The U.S. Army is rapidly using up its fleet of OH-58D Kiowa Warrior attack helicopters, which are loved by soldiers but sometimes seem inadequate for hot temperatures and high mountainous territory in Afghanistan.
“We’re working hard to rebuild damaged aircraft and to upgrade existing ones,” said Lt. Col. Scott Rauer, product manager at the Corpus Christi Army Depot in Texas. “I don’t think anyone doubts that eventually there will have to be a replacement.”
“Under the skin the Kiowa Warrior is a civilian Bell JetRanger of 1967 vintage meant to have two rotor blades and a certain amount of power,” said retired Maj. Kurt Warner, who flew the OH-58D in Iraq. “The engine and transmission are too much for the airframe and the rivets tend to work themselves out.” But Warner added that the OH-58 performs better at heights than it is given credit for.
“I don’t have a lot of bad things to say about it,” said Warner. “The aircraft acquitted itself well with me when I was in Iraq. It works well supporting troops on the ground and gives you long loiter time over the battlefield. You fly it and it keeps going. You park it for too long and the old bones don’t sit too well. Those bones like to fly.”
The Army has 330 Kiowa Warriors in inventory but says it needs 368. The service is losing five OH-58s each year that are not being replaced. Kiowa Warriors have flown 630,000 combat hours. At an average of 90 flying hours per month per airframe, the OH-58D has the highest operations tempo of any Army aviation platform.
The Kiowa Warrior dates back to the Reagan era. Bell Aircraft Corp. started flight tests in March 1983 of a civilian LongRanger III, modified with the 650 shaft horsepower Allison (now Rolls-Royce) T703-A-720 turboshaft engine and the 33-foot, 4-inch four-bladed main rotor and composite tail rotor later found on production Kiowa Warriors. The first of five OH-58D Aeroscout prototypes flew at Bell’s Arlington, Texas facility on Sept. 1, 1983. The first production OH-58D was delivered in March 1986, a time when the Army had plenty of dollars and wanted (then) to obtain 578 aircraft by 1991. All OH-58Ds initially were remanufactured OH-58As, but the notion of a mere “rebuild” may be insufficient. “We take the old helicopter and reduce it to a bare shell,” says Bell’s Orson Hurwell. “Then we chop off the tail boom and build a completely new one. We throw out the rotor and install a new rotor. We put in a different drive train, a different engine, a different tail rotor. It’s, like, a 90 percent new aircraft.” At the Army’s request, Bell is now re-opening its production line to turn out at least 20 more OH-58F helicopters.
To cope with a fleet shortage and with the aging of the airframe, the Army is also converting some Kiowa Warriors to OH-58F standard, in its Cockpit and Sensor Upgrade Program (CASUP). “The F model Kiowa Warrior is a significant investment into the OH-58D fleet,” Col. Robert Grigsby, Army’s Armed Scout Helicopter program manager, told reporters in October. The OH-58F has an advanced nose mounted sensor, improved cockpit control hardware and software for enhanced situational awareness, three full color multi-function displays, dual-redundant digital engine controller for enhanced engine safety, digital inter-cockpit communications, digital AGM-114 Hellfire missile upgrades, and a redesigned aircraft wiring harness.
The Army is shaping an Analysis of Alternatives (AOA) for an OH-58D replacement. The service previously tried twice to field a new battlefield helicopter but was forced to cancel programs – the ambitious RAH-66 Comanche canceled in 2004 and the more utilitarian RAH-70A Arapaho scrubbed in 2008.
In a proposal the Army hasn’t acted on yet, Bell wants to replace the current OH-58D engine with the Honeywell HTS900-2, with about 50 percent more power. EADS North America is prepared to offer the Army an armed version of its UH-72A Lakota helicopter, while AgustaWestland is expected to offer a militarized variant of its AW119 and Boeing wants to submit the AH-6 “Little Bird,” which recently was ordered to replace OH-58s in Jordan.