb: 2,790 ft/min (14.2 m/s)
- Guns: 1 × 20 mm (0.787 in) M197 3-barreled Gatling cannon in the A/A49E-7 turret (750 round ammo capacity)
- Hardpoints: Up to 6 pylon stations on stub wing
- Rockets: 2.75 in (70 mm) Hydra 70 or APKWS II rockets – Mounted in LAU-68C/A (7 shot) or LAU-61D/A (19 shot) launchers (up to 76 unguided or 28 guided rockets total)
Aircraft of comparable role, configuration and era
- Agusta A129 International / TAI/AgustaWestland T129
- Boeing AH-64 Apache
- CAIC Z-10
- Eurocopter Tiger
- HAL Light Combat Helicopter
- Harbin WZ-19
- Kamov Ka-50/Ka-52
- Mil Mi-28
- TAI/AgustaWestland T129
- AH-1Z. Helis.com
- "AH-1Z Viper enters production as substantially new aircraft". Flight Global. 2010-12-20.
- "Fiscal Year (FY) 2011 Budget Estimates, Aircraft Procurement, Vol. I, BA 1–4" (PDF). US: Department of the Navy. February 2010: 27.
- "4120-15L, Model Designation of Military Aerospace Vehicles" (PDF). US: Department of Defense. 12 May 2004.
- Bell AH-1Z page Archived March 28, 2007, at the Wayback Machine. Bell Helicopter. Retrieved 3 January 2008.
- Donald, David. Modern Battlefield Warplanes. AIRTime Publishing, 2004. ISBN 1-880588-76-5.
- Bishop, Chris. Huey Cobra Gunships. Osprey Publishing, 2006. ISBN 1-84176-984-3.
-  Archived 2013-12-17 at the Wayback Machine. Bell Helicopter, Retrieved: 16 July 2012.
- AH-1W/AH-1Z Super Cobra Attack Helicopter, USA. Airforce-Technology.com. Retrieved: 14 January 2008. Archived March 16, 2008, at the Wayback Machine[unreliable source?]
- "AH-1Z completes first flight". Bell Helicopter, 7 December 2000.
- "AH-1Z/UH-1Y complete developmental testing". US Navy, 6 March 2006.
- Warwick, Graham. "Bell AH-1Z upgrade to switch to new airframes". Flightglobal.com, 15 February 2008.
- Trimble, Stephen. "US Navy proposes more UH-1Ys, AH-1Zs despite test phase setback". Flight International, 22 August 2008.
- Butler, Amy. "U.S. Marines Propose AH-1Z Production Boost"[dead link] Aviation Week, 13 October 2010. Retrieved: 13 October 2010.
- Bell to finish Marine Corps deliveries of UH-1Y Venom by end of 2018. Flight International. 17 May 2018.
- "Bell Helicopter AH-1Z earns Navy approval for full rate production". Shephard Group Limited. 10 December 2010. Archived from the original on December 16, 2010. Retrieved 11 December 2010.
- "Snakes and Rotors: The USMC's H-1 Helicopter Program". Defense Industry Daily. 30 December 2010. Archived from the original on 14 February 2011. Retrieved 2 January 2011.
- AN/APG – Equipment Listing. designation-systems.net
- Cpl. Samantha H. Arrington. "From Hueys to Harvest Hawk: Ordnance Marine arms aircraft in Afghanistan". DVIDS. 19 May 2011.
- "AH-1Z/UH-1Y complete first sea trials", US Navy, 13 June 2005. Archived February 15, 2008, at the Wayback Machine
- "Bell 449 SuperCobra and KingCobra". Jane's Information Group, 7 December 2005. Archived December 27, 2008, at the Wayback Machine
- Milliman, John. "AH-1Z/UH-1Y complete developmental testing" Archived 2011-07-28 at the Wayback Machine. US Navy, 1 March 2006.
- "AH-1Z/UH-1Y Start OPEVAL". US Navy, 6 May 2006.
- Warwick, Graham. "US Marine Corps' Bell AH-1Z and UH-1Y enter final test phase". Flightglobal.com, 20 February 2008.
- Trimble, Stephen (30 September 2010). "USMC declares AH-1Z Viper combat ready". Flight International. Archived from the original on 7 October 2010. Retrieved 1 October 2010.
- "AH-1W / AH-1Z Super Cobra Attack Helicopter, United States of America". Army-technology.com[unreliable source?]
- "Korea – 36 AH-1Z Cobra Attack Helicopters". Pacificsentinel.com, 26 September 2012.
- Korea helicopter bids. Flightglobal.com, 26 September 2012.
- Song, Sang-ho (17 April 2013). "Seoul to Purchase 36 Apache Helicopters". Korea Herald.[unreliable source?]
- Ansari, Joe Gould, Usman (8 August 2017). "State Dept. OKs $952M Pakistan Helo Deal". Defense News. Retrieved 9 February 2019.
- "US okays attack helicopters, hellfire missiles for Pakistan under $1 billion sale". Daily Times. 2015. Archived from the original on 10 April 2015. Retrieved 7 April 2015.
- "Pakistan to receive nine AH-1Z attack helos". IHS Janes, 5 April 2016.
- "Pakistan orders nine more Bell AH-1Z gunships". Flight Global, 5 April 2016.
- "Vipers for V4" (in Polish). Polska Zbrojna. 2016. Retrieved 25 February 2016.
- Woodward, Andrew (14 November 2016). "Bell Helicopter signs Memorandum of Understanding with IAR – Ghimbav Brasov". Bell Helicopter. Fort Worth, Texas. Retrieved 15 November 2016.
- "Romania signs LoI with Bell Helicopter for attack helicopters". Airforce Technology. 10 August 2017. Archived from the original on 23 August 2017. Retrieved 23 August 2017.
- "Romania, Bell Helicopter sign LOI for AH-1Z Viper combat helicopter acquisition". Air Recognition. 9 August 2017. Archived from the original on 23 August 2017. Retrieved 23 August 2017.
- "L'hélicoptériste américain Bell cherche à vendre son ultime cobra aux Forces armées royales". Le Desk. 2016-04-14. Retrieved 2017-05-26.
- Airbus Optimistic On Australia’s Tigers As Bell, Boeing Circle March 1, 2017 Aviation Week Retrieved March 5, 2017
- Tomkins, Richard (26 July 2017). "Bell, PGZ to cooperate on military helicopters for Poland". United Press International. Archived from the original on 23 August 2017. Retrieved 23 August 2017.
- Nicholas, Scott (27 July 2017). "Textron Subsidiary, PGZ to Cooperate on AH-1Z, UH-1Y Helicopter Offerings for Poland". Executive Biz. Archived from the original on 23 August 2017. Retrieved 23 August 2017.
- Fuller, S.L. (27 July 2017). "Bell Signs Letter of Intent with Polish Firm for UH-1Y, AH-1Z". Rotor and Wing International. Archived from the original on 23 August 2017. Retrieved 23 August 2017.
- Grevatt, Jon (10 October 2017). "Thailand plans combat helicopter acquisition". IHS Jane's 360. Archived from the original on 10 October 2017. Retrieved 10 October 2017.
- "Bahrain – AH-lZ Attack Helicopters". US DSCA. 27 April 2018. Retrieved 30 April 2018.
- Morrison, Murdo (15 November 2018). "Bahrain confirms purchase of 12 AH-1Z Vipers". Flight Global. Bahrain. Archived from the original on 15 November 2018. Retrieved 15 November 2018.
- "Bell's Venom and Viper helos court foreign sales interest". Flight Global, 20 May 2016.
- "World Air Forces 2013" (PDF). Flightglobal Insight. 2013. Retrieved 12 February 2013.
- Frawley, Gerard: The International Directory of Military Aircraft, p. 37. Aerospace Publications Pty Ltd, 2002. ISBN 1-875671-55-2.
- BAE’s APKWS rockets integrated on Bell’s new Model 407GT – Flightglobal.com, March 5, 2013
- Bell's Venom and Viper helos court foreign sales interest – Flightglobal.com, 20 May 2016