OH-58A Kiowa Helicopter was a Pioneer (Part-2)

For the First Time in History, a Cable Cutter System is Integrated into a Helicopter, OH-58As

For the first time in history, the Cable Cutter System was used in a helicopter. In 1969, when this system was first used, the OH-58A Kiowa was preferred as a helicopter. This system was designed to cut telephone cables and electrical wires that the pilot could not see or avoid on the flight line during landing, take-off, and low-level flight profiles, allowing the helicopter to continue flying safely. The Helicopter Cable Cutter System or Wire Strike Protection System is one of the ways to protect the helicopter in the event of a wire strike by providing the ability to cut a cable or wire before major damage to the helicopter occurs. The system has been developed to reduce the chance of a cable or wire entering the cockpit and to reduce the chance of damage to the flight controls located in the cockpit. The cutter, located above the helicopter, reduces the possibility of cables and wires damaging the rotor and blades. The system can protect 90% of the helicopter's frontal area.  

This system has been successful. It has saved lives and lives in accidents during low-level flight, landing or take-off. This safety design in the OH-58A Kiowa model has influenced other helicopter manufacturers; other manufacturers other than Bell helicopters have made this safety equipment standard equipment in the helicopters they produce to contribute to the safe flight of their helicopters.

Integrating Radar Warning Receivers on OH-58A Helicopters

By the 1970s, the US Army wanted to improve the capabilities of its reconnaissance helicopters, but realized that the OH-58A was not powerful enough for operations at higher altitudes and high temperatures.

Seeking a new reconnaissance helicopter, the Army formed a special task force known as the Advanced Scout Helicopter (ASH) Program at Fort Knox in March 1974. Work began with the Army's requirements in mind: a new helicopter capable of operating day and night, in adverse weather conditions, and compatible with advanced weapon systems planned for development and fielding in the 1980s. Unfortunately, the ASH program could not be implemented due to the refusal of Congress to fund the program in the 1975 fiscal year budget and its closure in September 1976.

With the end of its intervention in Vietnam, the United States refocused on Central Europe, where its NATO allies were awaiting a Soviet Army invasion. A possible Soviet-US war in Europe was envisioned as a conventional war far more dangerous than the war against the Viet Cong guerrillas in Vietnam. This was due to the emergence of MANPADS, a surface-to-air MANPADS system capable of hitting targets at a range of 3.7 km in the Arab-Israeli wars. The potential damage that a portable, shoulder-fired air defense system (MANPADS) could inflict on helicopter operations was alarming. This weapon was the Soviet-made 9K32 Strela-2 (NATO code name SA-7 Grail). The lethality of the 9K32 Strela-2 was particularly poor against jet aircraft. In the Arab-Israeli Wars. In the Middle East, the Egyptians and Syrians used the low-altitude Strela-2, the ZSU-23-4 Shilka radar-tracking mobile anti-aircraft guns and the low- to medium-altitude 2K12 Kub (NATO codename SA-6 Gainful) to tear Israeli fighter jets to pieces. The Arab countries had established a kind of air defense umbrella overhead to reduce and break the influence of the Israeli Air Force. 

In response to these new threats, in 1976, the US Army equipped a total of three OH-58As with AN/APR-39A Radar Warning Receivers to alert the crew to the presence of NVG (Night Vision Goggles) compatible air defense radars. Panels and reduced reflection canopy glass. As power is always a welcome addition to any helicopter, 420 Hp Allison T63-A-720 engines were installed under the engine cowling. Thermal exhaust suppressors were installed. After several years of testing, upgrades were approved for a total of 575 more airframes, all of which were reclassified as OH-58C Kiowa in May 1978.

The OH-58C Kiowa's upgrades were certainly a boon in terms of kill avoidance, but they did not improve its ability to find things to kill. Reconnaissance helicopters in Vietnam relied solely on the pilots' own eyes and hand-held binoculars to spot Viet Cong operating in the jungle. Once the pilots of the reconnaissance helicopters spotted the Viet Cong, they radioed to armed UH-1B/C Hueys or attack helicopters AH-1G Huey Cobras, which used their speed and maneuverability to evade small arms and anti-aircraft machine guns to destroy the Viet Cong with volleys of their own guns and rockets.

On the European stage, however, the expected enemies were Warsaw Pact tanks, armoured vehicles, and mobilized tracked or wheeled anti-aircraft systems that could move simultaneously with the Warsaw Pact tanks and armoured vehicles, which had to be detected at a distance and intercepted at a safe distance with missiles called ATGMs (Anti-Tank Guided Missile), as well as partially providing them with an air defence umbrella. For helicopters to conduct reconnaissance from an unsafe distance was literally suicidal in the face of ground-based air defenses and fighter jets that could be in the area if they were detected. Without any onboard target detection devices, a Kiowa crew could probably recognize the blurred outlines of an invading army. However, they had to ask the AH-1s to risk earlier exposure to danger by utilizing the TSU (Telescopic Sight Unit) feature on the AH-1 attack helicopters for better target acquisition. In the late 1970s, the existing head-mounted image intensifiers on the OH-58A and OH-58C were only useful for navigation and were not capable of night operations as they did not detect long distances. Pilots found that OH-58Cs with flat-plate canopy windows caused an 18% reduction in visibility, tended to crush inward when the flight speed exceeded 80 knots, and were prone to condensation in rainy conditions.

The decision was then taken in 1979 to postpone the development of a new helicopter. Despite these adverse developments, the modification of existing helicopter airframes became known as the Army Helicopter Improvement Program (AHIP). Bell and Hughes once again redesigned the helicopter to compete for the contract. Bell Helicopter Textron was awarded the development contract in September 1981 and the first prototype flew in 1983. The helicopter, known as the OH-58D, entered service in 1985 and fulfilled the role of the Army's multipurpose helicopter used for troop transport, medical evacuation and external lifting missions using the cargo hook. This model would eventually become the model used today, known as the OH-58D Kiowa Warrior. An interesting anecdote is that initially all OH-58Ds were rebuilt as OH-58A, but the mere concept of "rebuild" may be insufficient. Bell's Orson Hurwell said, "We take the old helicopter and turn it into a bare shell. Then we cut off the tail boom and make a completely new one. We throw away the rotor and put on a new rotor. We put in a different drivetrain, a different engine, a different tail rotor."

There was a reason why the US Army took such modest steps with the OH-58C modification: In the 1970s, budget priorities were focused on the Utility Tactical Transport Aircraft System (UTTAS) and Advanced Attack Helicopter (AAH) programs that gave birth to the Sikorsky UH-60. Blackhawk and the McDonell Douglas (formerly Hughes) AH-64 Apache. In 1981, the Army Helicopter Improvement Program (AHIP) provided the Kiowa with the tools it needed to detect long-range targets and identify them for attack helicopters and artillery.

What made the OH-58D Kiowa Warrior stand out as a reconnaissance helicopter was the development of the Mast Mounted Sight (MMS). The MMS has been the primary focus for improving the helicopter's capabilities. The MMS gave the helicopter additional mission capability through improved visibility in adverse weather conditions, as well as target detection and laser designation, both day and night. Before the Kiowa, reconnaissance helicopters could not perform and fight at night. Back then, they only had flares to light up the night sky.

The MMS provided Kiowa with the tools it needed to detect long-range targets and identify them for attack helicopters and artillery. The most important of these was the Mast-Mounted Vision System (MMS), which looked like a beach volleyball ball resting on a vibration isolation apparatus that housed a 12x magnification TV camera, thermal imager, laser rangefinder and laser designator. To support the weight of the MMS and provide more responsive performance when flying the Nap of the Earth maneuver, a 650 hp Allison T703-AD-720 now spun a four-blade composite rotor through upgraded propulsion systems and transmissions. The cockpit instruments of the aircraft, unsurprisingly designated OH-58D (Model 406), were mounted on multifunction displays to transmit MMS images and range measurements to pilots.