The requirement issued by the US Army in 1974, established the need for a missile capable of ending any present and future armoured threat. A missile was needed that could be launched from helicopters with very high chances of hitting the target thanks to a precise guidance system. The program was known like “Heliborne laser, fire-and-forget missile”, that finally would be known by all as “Hellfire“. In 1978 the US Marine Corps would join the development program, which has since become a joint program.Since 1971, tests and launches of a missile with new guidance systems were carried out, which in October 1976 obtained permission to continue its full development. Rockwell began development of the missile, but at a certain point decided to incorporate an advanced seeker head developed by Martin Marietta. This mechanism consisted of a Cassegrain telescope under a transparent hemispherical warhead that sends signals to the electronic part with a logic microprocessor. The signals are sent in the form of command pulses that act on the missile’s control surfaces. The semi-active laser guidance requires the target to be illuminated by a laser beam in the final phase of the missile’s trajectory.Usually, the launch platform has the laser illuminator, but the missile can “engage” on any other laser beam sent by another designator. In this way, the helicopter pilot only has to launch the missile in the direction of the target and then leave the area (fire and forget). Several Hellfire missiles can be launched simultaneously (bursts) with few seconds of margin between one and the next. In this way, it is only necessary to illuminate with the laser beam the different targets alternately, as the first launched missile hits. This firing mode was used with devastating effectiveness against Iraqi forces during the 1991 Gulf War.The AGM-114 Hellfire measures between 1.63 and 1.80 meters in length depending on the variant and weighs between 45 and 49 kg, of which 8 or 9 kg belong to the shaped charge HEAT warhead. The missile is controlled by 4 small canards located at the front, being able to accelerate up to 13 g thanks to its Thiokol M-120 (TX-657) series solid fuel rocket motor. The maximum speed is between 1.17 and 1.3 Mach (1,433 to 1,592 km/h) and the range is around 8 km.The main elements of the missile are the following, (ordered from front to back): search head composed of an electronic detector, a Cassegrain telescope, a gyroscope, a laser sensor, an impact switch and the guidance avionics, all installed in the front end. Then, (inside the fuselage), there is the warhead followed by the guide section, composed of the fuse, a pneumatic accumulator, a battery, an anti-rotation device and an anti-camber device. Finally, there is the propulsion section, composed of an automatic pilot system, the rocket motor and the control section. On the outside of the missile are the 4 movable control canards, located just behind the search head, and on the part of the engine there are another 4 fixed wings.Hellfire received Operational Use Authorization (OIC) in 1984, and the first 680 AGM-114A Hellfires were delivered during the summer of this year. Since then 11 different variants have been developed, with the same semi-active laser homing (SALH) guidance, except for the AGM-114L HellfireLongBow variant, which features a fire and forget Millimeter-Wave (MMW) radar seeker coupled with inertial guidance. The warheads have also undergone certain variations, although most have been of the shaped charge HEAT antitank type, we can find them of the single type and in tandem type against reactive armour. There are also others of the blast fragmentation/incendiary type for “soft” targets or the multi-function type with reduced explosive weight for low collateral damage. In 2017 a warhead dubbed “Flying Ginsu or Ninja bomb” was secretly developed because instead of an explosive charge it carries 45 kg of dense material with six blades that fly out and literally “shred” the targeted person. This warhead was designed to minimize collateral damage and is only installed on the AGM-114R9X variant.(MQ.1 PREDATOR image). Hellfire variants since its entry into service have been the following, AGM-114A / F-FA / K-K2-K2A Hellfire II / L LongBow with anti-tank warhead, AGM-114 B / C with a warhead against armoured vehicles and ship-borne targets, the AGM-114M Hellfire II with warhead against light vehicles, bunkers, urban targets and caves, the AGM-114N Hellfire (MAC) with a thermobaric warhead against soft-skinned targets, buildings and ship-borne targets, the AGM-114P / P + Hellfire II (for UAS) with warhead against all surface targets, the AGM-114R Hellfire II (Romeo) with warhead against all kind of targets and the AGM-114R9X with a special anti-person warhead (detailed above). In addition, there are two training variants designated as M-34 and M-36 Captive Flight Training Missile.Although the Hellfire missile can be launched from different platforms, including ground attack aircraft, its short range compared to other larger missiles relegated it to a helicopter weapon mainly. With the arrival of UAVs, the missile has become an ideal weapon for them thanks to its low weight and high destructive capacity. A launcher was designed that could be installed in vehicles, (and even allowed firing from the ground), but the great weight of the missile and its high price compared to other mobile systems with similar characteristics have prevented the interest of potential customers.About 30 countries use the Hellfire, mainly those that have the AH-64 Apache helicopter in service, although others have installed it in SH-60B Seahawk naval helicopters, such as Spain (on the image). In fact, the missile can be installed in any helicopter, from the small MH-6 Little Bird to any model of observation and attack. The missile has also been installed in small patrol boats and has also been tested as coastal defense weapon in the style of the Penguin missile.
