The Bell OH-58 Kiowa is a single-engine, single-rotor military helicopter, designed for observation, utility, and direct fire support.
It was built by American company Bell Helicopter and shares similarities with the Model 206A JetRanger civilian helicopter.
Originally, the OH-58 was developed in the early 1960s as the D-250 for the Light Observation Helicopter (LOH). Even though the Hughes OH-6 Cayuse initially outperformed Bell’s submission in 1965, Bell refined its design, creating the Model 206A.
Design and Development
The Bell OH-58 Kiowa is a family of single-engine, single-rotor military helicopters mainly used for observation and support.
The original OH-58A’s main role was to identify targets, assisting platforms like the Bell AH-1 Cobra attack helicopter and ground artillery.
Lacking armaments, it could carry a small cargo or two passengers and weighed 1,451kg when fully loaded. Initially, crews conducted observations, but later models received sophisticated sensors for precise target location.
Subsequent models, like the OH-58D Kiowa, had increased payload capacities, designed to carry up to 2,495kg. Early Kiowas had a flexible twin-bladed main rotor, while starting with the OH-58D, a four-bladed rigid main rotor was used.
Composed entirely of composite materials, the OH-58D featured the first all-composite main rotor hub in the U.S. Army. Later models became light gunships, equipped with armaments like Stinger missiles and a .50-caliber machine gun.
Improvements also touched avionics and the cockpit, with new navigation and communication systems installed.
All light sources were redesigned for Night Vision Goggles (NVG) compatibility. Subsequent versions featured a glass cockpit, maintaining conventional instrumentation as a backup.
The OH-58D introduced the distinctive Mast Mounted Sight (MMS), looking like a beach ball above the rotor system.
Developed by Ball Aerospace & Technologies, the gyro-stabilized MMS houses a TV system, thermal imaging, and a laser range finder/designator.
This allows the OH-58D to acquire targets and provide laser designation in various conditions. Combined with the 1553 databus, the OH-58D, the first in the U.S. Army, could pass data directly to precision-guided weapons.
McDonnell Douglas Corp. developed the MMS, with production primarily in Monrovia, CA.
After mergers and sales, DRS Technologies now owns and manages the program, with various support located in California and Florida.
The OH-58F replaced the MMS with the AAS-53 Common Sensor Payload, mounted on the chin.
Operational OH-58s have knife-like extensions as part of the passive wire strike protection system, protecting against low altitude wire strikes.
This system, first tested on the OH-58, was adopted by the U.S. Army for many of their helicopters. Other defensive features included ballistic floor armor, missile warning systems, crashworthy seats, and infrared suppression systems for the engine exhaust.
Light Observation Helicopter
On 14 October 1960, the U.S. Navy, on behalf of the Army, sought proposals for a Light Observation Helicopter (LOH) from 25 manufacturers.
Bell Helicopter was among those approached and chose to participate, along with 12 others like Hiller Aircraft and Hughes Tool Co., Aircraft Division.
Internally, Bell called their design the D-250, later designated as the YHO-4.
On 19 May 1961, Bell and Hiller won the design competition. Bell evolved the D-250 into the Model 206, and the designation changed to YOH-4A in 1962.
This model, also known as the ‘Ugly Duckling,’ undertook its first flight on 8 December 1962. However, the Army preferred Hughes OH-6 Cayuse, selected in May 1965, over Bell’s and Fairchild-Hiller’s prototypes.
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After this rejection, Bell redesigned the aircraft for better aesthetics and functionality, naming the sleeker Model 206A the JetRanger.
In 1967, the Army requested new LOH bids as Hughes couldn’t meet production demands. Bell, resubmitting the 206A, won against Hughes, leading to the designation of OH-58A, named Kiowa in honor of the Native American tribe.
In the 1970s, the U.S. Army assessed the need to enhance their scout aircraft’s capabilities. They anticipated the replacement of the AH-1 by the AH-64A and considered an Aerial Scout Program.
The program aimed to develop advanced technology for night vision and precision navigation. The goals included long-range stabilized optical subsystems, computerized navigation, reduced detection signatures, and compatibility with attack helicopters.
In March 1974, a special task force at Fort Knox developed system requirements. By the next year, they had devised the requirements for an Advanced Scout Helicopter (ASH) program.
The program focused on rotorcraft capable of performing in various conditions and compatible with advanced weapon systems.
However, Congress didn’t provide funding in 1977, closing the ASH Project Manager’s Office on 30 September 1976.
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The program lingered as an unfunded requirement. On 30 November 1979, the decision was made to modify existing airframes. The development focused on a mast-mounted sight to improve reconnaissance, surveillance, and target acquisition.
Both the UH-1 and the OH-58 were evaluated, but the UH-1 was dropped due to its larger size. The OH-58 showed a dramatic reduction in detectability with a Mast-Mounted Sight (MMS).
On 10 July 1980, the Army decided the NTSH would be a competitive modification program, inspired by improvements in the commercial sector, such as Hughes Helicopters’ Hughes 500D.
Helicopter Improvement Program
The acquisition of NTSH led to the creation of the “Army Helicopter Improvement Program (AHIP)”. Bell Helicopter and Hughes Helicopters both restructured their scout aircraft to compete.
Bell presented an advanced version of the OH-58, their Model 406. Meanwhile, Hughes offered an upgraded OH-6. On 21 September 1981, Bell Helicopter Textron secured a development contract.
The first prototype made its maiden flight on 6 October 1983. It entered service two years later as the OH-58D.
Though designed for multiple roles, the Army initially restricted the OH-58D to field artillery observation due to perceived deficiencies.
The Army also demanded further evaluations. On 1 April 1986, a task force was established at Fort Rucker, Alabama, to address deficiencies in the AHIP.
In 1988, plans to discontinue the OH-58D were halted when Congress allocated $138 million to expand the program.
The AHIP was to cooperate with the Apache, locating targets for the latter to destroy, reminiscent of the OH-58/AH-1 partnership.
Following experiences in the Persian Gulf, the Secretary of the Army directed an upgrade to the aircraft’s armament systems.
This armed version was named the OH-58D Kiowa Warrior. From May 1991, all subsequent OH-58Ds were produced as Kiowa Warriors. In January 1992, Bell obtained its first contract to retrofit all existing OH-58Ds to the Kiowa Warrior configuration.
Bell OH-58 Kiowa Operational History
In May 1969, the Army officially received the first OH-58A Kiowa at a ceremony at Bell Helicopter’s Fort Worth plant.
Major General John Norton of the Army Aviation Materiel Command presided over the ceremony. By 17 August 1969, production OH-58A helicopters were deployed to South Vietnam for the first time.
This deployment included a New Equipment Training Team from the US Army and Bell Helicopters.
Although the Kiowa contract replaced the LOH contract with Hughes, the OH-58A didn’t immediately replace the OH-6A in operations. The Kiowa and the Cayuse operated together until the conflict’s end.
On 27 March 1970, one of the first OH-58A Kiowas was shot down over South Vietnam, marking a notable loss.
Warrant Officer Ralph Quick, Jr., piloted the aircraft, flying Lieutenant Colonel Joseph Benoski, Jr., for artillery spotting. They had just completed assessing battle damage when .51 inch machine gun fire damaged their aircraft.
The crash resulted in the deaths of both crew members. About 45 OH-58As were destroyed during the Vietnam War due to combat and accidents.
One of the last losses involved First Lieutenant Thomas Knuckey and Sergeant Philip Taylor on 27 May 1971.
They were conducting a damage assessment when their aircraft, hit by machine gun fire, exploded. The explosion killed both Knuckey and Taylor.
Operation Prime Chance
In early 1988, it was resolved to replace SEABAT teams of Task Force 160th with armed OH-58D helicopters for Operation Prime Chance.
This operation was concerned with the escort of oil tankers during the Iran–Iraq War. By 24 February 1988, two AHIP helicopters had arrived at the Mobile Sea Base Wimbrown VII. Subsequently, the existing SEABAT team returned to the United States.
Over the following months, duties were shared between AHIP helicopters and the SEABAT team on the Hercules, but coordination was challenging.
Despite multiple requests, a SEABAT team on the Hercules wasn’t replaced by an AHIP detachment until June 1988. OH-58D crews received specialized training from the Navy, preparing for the operation’s unique demands.
In November 1988, the presence of OH-58D helicopters supporting Task Force 118 diminished, but they continued operations from various naval assets.
Their missions largely included nocturnal reconnaissance flights, rotating between sea and land bases due to varying operational requirements.
On 18 September 1989, an OH-58D crashed during a nocturnal exercise but resulted in no casualties. By the time Mobile Sea Base Hercules was decommissioned in September 1989, most OH-58D helicopters had returned to the continental United States.
Operation Desert Storm
During Operation Desert Storm, 115 OH-58D helicopters played a crucial role in diverse combat missions, supporting the success of ground forces.
Throughout Operation Desert Shield and Desert Storm, Kiowas totaled almost 9,000 flight hours, maintaining a 92 percent full mission capable rate.
Impressively, the Kiowa Warrior recorded the lowest maintenance to flight hours ratio among all combat helicopters in the conflict.
RAID The War on Drugs
In 1989, Congress required the Army National Guard to assist in the War on Drugs, aiding various law enforcement agencies with special entitlements. Consequently, the Army National Guard Bureau established the Reconnaissance and Aerial Interdiction Detachments (RAID) in 1992.
This group, spread across 31 states, operated 76 specially modified OH-58A helicopters, focusing on reconnaissance and interdiction roles against illegal drugs.
By 1994, 24 states had executed over 1,200 aerial counterdrug missions, often conducting them at night. Later, the program expanded to 32 states, deploying 116 aircraft, including some for training in Marana, Arizona.
The RAID program now also tackles terrorism and supports U.S. Border Patrol for homeland defense. Unique to the Department of Defense, the National Guard RAID units operate solely within the United States’ borders.
Operation Just Cause
In 1989, during Operation Just Cause, an OH-58 and an AH-1 composed a team within the Aviation Task Force, securing Fort Amador in Panama.
The OH-58, fired upon by Panama Defense Force soldiers, crashed in the Bay of Panama. The pilot was saved, but the co-pilot perished.
In 1994, CWOs David Hilemon and Bobby Hall flew from Camp Page, South Korea, for a routine mission along the Demilitarized Zone (DMZ).
Intending to reach Checkpoint 84, the OH-58C Kiowa inadvertently entered North Korean airspace due to navigation errors in the rugged, snowy terrain.
North Korean troops shot down the helicopter, killing CWO Hilemon. CWO Hall, taken captive, was accused of spying by North Korea.
After tense negotiations, Hilemon’s body was returned, but Hall remained captive for 13 days before being released uninjured on December 30.
Iraq and Afghanistan
During Operation Iraqi Freedom and Operation Enduring Freedom, the U.S. Army used the OH-58D extensively.
In these operations, over 35 airframes were lost to combat and accidents, causing the deaths of 35 pilots. Despite their small size, these helicopters reportedly saved lives by rescuing the wounded.
The helicopters had intensive usage, flying 72 hours per month in Iraq and 80 in Afghanistan. In April 2013, Bell reported that the OH-58D had accumulated 820,000 combat hours with a 90% mission capable rate.
Bell OH-58 Kiowa Replacement and Retirement
The U.S. Army’s initial attempt to replace the OH-58 was with the RAH-66 Comanche, but it was canceled in 2004.
Later, losses led to the Armed Reconnaissance Helicopter program and the Bell ARH-70, canceled in 2008 due to overruns.
The third replacement effort was the Armed Aerial Scout program. The retirement of OH-58F extended from 2025 to 2036 due to fiscal restraints and program uncertainties.
The Kiowa’s role was often supplemented by unmanned aerial vehicles for safer reconnaissance missions.
In 2011, plans emerged to replace the Kiowa by the light version of the Future Vertical Lift aircraft in the 2030s.
In December 2013, the Army had 338 Kiowas in active-duty force and 30 in the Army National Guard. Retirement considerations of the Kiowa were part of a broader restructuring aimed at cutting costs and reducing helicopter variety.
National Guard and Army Reserve
Analyses showed that operating the Kiowa alongside RQ-7 Shadow UAVs was the most affordable and capable solution.
Meanwhile, proposals suggested transferring all National Guard and Army Reserve AH-64s to active Army for scout roles, leading to divesting the OH-58.
The Apache, compared to Kiowa, has a 50 percent higher operation and maintenance cost. Studies indicated that replacing Kiowas with Apaches would have increased total operating costs by $4 billion in Iraq and Afghanistan.
However, it would have also saved $1 billion per year in operating and sustainment costs. The main goal was to retire older helicopters, maintain the most capable ones, and achieve savings.
Retiring the Kiowa would finance upgrades to the Apache.
Excess Defense Article
By 2014, 26 out of 335 OH-58Ds were placed in non-flyable storage, anticipating divestment. Media predicted that the high operating cost of OH-58s would make them more appealing to foreign militaries than civil operators.
By 2015, the Army had divested 33 OH-58Ds, and by January 2016, all but two OH-58D squadrons. The last Kiowa Warrior performed their last live fire maneuver before retirement in January 2017.
Ex-U.S. Army OH-58Ds became available through Excess Defense Article and foreign military sales programs.
In 2016, Croatia and Tunisia became the first to request these helicopters. Croatia received the first batch of 5 OH-58Ds in 2016, and Greece acquired 70 OH-58Ds in early 2018 through an FMS arrangement.
In March 2020, the U.S. Army selected the Bell 360 Invictus and Sikorsky Raider X under the Future Attack Reconnaissance Aircraft (FARA) program to replace the OH-58.
Finally, on 9 July 2020, the U.S. Army retired its last OH-58Cs from active service at Fort Polk.