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ARH-70 Arapaho
An ARH-70 arriving at Cairns Army Airfield, Alabama
Role Armed reconnaissance helicopter
Manufacturer Bell Helicopter
First flight 20 July 2006
Status Canceled
Number built Four (prototypes)
Developed from Bell 407

The Bell ARH-70 Arapaho[1][2] is a four-bladed, single-engine, light military helicopter designed for the United States Army's Armed Reconnaissance Helicopter (ARH) program. With a crew of two and optimized for urban combat, the ARH-70 was slated to replace the Army's aging OH-58D Kiowa Warrior. Excessive delays and growth in program costs forced its cancellation on 16 October 2008, when the Department of Defense failed to certify the program to Congress. The ARH-70 was touted as having been built with off-the-shelf technology; the airframe was based on Bell's commercially successful Bell 407.


On 23 February 2004, the U.S. Army announced their decision to cancel the RAH-66 Comanche helicopter program. The program had cost US$6.9 billion and 20 years of development without fielding a production aircraft. The cancellation was a result of a six-month Army study directed by Army Chief of Staff General Peter Schoomaker. The study recommended that by canceling the program before the Comanche reached production, the Army could save US$14 billion which could then be used to update and replace the aging airframes of the current fleet.[3]

The OH-58D Kiowa Warrior was targeted by the study for replacement in the active service fleet, based on the age of the airframe, recent losses, and the lack of replacement airframes. The Army developed an armed reconnaissance helicopter concept that would use commercial off-the-shelf (COTS) technology, with a goal of an operational unit of 30 helicopters and eight trainers ready by September 2008.[4] On 9 December 2004, Army officials issued a request for proposals (RFP) for the ARH.[5] Two companies submitted bids:[6]

  • Boeing proposed the upgraded version of the MH-6 Little Bird, the MH-6M Mission Enhanced Little Bird (MELB). Because the aircraft was already in service with the 160th Special Operations Aviation Regiment, it became the predictive favorite despite doubts that MD Helicopters Inc. (MDHI) could ramp up production to meet the contract's demands. To alleviate this concern, Boeing purchased the production rights for the design and served as the prime contractor.[7]

A Bell 407 being used for early development of the ARH-70

  • Bell Helicopter proposed an update of the OH-58D concept in a militarized version of the Bell 407, using a more powerful Honeywell HTS900 turboshaft engine,[8] an all-composite main rotor based on the Bell 430's rotor, and the Bell 427 tail assembly.[9]

On 29 July 2005, the Army announced Bell as the winner of a contract for 368 helicopters. There was some confusion as Bell figures placed the contract value at US$2.2 billion while Army estimates were over US$3 billion, compared to its earlier estimate of US$2.36 billion.[10] The contract called for the development of prototypes and the delivery of pre-production aircraft to the Army for the Limited User Test (LUT), with the first unit equipped by the end of September 2008.[4][11]

Flight test program

Bell's ARH demonstrator, a modified Bell 407 (s/n 53343/N91796 [12] ), first flew on 3 June 2005.[13] In February 2006, the ARH demonstrator flew with a limited avionics and Mission Equipment Package (MEP), and in April, Bell fitted and mounted the Honeywell HTS900-2 engine to the demonstrator airframe, followed by a series of ground runs.[14] The first flight of the ARH-70 occurred on 20 July 2006, at Bell's XworX facility in Arlington, Texas.[4] The flight had been delayed, first in March and then in May, to allow Bell to configure the prototypes as pre-production aircraft. Bell and the Army both eventually agreed that this delay would be essential for maintaining the compressed timeline for development.[14] On 21 February 2007, during its maiden flight, prototype #4 (s/n 53906/N445HR) suffered a loss of engine power, due to fuel starvation, and made an autorotational landing at a nearby golf course. The aircraft was damaged beyond repair when it rolled over during the landing, but the test pilots survived and were not injured.[15][16][17]

Program cost problems

A month later, on 22 March 2007, the Army issued a "Stop Work" notice, giving Bell thirty days to come up with a plan to get the ARH program back on track. Previous estimates for the System Development Demonstration portion of the program had grown from $210 million to over $300 million.[18] Textron, Bell's parent company, notified investors that they could lose $2–4 million on each aircraft under the contract.[19] Bell appealed and received permission to continue development using company funds until the notice was resolved. On 18 May 2007, the Army approved continuation of the ARH program.[20]

On 25 July 2007, the House Appropriations Committee’s Defense panel drafted a bill for the 2008 Defense Budget which zeroed out funding for ARH-70 production, citing Bell's inability to enter production, but continued funding for research and development.[21] However, in January 2008, government officials began working on export policy to allow international sales of the ARH-70. Including the U.S. Army's expected total of 512 helicopters, orders were anticipated to total over 1000.[22]

The Army filed a Nunn-McCurdy cost and schedule breach on 9 July 2008, when new cost estimates showed a 40% cost increase above initial estimates. In August 2008, the Army requested that Bell cease hiring workers for the ARH-70 program pending the outcome of the Nunn-McCurdy review.[23]


On 16 October 2008, the Army's Acquisition Executive Office for Aviation directed that the ARH contract be terminated completely for the convenience of the government.[24] The cancellation was the result of the United States Department of Defense (DOD) not certifying the US$6.2 billion ARH-70 program to Congress. John Young, the Undersecretary of Defense for Acquisition, Technology and Logistics, cited the reason as excessive costs of the program which had increased over 70 percent with an estimated per-unit cost of US$14.5 million, up from US$8.5 million.[25]

Specifications (ARH-70)

Data from Bell ARH-70,[26] Bell 407[27]

General characteristics

  • Crew: 2 pilots
  • Capacity: six passengers
  • Length: 34 ft 8 in (10.57 m)
  • Rotor diameter: 35 ft 0 in 35 (10.67 m)
  • Height: 11 ft 8 in (3.56 m)
  • Disc area: 962 ft² (89 m²)
  • Empty weight: 2,598 lb (1,178 kg)
  • Loaded weight: 5,000 lb (2,268 kg)
  • Useful load: 1,868 lb (847 kg)
  • Max. takeoff weight: 5,000 lb (2,268 kg)
  • Powerplant: 1 × Honeywell HTS900-2 turboshaft, 970 shp (723 kW)


  • Maximum speed: 140 kts (161 mph, 259 km/h)
  • Cruise speed: 113 kts (130 mph, 209 km/h)
  • Range: >162 nmi (186 miles, 300 km)
  • Service ceiling: 20,000 ft (6,096 m)


See also


  1. U.S. Army Happier With ARH-70A Program
  2. Aviation Modernization Program to Field Lakota, Modify Current Helos
  3. Burlas, Joe. "Comanche project grounded". Army News Service. 23 February 2004. Accessed on 17 October 2008.
  4. 4.0 4.1 4.2 "ARH-70A First Flight!". Bell Helicopter press release, 20 July 2006. Accessed 17 October 2008.
  5. "Armed Reconnaissance Helicopter (ARH)". Global Security. Accessed 1 October 2007.
  6. "Filling Comanche's Shoes". Aviation Today
  7. "Rotorcraft Report: Bell Beats Boeing, Aims for ARH Deliveries Next Year". Rotor & Wing, September 2005. Accessed 17 October 2008.
  8. Trimble, Stephen. "Bell and Boeing battle to win ARH". Flight International, 22 February 2005.
  9. Warwick, Graham. "Bell launches Honeywell HTS900-powered 417 to rival Eurocopter Squirrel". Flight International, 27 February 2006.
  10. "Bell defeats Boeing with 407 ARH". Flight International. 9 August 2005. Accessed 18 October 2008.
  11. The Bell ARH-70A, Armed Reconnaissance Helicopter - Program Timeline. Bell Helicopter. Accessed 26 September 2010.
  12. 407 airframe
  13. "ARH debut". Flight International. 14 June 2005. Accessed 18 October 2008.
  14. 14.0 14.1 "Rotorcraft Report". Rotor & Wing. April 2006. Accessed on 18 October 2008.
  15. "NTSB Identification: DFW07CA066". factual report. National Transportation Safety Board. 29 May 2007. Accessed on 18 October 2008.
  16. "ARH Crash: Foreign Objects Blocked Fuel Flow". Rotor & Wing. Aviation Today. 29 March 2007. Accessed 17 October 2008.
  17. "ARH Crash Probe Clears Engine, Cites Fuel Starvation". Aviation Today. April 2008. Accessed 17 October 2008.
  18. Warwick, Graham. "Work stops as soaring ARH cost alarms Army". Flight. 27 March 2007. Accessed on 28 June 2009.
  19. "US Army orders Bell to stop work on ARH and come up with new pla"n. Flight International. Accessed 24 March 2007.
  20. "Army to Continue with Bell Helicopter/Textron Inc. for Armed Reconnaissance Helicopter". Army press release. United States Army. 18 May 2007.
  21. United States House of Representatives. "Selected Cuts". Summary: 2008 Defense Appropriations. United States House of Representatives. 2008. Accessed on 28 June 2009.
  22. "Daily News: Army Requests Hundreds of ARH-70As". Rotor & Wing magazine, 23 January 2008.
  23. Bruno, Michael and Graham Warwick. "ARH Breaches Nunn-McCurdy Caps". Aviation Week. 10 July 2008. Accessed 28 June 2009.
  24. Army Press Service. "Armed Reconnaissance Helicopter program halted, need for capability remains". Army News. 17 October 2008. Accessed on 24 October 2008.
  25. "Pentagon Cancels Armed Reconnaissance Helicopter". Defense News, 16 October 2008. Accessed 16 October 2008.
  26. Bell ARH-70 page
  27. Bell 407 specifications page

External links

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