Bell OH-58 Kiowa
|An OH-58D Kiowa Warrior taking off from Forward Operation Base MacKenzie during the Iraq War in October 2004.|
|Role||Observation and reconnaissance helicopter|
|National origin||United States|
|First flight||Bell 206A: 10 January 1966 |
OH-58D: 6 October 1983
OH-58F: 26 April 2013
|Primary users||United States Army (historical)|
Republic of China Army
Royal Saudi Land Forces
Croatian Air Force
|Number built||2,200|
|Developed from||Bell 206|
The Bell OH-58 Kiowa is a family of single-engine single-rotor military helicopters used for observation, utility, and direct fire support. It was produced by the American manufacturer Bell Helicopter and is closely related to the Model 206A JetRanger civilian helicopter.
The OH-58 was originally developed during the early 1960s as the D-250 for the Light Observation Helicopter (LOH). While the rival Hughes OH-6 Cayuse was picked over Bell's submission in May 1965, the company refined its design to create the Model 206A, a variant of which it successfully submitted to the reopened LOH competition two years later. The initial model, designated by the service as the OH-58A, was introduced in May 1969. Successive models would follow, often with uprated engines, enhanced protection systems, and other improvements, cumulating in the OH-58F. Additional improvements, such as the OH-58X, were proposed but ultimately not pursued.
During the 1970s, the US Army became interested in pursuing an advanced scout helicopter, for which the OH-58 would be further developed, evaluated, and ultimately procured as the OH-58D Kiowa Warrior. The OH-58D is equipped to perform armed reconnaissance missions and to provide fire support to friendly ground forces; it is equipped with a distinctive Mast Mounted Sight (MMS) containing various sensors for target acquisition and laser designation. Another visible feature present on most OH-58s are knife-like extensions above and below the cockpit that form part of the passive wire strike protection system. While early-build OH-58s were equipped with a two-bladed main rotor, from the OH-58D onwards, a four-bladed counterpart was used instead.
The OH-58 was primarily produced for the United States Army, only two months after the type's entry to service, it was first deployed into the Vietnam War. The US Army would make extensive use of various OH-58 models across numerous warzones over the decades, seeing active combat during the Gulf War, the Invasion of Panama, and the War in Afghanistan amongst others. During 2017, the US Army opted to withdraw its remaining OH-58s and replace them with newer rotorcraft, such as the Boeing AH-64 Apache and Eurocopter UH-72 Lakota, as well as increasing use of unmanned aerial vehicles (UAVs). Furthermore, the OH-58 has been exported to Austria, Canada, Croatia, the Dominican Republic, Taiwan, Saudi Arabia, and Greece. It has also been produced under license in Australia.
Light Observation Helicopter (LOH)
On 14 October 1960, the United States Navy approached 25 helicopter manufacturers to request on behalf of the Army the submission of proposals for a Light Observation Helicopter (LOH). Bell Helicopter was one of the manufacturers approached, and chose to enter the competition along with 12 other manufacturers, including Hiller Aircraft and Hughes Tool Co., Aircraft Division. Bell's design was internally referred to as the D-250, and would be officially designated as the YHO-4. On 19 May 1961, Bell and Hiller were announced as winners of the design competition.
Bell developed the D-250 design into the Model 206, while the HO-4 designation was changed to YOH-4A in 1962, and produced five prototype aircraft for the Army's test and evaluation phase. On 8 December 1962, the first prototype performed its maiden flight. The YOH-4A was also called the Ugly Duckling in comparison to other contending aircraft. After a flyoff of the Bell, Hughes and Fairchild-Hiller prototypes, the Hughes OH-6 Cayuse was selected in May 1965.
When the YOH-4A was rejected by the Army, Bell went about solving the problem of marketing the aircraft. In addition to the image problem, the helicopter lacked cargo space and only provided cramped quarters for the planned three passengers in the back. The solution was a fuselage redesigned to be more sleek and aesthetic, adding 16 cubic feet (0.45 cubic metres) of cargo space in the process. The redesigned aircraft was designated as the Model 206A, and Bell President Edwin J. Ducayet named it the JetRanger denoting an evolution from the popular Model 47J Ranger.
In 1967, the Army reopened the LOH competition for bids because Hughes Tool Co. Aircraft Division could not meet the contractual production demands. Bell resubmitted for the program using the Bell 206A. Fairchild-Hiller failed to resubmit their bid with the YOH-5A, which they had successfully marketed as the FH-1100. In the end, Bell underbid Hughes to win the contract and the Bell 206A was designated as the OH-58A. Following the U.S. Army's naming convention for helicopters, the OH-58A was named Kiowa in honor of the Native American tribe.
Advanced Scout Helicopter
In the 1970s, the U.S. Army began evaluating the need to improve the capabilities of their scout aircraft. Anticipating the AH-64A's replacement of the venerable AH-1, the Army began shopping the idea of an Aerial Scout Program to stimulate the development of advanced technological capabilities for night vision and precision navigation equipment. The stated goals of the program included prototypes that would:
"...possess an extended target acquisition range capability by means of a long-range stabilized optical subsystem for the observer, improved position location through use of a computerized navigation system, improved survivability by reducing aural, visual, radar, and infrared signatures, and an improved flight performance capability derived from a larger engine to provide compatibility with attack helicopters".
During March 1974, the Army created a special task force at Fort Knox to develop the system requirements; by the following year, the task force had devised the requirements for an Advanced Scout Helicopter (ASH) program. The requirements were formulated around an rotorcraft capable of performing in day, night, and adverse weather, and compatible with all advanced weapons systems planned for development and fielding into the 1980s. The program was approved by the System Acquisition Review Council and the Army prepared for competitive development to begin the next year. However, as the Army tried to get the program off the ground, Congress declined to provide funding in the fiscal year 1977 budget and the ASH Project Manager's Office (PM-ASH) was closed on 30 September 1976.
While no development occurred for some years, the program survived as a requirement without funding. On 30 November 1979, the decision was made to defer development of an advanced scout helicopter in favor of modifying existing airframes in inventory as a near term scout helicopter (NTSH) option. The development of a mast-mounted sight would be the primary focus to improve the ability to perform reconnaissance, surveillance, and target acquisition missions while remaining hidden behind trees and terrain. Both the UH-1 and the OH-58 were evaluated as NTSH candidates, but the UH-1 was dropped from consideration due to its larger size and ease of detection. The OH-58, on the other hand demonstrated a dramatic reduction in detectability with a Mast-Mounted Sight (MMS).
On 10 July 1980, the Army decided that the NTSH would be a competitive modification program based on developments in the commercial helicopter sector, particularly Hughes Helicopters' Hughes 500D, which had made major improvements over the OH-6.
Army Helicopter Improvement Program (AHIP)
The Army's decision to acquire the NTSH resulted in the "Army Helicopter Improvement Program (AHIP)". Both Bell Helicopter and Hughes Helicopters redesigned their scout aircraft to compete for the contract. Bell offered a more robust version of the OH-58 in their Model 406, and Hughes offered an upgraded version of the OH-6. On 21 September 1981, Bell Helicopter Textron was awarded a development contract. On 6 October 1983, the first prototype performed its maiden flight, and the aircraft entered service two years later as the OH-58D.
Initially intended for attack, cavalry, and artillery roles, the Army only approved a low initial production level and confined the OH-58D's role to field artillery observation. The Army also directed that a follow-on test be conducted to further evaluate it due to perceived deficiencies. On 1 April 1986, the Army formed a task force at Fort Rucker, Alabama, to remedy deficiencies in the AHIP. During 1988, the Army had planned to discontinue the OH-58D and focus on the LHX; however, Congress approved $138 million to expand the program, calling for the AHIP to operate with the Apache as a hunter/killer team; the AHIP would locate targets and the Apache would destroy them in a throwback to the traditional OH-58/AH-1 relationship.
The Secretary of the Army directed instead that the aircraft's armament systems be upgraded, based on experience with Task Force 118's performance operating armed OH-58Ds in the Persian Gulf in support of Operation Prime Chance, and that the type be used primarily for scouting and armed reconnaissance. The armed aircraft would be known as the OH-58D Kiowa Warrior, denoting its new armed configuration. Beginning with the 202nd aircraft (s/n 89-0112) in May 1991, all remaining OH-58Ds were produced in the Kiowa Warrior configuration. During January 1992, Bell received its first retrofit contract to convert all remaining OH-58Ds to the Kiowa Warrior configuration.
The Bell OH-58 Kiowa is a family of single-engine single-rotor military helicopters principally used for observation, utility, and direct fire support. The primary role of the original OH-58A was identify targets for other platforms, such as the Bell AH-1 Cobra attack helicopter and ground artillery; it lacked any armaments and weighed 1,451kg (3,200lb) when fully loaded, being able to carry a small amount of cargo or two passengers. While initial examples were reliant on the eyes of the crew to conduct observations, later models were furnished with sophisticated sensors to precisely determine a target's location. Payload capacity was also increased considerably on later-build rotorcraft, the OH-58D Kiowa was designed to carry a maximum load of 2,495kg, 72% more capacity than the original version.
Early Kiowas were fitted with a flexible twin-bladed main rotor; starting with the OH-58D, a four-bladed rigid main rotor was used. This was entirely composed of composite materials, the OH-58D was the first US Army rotorcraft to incorporate an all-composite main rotor hub. Later models were outfitted as light gunships, being equipped with various armaments, such as Stinger air-to-air missiles, a .50-calibre machine gun, podded 70mm Hydra rockets and AGM-114 Hellfire air to ground missiles. Other areas of improvement were the avionics and the cockpit; new navigation and communication systems were installed along with new and larger flight instrumentation, while all light sources were redesigned for compatibility with Night Vision Goggles (NVG). Later versions were outfitted with a glass cockpit, which retained conventional instrumentation as a fallback measure.
The OH-58D introduced perhaps the most distinctive feature of the Kiowa family — the Mast Mounted Sight (MMS), which resembles a beach ball perched above the rotor system. The MMS by Ball Aerospace & Technologies has a gyro-stabilized platform containing a television system (TVS), a thermal imaging system (TIS), and a laser range finder/designator (LRF/D). These features gave the OH-58D the additional mission capability of target acquisition and laser designation in day or night, limited-visibility and adverse weather. In combination with the 1553 databus, the OH-58D being first US Army helicopter to be fielded with such equipment, target data from the sensors could be directly passed to precision-guided weapons.
The MMS was developed by the McDonnell Douglas Corp. in Huntington Beach, CA. Production took place primarily at facilities in Monrovia, CA. As a result of a merger with Boeing, and a later sale of the business unit, the program is currently owned and managed by DRS Technologies, with engineering support based in Cypress, CA, and production support taking place in Melbourne, FL. On the OH-58F, the MMS was removed, its functions having been replaced by the AAS-53 Common Sensor Payload, which is mounted on the chin.
One distinctive feature of operational OH-58s are the knife-like extensions above and below the cockpit which are part of the passive wire strike protection system; it protects 90% of the frontal area of the helicopter from wire strikes that can be encountered at low altitudes by directing wires to the upper or lower blades before they can entangle the rotor blade or landing skids. The OH-58 was the first helicopter to test this system, after which the system was adopted by the US Army for the OH-58 and most of their other helicopters. Various other defensive and survivability measures were incorporated, such as ballistic floor armor, a missile warning system, crashworthy seats, and infrared suppression systems for the engine exhaust.
During May 1969, the first OH-58A Kiowa was officially received at a ceremony held at Bell Helicopter's Fort Worth plant, officiated by Major General John Norton, commanding general of the Army Aviation Materiel Command (AMCOM). Two months later, on 17 August 1969, production OH-58A helicopters arrived in South Vietnam for the first time; their deployment was accompanied by a New Equipment Training Team (NETT) comprising personnel from both the US Army and Bell Helicopters. Although the Kiowa production contract had replaced the LOH contract with Hughes, the OH-58A did not automatically replace the OH-6A in operations; subsequently, the Kiowa and the Cayuse would continue operating in the same theater until the end of the conflict.
On 27 March 1970, an OH-58A Kiowa (s/n 68-16785) was shot down over South Vietnam, one of the first OH-58A losses of the war. The pilot, Warrant Officer Ralph Quick, Jr., was flying Lieutenant Colonel Joseph Benoski, Jr. as an artillery spotter. After completing a battle damage assessment for a previous fire mission, the aircraft was damaged by .51 inch (13 mm) machine gun fire and crashed, killing both crew members. Approximately 45 OH-58A helicopters were destroyed during the Vietnam War due to combat losses and accidents. One of the last combat losses in the theatre was of an OH-58A (s/n 68-16888) from A Troop, 3-17th Cavalry, flown by First Lieutenant Thomas Knuckey. On 27 May 1971, Lieutenant Knuckey was also flying a battle damage assessment mission when his aircraft came under machine gun fire and exploded. Knuckey and his observer, Sergeant Philip Taylor, both died in the explosion.
Operation Prime Chance
During early 1988, it was decided that armed OH-58D (AHIP) helicopters from the 118th Aviation Task Force would be phased in to replace the SEABAT (AH-6/MH-6) teams of Task Force 160th to carry out Operation Prime Chance, the escort of oil tankers during the Iran–Iraq War. On 24 February 1988, two AHIP helicopters reported to the Mobile Sea Base Wimbrown VII, and the helicopter team ("SEABAT" team after their callsign) stationed on the barge returned to the United States. For the next few months, the AHIP helicopters on the Wimbrown VII shared patrol duties with the SEABAT team on the Hercules. Coordination proved difficult, despite frequent requests from TF-160, the SEABAT team on the Hercules was not replaced by an AHIP detachment until June 1988. The OH-58D helicopter crews involved in the operation received deck landing and underwater survival training from the Navy.
In November 1988, the number of OH-58D helicopters that supported Task Force 118 was reduced. However, the rotorcraft continued to operate from the Navy's Mobile Sea Base Hercules, the frigate Underwood, and the destroyer Conolly. OH-58D operations primarily entailed reconnaissance flights at night, and depending on maintenance requirements and ship scheduling, Army helicopters usually rotated from the mobile sea base and other combatant ships to a land base every seven to fourteen days. On 18 September 1989, an OH-58D crashed during night gunnery practice and sank, but with no loss of personnel. When the Mobile Sea Base Hercules was deactivated in September 1989, all but five OH-58D helicopters redeployed to the continental United States.
During Operation Desert Storm, 115 deployed OH-58D helicopters participated in a wide variety of critical combat missions and were vital to the success of the ground forces mission. During Desert Shield and Desert Storm, the Kiowas collectively flew nearly 9,000 hours with a 92 percent fully mission capable rate. The Kiowa Warrior had the lowest ratio of maintenance hours to flight hours of any combat helicopter in the war.
In 1989, Congress mandated that the Army National Guard would take part in the country's War on Drugs, enabling them to aid federal, state and local law enforcement agencies with "special congressional entitlements". In response, the Army National Guard Bureau created the Reconnaissance and Aerial Interdiction Detachments (RAID) in 1992, consisting of aviation units in 31 states with 76 specially modified OH-58A helicopters to assume the reconnaissance/interdiction role in the fight against illegal drugs. During 1994, 24 states conducted more than 1,200 aerial counterdrug reconnaissance and interdiction missions, conducting many of these missions at night. Eventually, the program was expanded to cover 32 states and consisting of 116 aircraft, including dedicated training aircraft at the Western Army Aviation Training Site (WAATS) in Marana, Arizona.
The RAID program's mission has now been expanded to include the war against terrorism and supporting U.S. Border Patrol activities in support of homeland defense. The National Guard RAID units' Area of Operation (AO) is the only one in the Department of Defense that is wholly contained within the borders of the United States.
Operation Just Cause and action in the 1990s
During Operation Just Cause in 1989, a team consisting of an OH-58 and an AH-1 were part of the Aviation Task Force during the securing of Fort Amador in Panama. The OH-58 was fired upon by Panama Defense Force soldiers and crashed 100 yards (90 m) away, in the Bay of Panama. The pilot was rescued, but the co-pilot died.
On 17 December 1994, Army Chief Warrant Officers (CWO) David Hilemon and Bobby Hall left Camp Page, South Korea on a routine training mission along the Demilitarized Zone (DMZ). Their flight was intended to be to a point known as Checkpoint 84, south of the DMZ "no-fly zone", but the OH-58C Kiowa strayed nearly four miles (6 km) into the Kangwon Province, inside North Korean airspace, due to errors in navigating the snow-covered, rugged terrain. The helicopter was shot down by North Korean troops and CWO Hilemon was killed. CWO Hall was held captive and the North Korean government insisted that the crew had been spying. Five days of negotiations resulted in the North Koreans turning over Hilemon's body to U.S. authorities. The negotiations failed to secure Hall's immediate release. After 13 days in captivity, Hall was freed on 30 December, uninjured.
Afghanistan and Iraq
The U.S. Army employed the OH-58D during Operation Iraqi Freedom in Iraq and Operation Enduring Freedom in Afghanistan. Between a combination of combat and accidents, over 35 airframes have been lost, resulting in the deaths of 35 pilots. Their presence was also anecdotally credited with saving lives, having been used to rescue wounded despite their small size. In Iraq, OH-58Ds reportedly flew 72 hours per month, while in Afghanistan, the type flew 80 hours per month. During April 2013, Bell stated that the OH-58 collectively accumulated 820,000 combat hours, and had achieved a 90% mission capable rate.
The U.S. Army's first attempt to replace the OH-58 was the RAH-66 Comanche of the Light Helicopter Experimental program, which was canceled in 2004. Airframe age and losses led to the Armed Reconnaissance Helicopter program and the Bell ARH-70, which was canceled in 2008 due to cost overruns. The third replacement effort was the Armed Aerial Scout program. Due to uncertainty in the AAS program and fiscal restraints, the OH-58F's planned retirement was extended from 2025 to 2036. The Kiowa's scout role was supplemented by tactical unmanned aerial vehicles, the two platforms often acting in conjunction to provide reconnaissance to expose crews to less risk. The OH-58F had the ability to control UAVs directly to safely perform scout missions. In 2011, the Kiowa was scheduled to be replaced by the light version of the Future Vertical Lift aircraft in the 2030s.
In December 2013, the U.S. Army had 338 Kiowas in its active-duty force and 30 in the Army National Guard. The Army considered retiring the Kiowa as part of a wider restructuring to cut costs and reduce the variety of helicopters operated. The Analysis of Alternatives for the AAS program found that operating the Kiowa alongside RQ-7 Shadow UAVs was the most affordable and capable solution, while the AH-64E Apache Guardian was the most capable immediate solution. One proposal was to transfer all Army National Guard and Army Reserve AH-64s to the active Army for use as scouts to divest the OH-58. The Apache costs 50 percent more than the Kiowa to operate and maintain; studies note that had it been used in place of the Kiowa in Iraq and Afghanistan, total operating costs would have risen by $4 billion, but also saved $1 billion per year in operating and sustainment costs. UH-60 Black Hawks would transfer from the active Army to reserve and Guard units. The aim was to retire older helicopters and retain those with the best capabilities to save money. Retiring the Kiowa would fund Apache upgrades.
The Army placed 26 out of 335 OH-58Ds in non-flyable storage during 2014. In anticipation of divestment, the Army looked to see if other military branches, government agencies, and foreign customers had interest in buying the type. The Kiowas were considered to be well priced for foreign countries with limited resources; Bell had not yet agreed to support them if sold overseas. Media expected OH-58s to go to foreign militaries rather than civil operators due to high operating cost. By 2015, the Army had divested 33 OH-58Ds. By January 2016, the Army had divested all but two OH-58D squadrons. In June 2016, members of 1st Squadron, 17th Cavalry Regiment, 82nd Combat Aviation Brigade, arrived in South Korea as part of the Kiowa's last deployment in U.S. Army service. In January 2017, the last Kiowa Warrior performed their last live fire maneuver before retirement.
Ex-U.S. Army OH-58Ds were made available through Excess Defense Article and foreign military sales (FMS) programs. In November 2014, Croatia sent a letter of intent for the acquisition of 16 OH-58Ds. In 2016, Croatia and Tunisia became the first nations to request the helicopters, ordering 16 and 24, respectively. Croatia received the first batch of 5 OH-58Ds at the Zadar-Zemunik air base on 30 June 2016. In early 2018, Greece was granted 70 OH-58Ds via an FMS arrangement, the type has been initially stationed at Hellenic Army Aviation air base at Stefanovikio.
In March 2020, the U.S. Army selected the Bell 360 Invictus and Sikorsky Raider X as part of the Future Attack Reconnaissance Aircraft (FARA) program to fill the capability gap left by the retirement of the OH-58. On 9 July 2020, the US Army retired its last OH-58Cs from active service at Fort Polk.
The OH-58A Kiowa is a four-place observation helicopter. It has two-place pilot seating, although the controls in the left seat are designed to be removed to carry a passenger up front. During its Vietnam development, it was fitted with the M134 Minigun, a 7.62 mm electrically operated machine gun.
The Australian Army leased eight OH-58As in 1971 in Vietnam for eight months. A total of 74 OH-58As were delivered to the Canadian Armed Forces as COH-58A and later redesignated CH-136 Kiowa. As many as 12 surplus Kiowas were sold to the Dominican Republic Air Force, and others sold privately in Australia.
In 1978, OH-58As began to be converted to the same engine and dynamic components as the OH-58C. In 1992, 76 OH-58A were modified with another engine upgrade, a thermal imaging system, a communications package for law enforcement, enhanced navigational equipment and high skid gear as part of the Army National Guard's (ARNG) Counter-Drug RAID program. The U.S. Army retired its last OH-58A in November 2017.
The OH-58B was an export version for the Austrian Air Force. The Australian Government also procured the OH-58A for the Australian Army and Royal Australian Navy as the CAC CA-32. Licensed produced in Australia by Commonwealth Aircraft Corporation, the CA-32 was the equivalent of the 206B-1 (upgraded engine and longer rotor blades). The first twelve of 56 were built in the U.S. then partially disassembled and shipped to Australia, where they were reassembled. Helicopters in the naval fleet were retired in 2000.
Equipped with a more robust engine, the OH-58C was supposed to solve issues regarding the Kiowa's power. In addition to the upgraded engine, it had unique IR suppression systems mounted on its exhaust. Early OH-58Cs had flat-panel windscreens as an attempt to reduce glint from the sun, which could reveal its location to enemies. The windscreens had a negative effect of limiting the crew's forward view, a previous strength of the original design.
The aircraft was also equipped with a larger instrument panel, roughly a third bigger than the OH-58A panel, which held larger flight instruments. The panel was also equipped with Night Vision Goggle (NVG) compatible cockpit lighting. The OH-58C were also the first U.S. Army scout helicopter to be equipped with the AN/APR-39 radar detector, which alerted the crew to active anti-aircraft radar systems nearby. Some OH-58Cs were armed with two AIM-92 Stingers and are sometimes referred to as OH-58C/S, the "S" referring to the Stinger addition. Called Air-To-Air Stinger (ATAS), the weapon system was intended to provide an air defense capability.
The OH-58C was the final variant of the Kiowa in active service with the US Army, its final use with the service being as a training aircraft. On 9 July 2020, the US Army retired the last OH-58Cs from service.
The OH-58D (Bell Model 406) was the result of the Army Helicopter Improvement Program (AHIP). An upgraded transmission and engine gave extra power, needed for nap-of-the-earth flight profiles, and a four-bladed main rotor made it quieter than the two-bladed OH-58C. The OH-58D introduced the distinctive Mast-Mounted Sight (MMS) above the main rotor, and a mixed glass cockpit with traditional instruments as "standby" for emergencies.
The Bell 406CS "Combat Scout" was based on the OH-58D (sometimes referred to as the MH-58D). Fifteen aircraft were sold to Saudi Arabia. A roof-mounted Saab HeliTOW sight system was opted for in place of the MMS. The 406CS also had detachable weapon hardpoints on each side.
The AH-58D was an OH-58D version operated by Task Force 118 (4th Squadron, 17th Cavalry) and modified with armament in support of Operation Prime Chance. The weapons and fire control systems would become the basis for the Kiowa Warrior. AH-58D is not an official DOD aircraft designation, but is used by the Army in reference to these aircraft.
The Kiowa Warrior, sometimes referred to by its acronym KW, is the armed version of the OH-58D. A key difference between the Kiowa Warrior and original AHIP aircraft is a universal weapons pylon found mounted on both sides of the fuselage, capable of carrying combinations of AGM-114 Hellfire missiles, air-to-air Stinger (ATAS) missiles, 7-shot 2.75 inches (70 mm) Hydra-70 rocket pods, and an M296 0.50 in (12.7 mm) caliber machine gun. The performance standard of aerial gunnery from an OH-58D is to achieve at least one hit out of 70 shots fired at a wheeled vehicle 800 to 1,200 m (2,600 to 3,900 ft) away. The Kiowa Warrior also includes improvements in available power, navigation, communication, survivability, and deployability.
The OH-58F is an OH-58D upgrade. The Cockpit and Sensor Upgrade Program (CASUP) adds a nose-mounted targeting and surveillance system alongside the MMS. The AAS-53 Common Sensor Payload has an infrared camera, color Electro-Optical camera, and image intensifier; via weight and drag reductions, flight performance increased by 1–2%. Cockpit upgrades include the Control and Display Subsystem version 5, with more storage and processing power, three color multi-function displays, and dual-independent advanced moving maps. It has Level 2 Manned-Unmanned (L2MUM) teaming, the Force Battle Command Brigade and Below (FBCB2) display screen, and can be updated to Blue Force Tracker 2. Survivability enhancements include ballistic floor armor and the Common Missile Warning System. It has greater situational awareness, digital inter-cockpit communications, HELLFIRE future upgrades, redesigned wiring harness, Health and Usage Monitoring (HUMS), and enhanced weapons functionality via 1760 digital interface. The OH-58F is powered by a Rolls-Royce 250-C30R3 engine rated at 650 shp (480 kW); it has a dual-channel, full-authority digital engine-controller that operates at required power levels in all environments. Rolls-Royce proposed engine tweaks to raise output by 12%.
In October 2012, the first OH-58F was finished. Unlike most military projects, the Army designed and built the new variant itself, which lowered development costs. It weighed 3,590 lb (1,630 kg), 53 lb (24 kg) below the target weight and about 200 lb (91 kg) lighter than the OH-58D. The weight savings are attributed to more efficient wiring and a lighter sensor. The first production aircraft started being built in January 2013 and was handed over to the Army by year end. Low rate production was to start in March 2015, with the first operational squadron being fully equipped by 2016. The Army was to buy 368 OH-58Fs, with older OH-58 variants to be remanufactured. Due to battle damage and combat attrition, total OH-58F numbers would be about 321 aircraft. The OH-58F's first flight occurred on 26 April 2013.
The Army chose to retire the Kiowa and end the CASUP upgrades. CASUP and SLEP upgrades was costed at $3 billion and $7 billion respectively. The OH-58D could do 20 percent of armed aerial scout mission requirements, the OH-58F upgrade raised that to 50 percent. Replacing the Kiowa with Apaches and UAVs in scout roles met 80 percent of requirements. In early 2014, Bell received a stop-work order for the Kiowa CASUP program.
OH-58F Block II
On 14 April 2011, Bell performed the successful first flight of the OH-58F Block II variant. It was Bell's entry in the Armed Aerial Scout (AAS) program. It built on the improvements of the F-model, adding features such as the Honeywell HTS900 turboshaft engine, the transmission and main rotors of the Bell 407, and the tail and tail rotor of the Bell 427. Bell started flight demonstrations in October 2012. Bell hoped for the Army to go with their service life extension models instead of the AAS program. The OH-58F is an "obsolescence upgrade", while the Block II was seen as the performance upgrade. This gave the Army financial flexibility via the option of upgrading the Kiowa to the OH-58F and later continuing to the Block II when there were sufficient funds. In late 2012, the Army recommended that the AAS program proceed. The Army ended the AAS program in late 2013. In light of sequestration budget cuts in 2013, it was decided that the $16 billion cost to buy new armed scout helicopters was too great.
The OH-58X was a modification of the fourth development OH-58D (s/n 69-16322) with partial stealth features and a chin-mounted McDonnell-Douglas Electronics Systems turret as a night piloting system; including a Kodak FLIR system with a 30-degree field of view. Avionics systems were consolidated and moved to the nose, making room for a passenger seat in the rear. No aircraft were produced.
Aircraft on display
- 68-16940 – International Airport in Palm Springs, California. Transformed into a sculpture.
- 69-16112 – Pima Air and Space Museum in Tucson, Arizona
- 69-16123 – Kansas Museum of Military History in Augusta, Kansas
- 69-16153 – MAPS Air Museum in North Canton, Ohio
- 69-16338 – Point Alpha Museum in Hesse, Germany
- 71-20475 – Veterans Memorial Museum, Huntsville, Alabama, United States
- 71-20869 – National Air Force Museum of Canada, Trenton, Ontario, Canada CH-136 
- 71-20920 – Polish Aviation Museum, Kraków, Poland – CH-136
- 72-21256 – The Aviation Museum of Kentucky in Lexington, Kentucky
- Crew: 2 pilots
- Length: 42 ft 2 in (12.85 m)
- Height: 12 ft 10 in (3.93 m)
- Empty weight: 3,829 lb (1,737 kg)
- Gross weight: 5,500 lb (2,495 kg)
- Powerplant: 1 × Rolls-Royce T703-AD-700A turboshaft, 650 hp (485 kW)
- Main rotor diameter: 35 ft 0 in (10.67 m)
- Main rotor area: 962.11 sq ft (89.42 m2)
- Maximum speed: 149 mph (240 km/h, 129 kn)
- Cruise speed: 127 mph (204 km/h, 110 kn)
- Range: 161 mi (556 km, 140 nmi)
- Endurance: Two hours
- Service ceiling: 15,000 ft (4,575 m)
- Hardpoints: Two pylons , with provisions to carry combinations of:
Aircraft of comparable role, configuration, and era
- The last new build aircraft were delivered to the U.S. Army in 1989. The subsequent arming of the AHIP and the System Safety Enhancement Program (SSEP) caused aircraft to be steadily refitted until 1999.
- Donald, David, ed. "Bell Model 206 JetRanger", The Complete Encyclopedia of World Aircraft. Barnes & Nobel Books, 1997. ISBN 0-7607-0592-5.
- Jackson, Paul, Lindsay T. Peacock, Kenneth Munson, and John W. R. Taylor. Jane's All the World's Aircraft, 1996–97. Coulsdon, Surrey, UK: Jane's Information Group, 1996. ISBN 978-0-7106-1377-6.
- Cannon, Chuck (14 July 2020). "Kiowa helicopters make final flight at JRTC & Fort Polk". Vertical Magazine. Archived from the original on 11 November 2020. Retrieved 11 November 2020.
- Remington, Steve. "The Cessna CH-1 Helicopter". CollectAir.com. Archived from the original on 21 June 2009.
- Beechy, Robert (18 November 2005). "U.S Army Aircraft Acquisition Programs". Uncommon Aircraft 2006. Archived from the original on 18 November 2006. Retrieved 19 September 2006.
- See Light Observation Helicopter. The Navy, who was assisting the Army in the selection phase, recommended the Hiller Model 1100, while the Army team preferred the Bell D-250, and then the 1100. The Selection Board selected both aircraft. Afterwards, the acting Army Chief of Staff directed the Selection Board to include the Hughes 369 in the fly-off competition.
- Spangenberg, George A. Judith Spangenberg-Currier (ed.). "George A. Spangenberg Oral History" (PDF). georgespangenberg.com. pp. 187–190. Archived from the original (PDF) on 10 September 2008. Retrieved 29 April 2008.
- Visschedijk, Johan (16 October 2003). "Bell 206 JetRanger". 1000AircraftPhotos.com. Archived from the original on 14 September 2006. Retrieved 19 September 2006.
- Spenser, Jay P. "Bell Helicopter". Whirlybirds, A History of the U.S. Helicopter Pioneers, p. 263. University of Washington Press, 1998. ISBN 0-295-98058-3.
- Aastad, Andy (Winter 2006–2007). "The Introduction to the JetRanger" (PDF). Rotor Magazine. Helicopter Association International. Archived from the original (PDF) on 10 September 2008. Retrieved 29 April 2008.
- Holley and Sloniker, p. 8.
- Trimble, Stephen (13 December 2010). "CUTAWAY: Ultimate Survivor - OH-58 enters fifth decade stronger than ever". flightglobal.com.
- Hirschberg, Michael J. and David K. Daley. "Bell". Archived 5 June 2001 at the Wayback Machine US and Russian Helicopter Development In the 20th Century. American Helicopter Society. 7 July 2000. Accessed on 20 April 2007.
- Holley and Sloniker, p. 90.
- Cocke, Karl E. (1972). "V Force Development". Department of the Army Historical Summary. United States Army Center of Military History. Archived from the original on 2 June 2013. Retrieved 17 January 2014.
- Cocke, Karl E. (1978). "XI Research, Development and Acquisition". Department of the Army Historical Summary, 1974. United States Army Center of Military History. Archived from the original on 14 December 2007. Retrieved 14 April 2007.
- Cocke, Karl E. (1978). "X Research, Development and Acquisition". Department of the Army Historical Summary, 1975. United States Army Center of Military History. Archived from the original on 14 December 2007.
- Cocke, Karl E. (1977). "Research, Development and Acquisition". Department of the Army Historical Summary, 1976. United States Army Center of Military History. Archived from the original on 14 May 2008. Retrieved 14 April 2007.
- "11. Research Development and Acquisition". Department of the Army Historical Summary, 1980. United States Army Center of Military History. 1983. Archived from the original on 14 December 2007. Retrieved 14 April 2007.
- "Historic U.S. Army Helicopters". Archived from the original on 24 February 2007. Retrieved 14 April 2007.
- Fairweather Jr., Robert S.; Fossum, Grant (July–August 1982). "The AHIP: Field Artillery Aerial Observer Platform of the Future" (PDF). Field Artillery Magazine. Archived from the original (PDF) on 23 November 2016.
- "Research Development and Acquisition". Department of the Army Historical Summary, 1981. United States Army Center of Military History. 1988. Archived from the original on 14 December 2007. Retrieved 14 April 2007.
- Gough, Terrence J. (1995). "Modernizing and Equipping the Army". Department of the Army Historical Summary, 1986. United States Army Center of Military History. Archived from the original on 21 September 2010. Retrieved 30 June 2010.
- Webb, William Joe (1993). "Modernizing and Equipping the Army". Department of the Army Historical Summary, 1988. United States Army Center of Military History. Archived from the original on 21 September 2010. Retrieved 30 June 2010.
- Demma, Vincent H. (1998). "11. Modernization: Research, Development and Acquisition". Department of the Army Historical Summary, 1989. United States Army Center of Military History. Archived from the original on 21 September 2010. Retrieved 30 June 2010.
- "Fiscal Year 1986: Chapter 4". Department of the Army Historical Summary. p. 43. Archived from the original on 22 January 2009. Retrieved 17 February 2017.
- "DRS Technologies, Inc. – Mast-Mounted Sight (MMS)". DRS Technologies. Archived from the original on 8 November 2012. Retrieved 11 February 2013.
- Magellan Aerospace. "WSPS". magellan.aero. Archived from the original on 1 December 2018. Retrieved 1 December 2018.
- "Army Aviation Hall of Fame: Lieutenant General John Norton". Army Aviation Association of America. Archived from the original on 14 August 2009. Retrieved 22 October 2008.
- "Historic U.S. Army Helicopters". 5 October 2005. Archived from the original on 12 February 2003.
- "Bell Helicopter News information". Vietnam Helicopter Pilot's Association. Archived from the original on 8 December 2008. Retrieved 22 October 2008.
- Roush, Gary (29 October 2008). "Helicopter Losses During the Vietnam War" (PDF). VHPA.org. Archived from the original (PDF) on 29 October 2008. Retrieved 4 January 2009.
- "Kiowa crewmember line of duty deaths". armyaircrews.com. 31 December 2008. Archived from the original on 31 December 2008. Retrieved 4 January 2009.
- "Operations EARNEST WILL and PRIME CHANCE". Night Stalker History. Archived from the original on 15 June 2002. Retrieved 25 March 2007.
- Demma, Vincent H. (1998). "6. Operations". Department of the Army Historical Summary, 1989. United States Army Center of Military History. CMH Pub 101-21. Archived from the original on 14 December 2007. Retrieved 25 March 2007.
- "The End of an Era: OH-58 Kiowa". www.dvidshub.net.
- Kaplan, L. Martin (2000). "5. Reserve Forces". Department of the Army Historical Summary, 1994. United States Army Center of Military History. CMH Pub 101-25. Archived from the original on 21 September 2010. Retrieved 30 June 2010.
- Nelms, Doug (1 November 2002). "Homeland Defense: Fighting Homeland Wars". Rotor & Wing via aviationtoday.com. Archived from the original on 28 February 2004. Retrieved 2 October 2016.
- Operation Just Cause: The Incursion into Panama. United States Army Center of Military History. CMH Pub No. 70-85-1. Archived from the original on 13 December 2007. Retrieved 1 September 2006.
- Office of the Assistant Secretary of Defense (Public Affairs). (19 December 1994). "OH-58C Helicopter Down in North Korea". United States Department of Defense. Archived from the original on 15 May 2007. Retrieved 30 December 2007.
- Miles, Donna (4–5 February 1995). "Drama Along the DMZ". Soldiers. Archived from the original on 7 February 2006. Retrieved 3 November 2006.
- "OH-58D Kiowa Warrior Reconnaissance / Attack Helicopter, USA". SPG Media Limited. 27 November 2007. Archived from the original on 4 July 2008. Retrieved 4 August 2008.
- Sayah, Reza; Starr, Barbara; McIntyre, Jamie (25 September 2008). "U.S., Pakistan exchange shots at volatile border". CNN.com. Archived from the original on 22 January 2009. Retrieved 15 January 2009.
- Hastings, Michael (September 2010). "America's New Cavalry". Men's Journal: 128.
- Thackary, Lorna (18 April 2010). "Injured Red Lodge soldier recounts blast, dramatic rescue in Afghanistan". BillingsGazette.com. Archived from the original on 8 June 2013. Retrieved 31 May 2013.
- "Another Old Warrior Too Good To Replace". Strategypage.com. 14 May 2013. Archived from the original on 16 May 2013.
- "Bell Helicopter Provides OH-58 Kiowa Warrior Program Update". Bell/Textron. 12 April 2013. Archived from the original on 8 December 2013. Retrieved 8 December 2013.
- "U.S. Army officials said to back new scout helicopter". Reuters.com. 30 November 2012. Archived from the original on 24 September 2015.
- "U.S. Army Confirms AAS Will Be New Start Or OH-58 SLEP". Aviationweek.com. 10 May 2013. Archived from the original on 23 October 2013.
- "Superfast Helicopters". Defensemedianetwork.com. 25 October 2011. Archived from the original on 31 March 2013.
- "Army Plans To Scrap Kiowa Helo Fleet". MarineCorpstimes.com. 9 December 2013. Archived from the original on 14 December 2013.
- "Army aviation flying smarter into fiscal squeeze". Army.mil. 14 January 2014. Archived from the original on 24 January 2014.
- "US Army begins grounding Kiowas, seeks buyers". Flightglobal.com. 7 May 2014. Archived from the original on 8 May 2014.
- Host, Pat (April 2015). "Army's aviation restructuring not to affect civil helicopter market". Rotor & Wing. pp. 38–42. Archived from the original on 12 April 2015.
- "Downsized US Army to pass on 533 shunned OH-58, TH-67 helicopters". Archived from the original on 17 July 2015.
- "US Army forging ahead with OH-58D and TH-67 retirements". Flightglobal.com. 14 January 2016. Archived from the original on 15 February 2016.
- Brooks, Drew (12 April 2016). "Army's Kiowa helicopters to fly in last formation". The Fayetteville Observer. Retrieved 2 June 2016.
Nearly three years after defense officials first proposed eliminating the small aircraft from the Army's aviation, all but two squadrons – each flying 30 helicopters – have bid adieu to the Kiowa
- "Final deployment is underway for Army's Kiowa helicopters". Armytimes.com. 26 June 2016.
- "Kiowa Warriors pass torch to Apache attack helicopters in South Korea". Stars and Stripes. 26 January 2017. Archived from the original on 25 May 2017. Retrieved 13 May 2017.
- "KOTROMANOVIĆ PISAO PENTAGONU Hrvatska traži od SAD-a 16 borbenih letjelica". jutarnji.hr. Archived from the original on 3 March 2016. Retrieved 2 October 2016.
- "Croatia, Tunisia First To Receive U.S. Kiowa Warriors". Ainonline.com. 6 June 2016. Archived from the original on 10 June 2016.
- "Tunisia-OH-58D Kiowa Warrior Aircraft Equipment and Support". dsca.mil. 3 May 2016. Archived from the original on 17 June 2016.
- Salinger, Igor (2 August 2016). "First ex-US Army OH-58Ds delivered to Croatia". FlightGlobal. Archived from the original on 2 August 2016.
- Tabak, Igor (2 August 2016). "Croatia receives first OH-58 Kiowa helicopters". IHS Jane's 360. Archived from the original on 2 August 2016.
- Bumgardner, Richard (13 December 2019). "After nearly 50 years as the Army's workhorse, the venerable Kiowa helicopter is taking flight again for Greece". businessinsider.com.
- "Bell, Sikorsky Move On To Next Round of Army's FARA Derby". Aviation International News. 25 March 2020.
- "Lockheed and Bell will compete head-to-head to build US Army's future attack recon aircraft". Defense News. 26 March 2020.
- "History of Bell OH58-A Kiowa Helicopter". 161 Possums formerly 161 Recce Association. Archived from the original on 2 March 2001. Retrieved 8 August 2016.
- "Army A17 & RAN N17 Bell 206B-1/OH-58A & CAC CA-32 Kiowa". Australian & New Zealand Military Aircraft Serials & History. Archived from the original on 19 August 2016. Retrieved 8 August 2016.
- "Bell CH-136 Kiowa". Air Force Public Affairs, Department of National Defence. 15 April 2004. Archived from the original on 5 May 2004.
- "CH-136 Kiowa in Canadian Armed Forces". helis.com. Archived from the original on 20 December 2016. Retrieved 11 December 2016.
- "Department of the Army Historical Summary, 1978". United States Army Center of Military History. Archived from the original on 8 September 2004.
- Hawkins, Kari. "Last Kiowa Warrior retires into law enforcement". The Redstone Rocket. AWKINS Aviation and Missile Command Public Affairs. Archived from the original on 2 July 2019. Retrieved 2 July 2019.
- "OH-58B Kiowa". GlobalSecurity.org. Archived from the original on 2 October 2006. Retrieved 26 September 2006.
- "A17 Bell Kiowa". Royal Australian Air Force. RAAF Museum. Archived from the original on 21 December 2016. Retrieved 8 August 2016.
- "Bell OH-58C Kiowa". Flight Research, Inc. Archived from the original on 22 May 2006.
- "Department of the Army Historical Summary, 1977". United States Army Center of Military History. Archived from the original on 1 September 2004.
- "Team Redstone's Role in Operation DESERT SHIELD/DESERT STORM". Redstone Arsenal. Archived from the original on 29 April 1997.
- "MH-58D Combat Scout". Archived from the original on 4 December 2000.
- "Royal Saudi Air Arms". Scramble. Dutch Air Society. Archived from the original on 7 September 2012.
- "Bell Model 406 CS Combat Scout". Jane's All the World's Aircraft 1992–1993. Jane's Information Group, 1992. subscription article, dated 15 July 1992[permanent dead link].
- OH-58 series Kiowa Photo Gallery Archived 16 September 2008 at the Wayback Machine
- "XVIII AIRBORNE CORPS CHRONOLOGY (16- 31 January 1991)". army.mil. Archived from the original on 3 March 2016. Retrieved 23 November 2015.
- U.S. Army Center of Military History. "Gulf War Photo Sampler – XVIII Airborne Corps History Office Photographs – Center of Military History". army.mil. Archived from the original on 24 November 2015. Retrieved 23 November 2015.
- "Hydra-70 Rocket System". Federation of American Scientists. Archived from the original on 4 February 2007. Retrieved 27 February 2007.
- "ASP Motion Base for Stabilized Mounts" Archived 8 July 2013 at the Wayback Machine Department of Defense Small Business Innovation Research. Retrieved: June 2012.
- "Helicopter gunnery tables" Archived 1 June 2012 at the Wayback Machine GlobalSecurity.org. Retrieved: June 2012.
- "OH-58D Kiowa Warrior". Federation of American Scientists. Archived from the original on 25 January 2000. Retrieved 4 October 2006.
- Colucci, Frank (May–June 2013). "Stretching the Scout". Vertiflite. 59 (3): 42–45.
- "OH-58F Kiowa Warrior" Archived 2 May 2019 at the Wayback Machine. OH-58F Kiowa Warrior. military-today.com (online).
- Osborn, Kris (15 March 2011). "Army building new F model Kiowa Warrior". army.mil.
- OH-58F Archived 17 August 2011 at the Wayback Machine Army.mil/Stand-To, 18 May 2011.
- "The Bell OH-58F: Your Mission" (PDF). Bell Helicopter. 2011. Archived from the original (PDF) on 1 November 2011.
- Trimble, Stephen (26 October 2010). "US Army announces new Fox model for Kiowa Warrior". Flight International. Archived from the original on 31 October 2010.
- "US Army completes first OH-58F test aircraft". Flightglobal.com. 25 October 2012. Archived from the original on 31 October 2012.
- Given Budget Uncertainty, Armed Aerial Scout Hovering in Limbo – Nationaldefensemagazine.com, April 2013
- US Army OH-58F makes first flight Archived 28 July 2013 at the Wayback Machine – Flightglobal.com, 30 April 2013
- Army Debates Divestment of Kiowa Warrior; Replacement Program in Doubt – Nationaldefensemagazine.com, 14 January 2014
- Bell receives stop work order for Kiowa upgrades Archived 6 May 2014 at the Wayback Machine Flightglobal.com, 5 May 2014
- Bell Flies OH-58 Block II Candidate for AAS Archived 8 December 2012 at the Wayback Machine Military.com, 19 April 2011
- Bell starts OH-58 Block II flight demo Archived 19 April 2013 at the Wayback Machine Flightglobal.com, 23 October 2012
- Scout Helicopter Competitors to Army: It’s Time for a Flyoff Archived 15 April 2013 at archive.today – Nationaldefensemagazine.com, December 2012
- Outgoing General: US Army Must Continue To Fund Research and Development Archived 17 January 2014 at the Library of Congress Web Archives – Defensenews.com, 14 January 2014
- "World Air Forces 2021". Flightglobal Insight. 2021. Retrieved 4 July 2021.
- "World Air Forces 2018". Flightglobal Insight. 2018. Archived from the original on 6 February 2018. Retrieved 25 August 2018.
- Dominguez, Gabriel (22 October 2018). "Australian Army retires fleet of Bell 206B-1 Kiowa helicopters". IHS Jane's 360. London. Archived from the original on 22 October 2018. Retrieved 22 October 2018.
- "Bell CH-136 KIOWA". canadianwings.com. Archived from the original on 22 January 2014. Retrieved 17 January 2014.
- Royal Canadian Air Force (2 August 2016). "Historical Aircraft". Archived from the original on 14 August 2016. Retrieved 2 October 2016.
- "Special Operations Section". New Jersey State Police (njsp.org). Retrieved 17 October 2019.
- "US Army retires final Kiowa Warrior". janes.com. Archived from the original on 30 August 2018. Retrieved 25 August 2018.
- "Airframe Dossier – Bell OH-58C (FG) Kiowa, s/n 68-16940 US, c/n 40254". Aerial Visuals. www.AerialVisuals.ca. Archived from the original on 23 June 2015. Retrieved 20 May 2015.
- "Kiowa". Pima Air & Space Museum. pimaair.org. Archived from the original on 3 April 2015. Retrieved 20 May 2015.
- "Aerial Visuals – Airframe Dossier – Bell OH-58 Kiowa, s/n 69-16123 US". Aerial Visuals. AerialVisuals.ca. Archived from the original on 23 June 2015. Retrieved 20 May 2015.
- "History – OH-58 Kiowa". Google Sites. Archived from the original on 23 June 2015. Retrieved 20 May 2015.
- de Vries, Wim. "Memorial / Gedenkstätte Point Alpha – Bell OH-58A "Kiowa"". Panoramio. Archived from the original on 23 June 2015. Retrieved 20 May 2015.
- "OH58 Kiowa Helicopter". memorialmuseum.org. Archived from the original on 30 August 2015. Retrieved 10 March 2015.
- "Aircraft Data 71-20475, 1971 Bell OH-58C Kiowa C/N 41336". Airport-Data.com. Airport-Data.com. Archived from the original on 23 June 2015. Retrieved 20 May 2015.
- "Kiowa – National Air Force Museum of Canada". Archived from the original on 24 February 2021. Retrieved 8 March 2020.
- "Bell CH-136 Kiowa". Polish Aviation Museum. Archived from the original on 23 June 2015. Retrieved 21 April 2015.
- "Aircraft Data 72-21256, 1972 Bell OH-58A Kiowa C/N 41922". Airport-Data.com. Archived from the original on 23 June 2015. Retrieved 20 May 2015.
- Harding, Stephen. "Bell H-58 Kiowa". U.S. Army Aircraft Since 1947. Schiffer Publishing Ltd., 1997. ISBN 0-7643-0190-X.
- van Geete, Stephanie. "6-6 Cavalry aircrews field new Kiowa Warrior weapons system." Archived 2 October 2013 at the Wayback Machine www.army.mil Published 6 April 2009. Accessed 16 September 2013.
- Elliot, Bryn (March–April 1997). "Bears in the Air: The US Air Police Perspective". Air Enthusiast. No. 68. pp. 46–51. ISSN 0143-5450.
- Holley, Charles, and Mike Sloniker. Primer of the Helicopter War. Grapevine, Tex: Nissi Publ, 1997. ISBN 0-944372-11-2.
- Spenser, Jay P. "Bell Helicopter". Whirlybirds, A History of the U.S. Helicopter Pioneers. University of Washington Press, 1998. ISBN 0-295-98058-3.
- World Aircraft information files Brightstar publishing London File 424 sheet 2