You’ve seen the videos. A group of insurgents is up to no good. The black and white video from a thermal sight on an Apache or a Predator tracks them, and then the bright bloom of a missile explosion marks their timely demise. Another Hellfire missile has found its mark.
The AGM-114 Hellfire family of missiles has proven to be a valuable tool for dispatching enemy insurgents, either on foot, in a vehicle, or hiding in a structure. But it didn’t start out with that use in mind.
After the Vietnam War, when the Army returned its focus to the vast Soviet armies threatening Western Europe, one of the prime assets the Army counted on to prevail was the attack helicopter. With the failure of the AH-56 Cheyenne program, the Army had to rely on modernized AH-1 Cobras in the anti-tank role until the AH-64 program could field the Apache.
The Cobra was a fine helicopter, and it was deadly with its TOW anti-tank missiles. But it did have some severe limitations. First, early models of the TOW only had a range of 3000m, later extended to 3750m. Plus, the TOW’s cannister design, while making it an extremely versatile design, limited the diameter of the warhead to a maximum of 6”. Since the penetration of a HEAT warhead is largely a function of its diameter, a wider missile was desirable. And finally, the missile’s long time of flight out to maximum range left the Cobra vulnerable to anti-aircraft fire for up to 30 seconds. Trust me, 30 seconds is a long time when people are shooting at you.
When the Apache was designed, the Army chose to develop an all new missile design to arm it. The Hellfire (originally for Helicopter Launch and Leave) missile was a semi-active laser guided missile launched from rails attached to the stub wings under the Apache. With its 8000m range, the Hellfire could be launched outside the range of most of the common Soviet anti-aircraft weapons. It’s laser guidance meant that the launching aircraft could guide the weapon, or let another Apache or a scout helicopter guide the weapon, or even an observation team on the ground. The Hellfire’s wide diameter tandem HEAT warheads were sufficient to blast through any existing armor.
The Apache/Hellfire combination proved just how deadly it could be during Desert Storm, where hundreds of Apaches fired thousands of Hellfires with devastating effects on the Iraqi Army and the Republican Guard. I have a very clear memory of watching an Apache battalion eviscerate an Iraqi armored brigade in less than 15 minutes. But while the early Hellfire was a very effective weapon for its designed role, the war on terror showed something more was needed. There are relatively few terrorists mounted in tanks. As mentioned above, the more likely targets are troops in the open, in light vehicles, and inside structures. HEAT warheads work by directing so much of their energy into a very tight direction to punch through, and they produce relatively small amounts of blast effects and fragmentation in other directions. That means that even near misses might not kill or wound terrorists. The answer to that problem, of course, is to change the warhead on the Hellfire. By swapping out the HEAT warhead with a blast/fragment warhead or a thermobaric warhead, The Apache now had a weapon far better suited to its new role of swatting bad guys in the War on Terror.
As you may have noticed, the Hellfire is also mounted on more than just the Apache helicopter. It can be mounted on the OH-58D Kiowa Warrior scout helicopter, the modernized Marine AH-1W and AH-1Z Cobras, Navy MH-60 helicopters, Predator and Reaper UAVs, and several other aircraft. It can even be fired from a ground mount. Sweden uses a locally produced version as an anti-ship weapon fired from a small portable ground mount.
A word about range. While the maximum range is usually listed as 8km, that’s from a low altitude. Fired from 20,000 feet off of a Predator, or 50,000 from a Reaper, the range would likely be much greater.