Bell ARH-70 (Arapaho)

History

The Bell ARH-70 helicopter was developed for the U.S. Army as a potential drop-in replacement for the successful but aging Kiowa Warrior series of lightly armed reconnaissance aircraft. To keep production and acquisition costs for the U.S. Army low, the program seeks to develop products using existing but proven components.

Out of this requirement, the Bell ARH is essentially a militarized version of the successful Bell 407 civilian product. The new helicopter system is visually similar to the OH-58D Kiowa Warrior it is intended to replace. Following the official retirement of the stealthy RAH-66 Comanche two-seater light attack helicopter, the ARH-70 appeared in the U.S.

Army's Armed Reconnaissance Helicopter (ARH) program. The initial production form will receive the designation ARH-70A.

RAH-66 Comanche

The RAH-66 Comanche embarrassed the US Army. The platform has now taken decades to develop, and there's very little to show. Some thought (and were right) that continuing to support the program - no matter how promising it was on paper - would only be financially overrun.

As a result, the young program was canceled in 2004 in favor of upgrading the existing fleet of still-available platforms, such as the OH-58D Kiowa Warrior or the MH-6 Bird.

Call ended

In December 2004, the US Army issued a request with recommendations. Notable among the returns are the Bell 407 (touted as an upgraded OH-58 Kiowa Warrior) and the Boeing Response (essentially an upgraded MH-6 "Bird"). Bell eventually won and secured a multi-billion dollar production deal on July 29, 2005.

The contract called for approximately 368 production prototypes and required two prototypes and two pre-production samples, which were later changed to four prototypes with pre-production value.

ARH

The first flight of the demonstration ARH took place on June 3, 2005. Additional flights followed, culminating in additional avionics, mission-specific systems and Honeywell's choice of HTS900-2 turboshaft engines. So far, the engine has only been tested on demonstrators and on the ground to verify its basic qualities. After some planning delays, the first "true" ARH-70 prototype (Prototype #2) made its maiden flight on July 20, 2006, less than a year before the Army contract was awarded.

Prototype #4 was notable for being forced to crash at the Golden Stadium following a documented engine failure on February 21, 2007. Although no pilots were injured in the crash, the airframe is considered a complete loss and setback for the ARH program.

Balloon cost

Ultimately, the ARH-70 soon had delays and product costs. The U.S. Army temporarily halted the program and gave Bell a month to rectify his behavior. Meanwhile, Bell continued to develop these systems with its own resources until the U.S. Army agreed to resume the program in mid-2007.

Rising costs have forced DoD to conduct automatic and direct review of programs under the McCurdy Act. In the 2008 defense budget, there was no appropriation to support ARH-70. Last attempts to offer the ARH-70 as an export product to recover the cost have failed, and the ARH-70 is temporarily in limbo.

At some point, the U.S. military alone is expected to purchase about 512 systems, with additional examples beyond the initially agreed total being made available to the Army National Guard to replace their older AH-64 Apaches.

End of the street

The ARH-70 program proved to be a very viable option for the US Army, although the mount met all required performance parameters. The Army Aviation Acquisition Executive Office is calling for the complete cancellation of DoD contracts. The Department of Defense officially approved the request without sponsoring millions of dollars in spending to the U.S. Congress, effectively ending Bell and her new little machine's hopes. By then, the unit cost of a single ARH-70 example had nearly doubled to an estimated $14. $5 million.

According to Bell, at the time of termination on October 16, 2008, the contract was 53 percent complete, recording approximately 1,500 flight test hours.

ARH-70 walks

The design of the ARH-70 follows the example of the OH-58 family of light helicopters. The two crew members sat side by side in front of the fuselage. Each position has redundant controls and a large clear curved front windshield for excellent visibility. Each pilot retains their own car-style door, hinged forward at two points for entering and leaving their respective cockpit seats. Optical and special mission equipment can be mounted on the outside of the "chin" part of the fuselage.

The cabin is located directly behind the cockpit and is accessed through a side door. The gun pylon protrudes from the bottom of the hull and can carry limited ammunition for attack. The landing skid is mounted on the bottom of the fuselage and supported at two fixed points.

The single engine is mounted high on the fuselage, above and behind the crew compartment. Exhaust gas is sprayed upwards at the rear of the engine compartment. The engine drives a four-blade main rotor and a two-blade tail rotor. The rear wing is raised in the rear of the crew compartment and engine compartment and is covered by a tall vertical fin.

Additional vertical fins were placed along the sides of the tail system in the horizontal plane. The tail rotor is set to face the port side of the aircraft.

The crew in the forward cockpit can accommodate two pilots and the main cabin can accommodate up to six passengers.

Engine

The ARH-70 is powered by a Honeywell HTS900-2 turboshaft engine producing 970 shp. The engine can provide the airframe with a top speed of 161 mph and a cruising speed of about 130 mph. She has a reported range of 186 miles with a service cap of 20,000 feet.

Curb weight is 2,598 lbs and maximum takeoff weight is 5,000 lbs.

Armed

As an armed reconnaissance helicopter, like the OH-58D before it, the ARH-70 is designed to carry a considerably smaller array of weapons. Primary strike power will be provided by 1 x GAU-19 .50 caliber Gatling cannon and Hydra 70 2.75 in (70 mm) rocket (also on an outboard mast) mounted on an outboard pylon.

Additional attack/defense is provided by crew-operated small arms that can be deployed by passengers in the cabin.

Arapaho Name

Although referred to as "Arapaho" in some official media reports, this name was never officially assigned to the ARH-70 product.

Specification

Basic

Production

Roles

Dimensions

Weight

Performance

Performance

Armor

Changes