Air Weapons: Little Laser Guided Missiles Join The Infantry

Archives

June 2, 2018: First proposed back in 2006, an American firm has finally put together a lightweight, vehicle based system, using the 70mm APKWS II (Advanced Precision Kill Weapons System) laser guided missile. Called Fletcher, it consists of a four tube launcher weighing 13.6 kg (30 pounds) empty. The launcher is two meters (78 inches) long and 30cm x 30cm (11.8 inches). Fletcher uses one of the smaller (lighter) rocket motors and warheads, thus each APKWS used by Fletcher weighs 11.3 kg (25 pounds). A Fletcher launcher with rockets weighs 59 kg (130 pounds). The compact and lightweight Fletcher launcher can be mounted on any vehicle that normally mounts a heavy (12.7mm) machine-gun or RWS (Remote Weapons Station). Current versions of Fletcher are being marketed to special operations forces that use many lighter off-road vehicles. For example, DAGOR is a two ton light truck that can carry 1.4 tons or nine troops. It can be carried inside a CH-47 or slung under a UH-60 helicopter. DAGOR can also be dropped via parachute and be ready to roll within two minutes of reaching the ground. Vehicles like DAGOR and even lighter ATVs (all terrain vehicles) are popular with special operations troops and Fletcher was designed to provide these forces as well as regular infantry with lightweight laser guided missile systems,

Adapting aircraft weapons is not unusual. The United States has adapted heat seeking (Sidewinder) and radar guided (AMRAAM) air-to-air missiles for use on anti-aircraft ground vehicles. It is rare to adapt air-to-ground missiles for use on ground vehicles.

APKWS are basically 70mm laser guided rockets. Normally each APKWS weighs 15 kg (32 pounds) and is basically a 70mm unguided rocket with a warhead and guidance system attached. The guidance system consists of a laser seeker and moveable fins, battery and microprocessor to guide the rocket to the reflected laser light the laser designator is bouncing off the target. These missiles usually have a 2.7 kg (six pound) warhead, and a range of about five kilometers when fired from the ground (and about twice that when fired from the air).

APKWS has always been able to use laser designators on a helicopter, or with troops on the ground. The laser seeker can actually see reflected laser light out to 14 kilometers but the rocket motor in most 70mm laser guided rockets is only effective at between five and ten kilometers. Fletcher can use slightly heavier APKWS rockets that have a longer range but that won’t happen until users indicate a need for it.

Adding laser guidance to 70mm rockets seemed like an obvious concept but it took many years to develop a reliable system. The 2.75 inch (70mm) rockets were developed during World War II, as an air-to-air weapon for use against heavy bomber formations. The Germans had developed a similar and very successful weapon (the R4M). Before long it was noted that neither the Japanese nor the Germans had any heavy bombers, so the U.S. 70mm rocket was switched to air-to-ground use. Actually, the 70mm rocket was retained for air-to-air use into the 1950s, but it was never successful in that role. The 70mm rocket became very popular in the 1960s when it was discovered that the weapon worked very well when launched from multiple (7 or 19 tube) launchers mounted on helicopters. The 108-138m cm (42-55 inch) long rockets could be fired singly or in salvoes and gave helicopter pilots some airborne artillery for supporting troops on the ground. There are many variations in terms of warheads and rocket motors. Some versions could go over 10 kilometers.

Since the 1990s several firms have spent years to figure out how to turn 70mm (2.75 inch) unguided rockets into laser guided missiles. Most were designed to use existing the Hellfire missile fire control system. Several successful designs entered service by 2010. The APKWS began as a 2002 effort by an American firm, which could not get it to work. British firm BAE took it over and got it to work by 2007 and partnered with the American firm to sell it. APKWS, like its competitors, was built to be compatible with existing laser designators, and aircraft equipped to use Hellfire missiles. For helicopters, APKWS could also be adapted to use 7 or 19 tube launchers long employed for the unguided rockets. The big advantage of all these 70mm missiles is that it is one fourth the weight of a Hellfire, and one fourth the cost. That means AH-64s burn less fuel carrying them, and APKWS is as effective as a Hellfire in, for example, destroying the hundreds of small armed boats Iran plans to use in any war with the Arab states on the west coast of the Persian Gulf. But there are already many similar weapons available for this and few nations want to add what they consider a redundant weapon system.

This weight advantage made ground use attractive for specialized troops, like Special Forces. But before anyone would even consider a ground-t0-ground 70mm guided missile there had to be evidence that the air-to-ground version worked. The 70mm missiles eventually found some customers. In 2010 the U.S. Marine Corps tested APKWS II on their helicopter gunships and were so impressed that they bought many more. The marines armed their AH-1W helicopter gunships with the guided 70mm rockets and in 2012 marine AH-1Ws have fired over a hundred APKWS II in Afghanistan and none of them missed.

APKWS was adapted for use from a number of helicopters as well as fixed wing aircraft like the A-10, F-16, AV-8B, CN-235 gunship and A-29. APKWS has been exported to Iraq, Lebanon and Jordan and was used in 2017-18 in the fight against ISIL (Islamic State in Iraq and the Levant) in Iraq. There are now a growing number of 70mm air-to-surface and surface-to-surface versions in production or development.

Fletcher, for example, won’t be shipping until late 2018 or early 2019. Developing a guided 70mm rocket took so long because the manufacturers underestimated the technical difficulties of getting the laser seeker and flight control mechanisms into that small a package, at a weight and price the customer could afford. The price of the new 70mm missile is now about $30,000 each. This is typical for these weapons and about a third less than a smart bomb and less than a third of what a Hellfire missile costs. Tests have shown that the ground based 70mm missile is reliable, thanks to over a decade of development and combat use of the air-to-ground version.

In tests the APKWS hit within a meter (a few feet) of the aiming point and has proved an excellent weapon for UAVs, especially since you can carry more of them. The launcher for carrying these missiles is designed to replace the one for Hellfire but can carry four missiles instead of one. UAVs can carry more of the smaller missiles, typically two of them in place of one Hellfire. It was work on this lightweight APKWS launcher and associated equipment that made it easier to design and build Fletcher.