Military, Products, Services

Renewed Lifeline for the Kiowa Warrior

By By Douglas Nelms | December 1, 2011
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A2D conversions will help the Army maintain its fleet of 368 OH-58 Kiowa Warriors by replacing helicopters lost in combat. Bell Helicopter

Combat is hard on helicopters, a known fact. It is particularly hard on those tasked to get down low to find the bad guys. As a result, aircraft attrition occurs through both accidents and enemy action. To alleviate those losses, Textron division Bell Helicopter and the U.S. Army are making progress with a Wartime Replacement Aircraft (WRA) program designed to replace the Army’s lost armed reconnaissance helicopters by taking OH-58A Kiowa cabins for conversion into OH-58D variants. Known as the ‘A2D’ program, the conversion is needed in order to take the U.S. Army back to its requirement for 368 Kiowa Warriors, and is a combined effort between Bell, the Armed Scout Helicopter Program Office, and the Corpus Christi Army Depot (CCAD).

The WRA program is completed in four phases. In Phase 1, an OH-58A model Kiowa is stripped down at the Aviation Forward Maintenance Activity (AFMA) in San Angelo, Texas. Phase 2 involves CCAD preparing the cabin for induction into the production line by conducting structural analysis and repairs. In Phase 3, Bell—through its Military Aircraft Assembly Center in Amarillo, Texas—converts the cabin from an A model to a D. The company also installs the wiring harness, fuel cells, instrument panel, firewalls, flight controls, environmental system and other structures. In Phase 4, CCAD repopulates all the components and returns the aircraft to flight.


Turnaround time per aircraft from entry into the program until returning to the Army will initially be two years—six months spent dedicated to stripping down the aircraft, 12 months for the conversion and six months for final assembly and post-production modifications. According to Bell, the time period is expected to “shorten up considerably” as experience is gained.

The WRA program is part of a three-pronged effort to resolve the issue of an increasingly aged fleet of scout helicopters. The OH-58A was developed in the early 1960s and deployed to Vietnam in 1969. Since then, “A” and “C” models have been converted into “D” under the Army Helicopter Improvement Program (AHIP).

While Bell did build an OH-58B model for sale to foreign militaries, there were no OH-58Bs delivered to the U.S. Army, according to an Army spokesman.

Initially, the OH-58D was just an unarmed, upgraded “C” model, introduced to the Army in 1985. However, beginning with production of the 202nd “D” model in May 1991, all OH-58Ds were produced in the armed Kiowa Warrior configuration. Bell was then contracted in January 1992 to retrofit all the remaining OH-58Ds into the Kiowa Warrior.

Bell delivered the first OH-58A dedicated to the program in June 2011, and CCAD handed over that initial aircraft to the Army’s 1st Combat Aviation Brigade, 1st Infantry Division in late October. The second cabin is set for delivery to CCAD by the end of 2011, with a production schedule of one per month starting in March 2012.

The current contract covers 18 cabins, with options for up to 66 cabins in future years. Overall cost for the 18 aircraft cabins is $76.2 million, which does not include post-production modifications and final assembly.

The A2D program is an interim effort to keep the Army at its required fleet of 368 Kiowa Warriors. In October 2010, the Army contracted for eight cabins plus three options for additional cabins, with a total ceiling of 66. The first option was awarded in August 2011 under a contract for 10 OH-58 cabins, accounting for the current order for 18. The two additional options are scheduled to be exercised using FY2012 and FY2013 appropriations.

There are currently OH-58As available for the A2D program to fill requirements under the second and third contract options, according to Lt. Col. Matthew Hannah, Kiowa Warrior product manager. Bell initially built some 2,200 OH-58s, of which there are still 114 in the active Army, including 55 OH-58Cs and 34 OH-58As within TRADOC (training and doctrine) units and 25 OH-58Cs in non-TRADOC units. The National Guard Bureau has an additional 117.

The A2D conversion provides a thicker mil skin and upgrades the aircraft from the 317-shp Allison T63A-700 on the A variant to the Rolls-Royce RR250-C30R/3 rated at 650 shp. This allows an increase from 3,500 to 5,500 lbs MGW.

As an alterative within the contract, the Army can exercise a “new metal” option instead of the conversion cabins. This would replace the conversion process with a new production cabin for a lower cost and more efficient production process. Bell built 39 new production OH-58Ds for Taiwan in the late 1990s. The company plans to submit a proposal to execute the option for new metal later this year.

Hannah said that new metal cabins “provide a capability to resolve the Kiowa Warrior fleet’s many issues with overuse and age, and also provide an efficiency path for upgrades in concert with OSD [Office of the Secretary of Defense] guidance.”

In describing the Army’s plan to revitalize its reconnaissance helicopter fleet, Hannah noted that there are three general approaches available. These include rebuilding current helicopter models, upgrading current platforms or procuring new models. The Army’s approach to solving its aging OH 58D Kiowa Warrior problem involves all three—beginning with WRA.

The second program in the Army’s reconnaissance helicopter fleet enhancement efforts is the OH-58F cockpit and sensor upgrade program (CASUP) that will add new technology to the OH-58D, transforming it into the OH-58F. The Army, as lead systems integrator, has already begun this program, with the first aircraft scheduled for delivery in FY16 (See Rotor & Wing, May 2011, page 22).

One key element of the OH-58F program is moving the mast-mounted sight down to the nose. Mike Miller, Bell’s director of business development and former Army experimental test pilot, said moving the mast-mounted sight “provides greater situational awareness to the pilots. They can now look under and close in to the aircraft. So when you’re flying over [the enemy] and they pop up and try to shoot you with an AK-47, you can’t see that with a mast-mounted sight, but you can with the nose-mounted sight.”

The nose-mounted sight will be the Raytheon-built common sensor payload (CSP) with next generation acquisition and targeting systems. The F model will also have three large color displays in the cockpit. Other improvements include a dual-channel FADEC engine control and a new computer processor, going from a CDS 4 to a CDS 5 operating system to increase both speed and capabilities.

The final program in the Army’s efforts to provide combat units with an armed reconnaissance aircraft will be the projected Armed Aerial Scout (AAS) helicopter. Bell currently has a company-funded program in progress to develop an advanced OH-58 aircraft—the OH-58 Block II—designed to meet the anticipated Army’s requirement for the AAS. A prototype aircraft has already completed “hot/high” trials, hovering out of ground effect at “6K/95,” or 6,000 feet at 95 degrees F, above a max gross weight of 5,500 lbs.

Miller noted that the new “6K/95” requirement is being applied to all of the Army’s new helicopter programs—the AH-64D Block III, UH-60M and CH-47F—based on the extreme conditions mission commanders are finding in both Iraq and Afghanistan.

Bell is putting in a more powerful Honeywell HTS900 engine (1,021 shp) into the Block II aircraft with a new tail rotor, new transmission and blades, Miller explained.

The Block II concept is to build on the funded F model program and provides a “menu of options” for upgrading performance. He added that in today’s budget environment “the Army needs a low-cost, low-risk path forward with its armed reconnaissance mission, while maintaining research dollars for future programs such as Joint Multi Role,” or JMR.

The WRA program is addressing the replacement requirement, while the OH-58F CASUP program is addressing the service life, or obsolescence situation. As for improving the performance needs, Miller said that the new OH-58 Block II would allow the Army to “pick off the menu” as the budget allows.

“If the budget would facilitate a new engine, we can put a new engine on the aircraft,” he explained. “Maybe the following year the budget will facilitate a new transmission, so we can put a new upgraded transmission on the aircraft. If the budget will facilitate the whole Block II upgrade, we can do that.” Miller said that his job is to make the customer successful, which for Bell means laying out a strategy that provides the Army with a whole menu to meet its requirements and budget.

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