Targets of Opportunity

by Michael Puttré
Apr. 21, 2005

The shoot-down of a civilian Mi-8 transport helicopter on April 21, killing at least six US passengers, the three-man Bulgarian crew, and possibly two other passengers, was accomplished with a man-portable air-defense system (MANPADS), according to press reports citing the Bulgarian Ministry of Defense. It seems clear that the anti-coalition forces in Iraq that attack helicopters know exactly what they are shooting at and what the countermeasures – if any – are likely to be.

On November 2, 2003, using what is believed to have been a MANPADS, anti-coalition forces shot down a CH-47 Chinook transport helicopter, killing 16 and wounding 20. Two days later, a UH-60 Blackhawk was brought down by a rocket-propelled grenade (RPG) and a RPG hit may have caused a mid-air collision between two Blackhawks later that same, bloody month.

The Chinook, lacking more advanced electronic-countermeasures (ECM) systems, was attacked with an infrared-guided missile. On the other hand, the Blackhawk, which is outfitted with the AN/ALQ-144 infrared (IR) jammer, was hit by a RPG, against which ECM systems are of little, if any, help. This weapon selection indicates that anti-coalition forces in Iraq, far from being unsophisticated, understand their targets – their strengths and possible vulnerabilities – and are choosing means of attack that provide the best possible chance of success.

Protecting the Protectors

Transport helicopters are especially vulnerable, but combat helicopters are not immune to the same array of shoulder-fired threats. US Army Aviation has been redefining combat-helicopter doctrine in light of ongoing operations. "We receive input from the field on an almost daily basis and are conducting face-to-face interviews with units returning from Afghanistan and Iraq to expand upon our current publications," said an official at the US Army Aviation Center (Ft. Rucker, AL). "We also use data from the Combined Arms Center [Ft. Leavenworth, KS] teams sent to OIF/OEF [Operation Iraqi Freedom/Operation Enduring Freedom] to gather lessons learned."

The fruit of these revisions are spelled out in new Brigade Tactical Manuals that emphasize three missions for attack helicopters: division reconnaissance and attack, close-combat attack, and urban warfare. All of these missions reflect insights and lessons from ongoing operations. In a division reconnaissance and attack mission, the Apache will be required to shift back and forth between armed-recce and attack profiles as the battlefield situation evolves. In the close-combat attack mission, Apaches will provide support fires for ground troops. The urban-warfare mission is a specialized close-combat mission involving both support of ground forces and independent attacks and is perhaps, even more than the others, driven by the requirements of the war on terror.

The new missions will require new training methods and new gunnery tables and techniques. In particular, the new doctrines stress "running fire" and "diving fire" over hovering engagements at low altitudes. This will place the Apache out of effective range of certain infantry weapons, such as small arms and RPGs, while also enabling better use of the helicopter’s AN/ASQ-170 Target Acquisition and Designation System (TADS) and AAQ-11 Mk III Pilot Night Vision System (PNVS) sensors for greater situational awareness. Improved situational awareness is counted on to provide crews with advanced warning of threats to them at medium altitudes, such as MANPADS, anti-aircraft artillery, and heavy machine guns.

Opposing weapons develop in an oddly symbiotic relationship with each other. The Hellfire missile, the AH–64 Apache’s primary armament, was developed to enable engagement of armor outside the range of the ZSU-23-4 Shilka mobile air-defense artillery systems that comprised the short-range air-defense system for such forces. The Apache’s nap-of-the-earth (NOE) approach tactics protected the aircraft from missile attack at that range. Therefore, the "hover mode" of engagement was deemed safe, as well as the most effective method of attack.

Although developed for a potential conflict in Europe, the Apache, using hover-mode engagement tactics, was a star performer in the Gulf War of 1991. AH-64As of Task Force Normandy fired the opening salvo of Desert Storm in 1991 when they launched Hellfire missiles at Iraqi air-defense sites in a nighttime "deep-attack" raid. The first cracks in Apache doctrine, however, appeared during Operation Anaconda in Afghanistan in early March 2002. AH-64As of the US Army’s 101st Airborne Division supported ground soldiers of that air-assault division and 10th Mountain Division that were involved in attacks on Taliban and al Qaeda positions in the Shah-e-Kot Valley. The close-quarters fighting, in which targets often were identified only after they had opened fire at ranges of less than a kilometer, was not something for which crews had been thoroughly prepared.

The Apache was a standoff battlefield helicopter, although it was armed to provide escort for airmobile forces in the form of 70mm rockets and a 30mm cannon. However, it was not intended that it loiter in a hot zone, exchanging small-arms and rocket fire with infantry forces. Furthermore, the crews involved in the Anaconda fight said that they had not been trained for running engagements, and that the "hover and pounce" ambush tactics in which they were trained would have gotten them killed.

Yet doctrine dies hard. It took a celebrated failure of a deep attack by 32 Apaches of the 11th Aviation Regiment of the 101st Airborne in Iraq on March 2003 to cause Army Aviation to re-examine its doctrine more seriously. In the March nighttime attack, the Apaches were damaged and driven off by concerted Iraqi anti-aircraft fire, with a loss of one helicopter. The crew was captured, in part because enemy fire was too intense for a combat-search-and-rescue mission to be mounted.

Army Aviation officials are quick to point out that deep attacks are still a good idea in certain circumstances and will remain in the Apache playbook. However, it will be important to ensure that the helicopter remains a useful asset when deep-attack missions are not warranted or advisable. The missions specified in the new Brigade Tactical Manuals are to be undertaken with the assistance of the US Army’s evolving concepts of battlefield networking and support fires. Some of the supporting technologies – such as second-generation, forward-looking, infrared (FLIR) sensors – are already in place. Others, such as the Warfighter Information Network-Tactical (WIN-T), are still in development. There are also new weapons in the pipeline, including the precision-kill version of the 70mm rocket with a semi-active laser seeker, and the Joint Common Modular Missile, which will ultimately replace the Hellfire series. But it is information that the Army sees as its best weapon.

"We are working toward a common operating picture for the future force that will give us better situational awareness," said then Major General Curran, former commanding general of the US Army Aviation Center. (The now Lieutenant General Curran is currently director of the Futures Center US Army Training and Doctrine Command, Ft. Monroe, VA). "But I can guarantee you that the guy who jumps out with a RPG is going to get a shot off. There’s no way that you can come up with a counter for that. The solution is to find out about an area before that happens."

Hunters and Hunted

A celebrated advantage of the battlefield antitank helicopter is that it can see the ground better than enemy vehicles, particularly when those vehicles are "buttoned up" for battle. On the other hand, infantry have perhaps the best situational awareness of all within the tight bubble of their own senses, sometimes enhanced by optical aids. If an enemy can pull the fight into that bubble, then the helicopter will find itself at a disadvantage. During Operation Anaconda, the Apache crews who reconnoitered the landing zones of the air-assault forces could see nothing out of the ordinary. Villages in the environs of the landing zones were reported as being deserted. The whole valley seemed to be asleep. Within hours, enemy troops in the sleepy valley would put five of seven Apaches out of action, although all returned to base to fly again another day. Nevertheless, these five helicopters were rendered combat ineffective with a combination of small arms, heavy machine guns, and rocket-propelled grenades.

FLIR systems offer perhaps the best foundation upon which to build improved helicopter situational awareness. The combination of range and contrast of modern FLIR systems makes them useful for reconnaissance over and above their primary purpose of navigation and targeting. A FLIR sensor on an aircraft, particularly a helicopter, dramatically expands its capabilities as a nighttime precision-strike platform or roving hunter-killer.

In October 2000, the US Army awarded a $78.5-million contract to Team Apache Systems (Mesa, AZ), a partnership of Boeing and Lockheed Martin, to modernize the TADS/PNVS system for the AH-64D Apache Longbow. The first of those systems is currently undergoing field trials. The new sensor system, known as Arrowhead, is expected to almost double the range and resolution of the existing FLIR. The core of the new Arrowhead upgrade is the scanning long-wave detector/cooler assembly that is identical to the US Army's Horizontal Technology Integration (HTI) "B-Kit" FLIRS developed for its ground vehicles. The Arrowhead also employes new image processing algorithms. Other added features will be digital video recording and the ability to transmit still-frame video imagery to the ground commander or to other aircraft via datalink, enhancing the Apache's usefulness as a reconnaissance platform. AH-64D Longbow and AH-64A models will be able to receive Arrowhead as field upgrades.

Lockheed Martin was awarded a $247-million Lot 2 follow-on production contract for Arrowhead that authorizes production of 97 Arrowhead systems for the US Army and foreign military sales customers. The Lot 2 deliveries will begin in July 2006. The Army’s first unit equipped with Lot 1 Arrowhead systems will be fielded in June 2005. The US Army intends to buy 704 Arrowhead systems to outfit its AH-64 Apache fleet by 2011.

The advantages of the long-wave FLIR is that it works much better in battlefield obscurants, like burning oil, pyrotechnic smoke, dust, haze, and the like. Mike Burke, director of international business development for Apache weapons systems at Lockheed Martin Missiles & Fire Control (Orlando, FL), said that this is the main reason why the US Army chose long wave for its original FLIR system for helicopters. A mid-wave FLIR works best in high-humidity environments. An advantage of the long-wave scanning-array FLIR over mid-wave staring-array FLIR today is that a long-wave scanning array gives you better performance in the pilotage function, where the pilots are moving their heads back and forth, so the scene is changing very quickly. A staring array takes longer to catch up, so there's something of a lag when pilots move their sensor turrets back and forth (often by turning their heads).

In an Apache, there are seven displays that the crews can take advantage of. There are the two integrated helmet-mounted displays (IHADS) – one for each pilot – onto which any image can be channeled. The front-seater, who typically fires the weapons (but not always, as Operation Anaconda demonstrated), has a monochrome targeting display that provides the best resolution. And then there are four multi-function displays on the instrument panels (two each, front and back) that are used primarily for monitoring aircraft systems and electronic warfare. "So generally what the crews of an Apache will do is that they will use a multi-functional display to maintain information about the aircraft, and electronic information around them, and they will use the targeting display and pilotage displays to navigate and fight the aircraft," Burke said. "All of these systems working together make a pretty unbeatable combination. No one system by itself is totally infallible."

Burke, a former commander of an Apache brigade and a Gulf War I veteran, said that the ability of a helicopter to cover the battlefield with sensors before ground units roll (or run) over it is of immeasurable value. In difficult terrain, however, it is easy for helicopters to miss well-concealed targets. While having a selection of sensors optimized for specific environments is better than having just one, there is the danger that the crew can become overwhelmed by the volume of sensor data they are receiving. Since it can be shown that hunting for targets is about 99% tedious searching and 1% locating and identifying, some assistance on the image-processing side of the problem would be beneficial.

Lockheed Martin is working on the Assisted Target Detection and Recognition program for the US Army. The goal is to develop image-processing algorithms for identifying targets in a cluttered environment. "We have algorithms that extract targets from multiple sensors, as well as or better than a human might," said Eph Martin, operations analysis senior manager at Lockheed Martin. "The algorithms that we develop are able to examine that information and present to the human operator only the data of interest. So it is actually the equivalent of having five or 10 human beings examining the area that you're interested in instead of just one."

The effort is operating under the Snake Eyes program, which is developing sensors for the Future Combat System. Because the work is primarily in software, the algorithms conceivably could be applied to image processing systems that work with a variety of optical sensors. The source of the input is not particularly important.

An advantage of the algorithm-driven approach, if it can be made to work, is that all of the data from multiple sensors can be fused and examined for targets, as opposed to having human operators cycle through sensors in sequence. According to Martin, the algorithms work with all wavelengths of FLIR, with optical cameras, and with non-optical sensors as well. This is where sensor fusion comes in. "You can take all of those sensors and use them together to increase the chance that you will acquire a target," Martin said. "In fact, we're finding that the more sensors you use and you fuse, the different information that they provide you can far exceed the capability of a human to pick a target out of a cluttered environment."

The algorithms could be used to defeat camouflage that is designed to play on limitations of the human eye and the way the brain processes patterns. This is another area where the multi-sensor fusion comes into play. A camouflage pattern will typically be used to defeat a particular sensor, like the human eye. Some advanced multi-spectral camouflage systems are capable of extending protection into the non-visible ranges. "However, if you have a radar and a FLIR, it is extremely difficult to be invisible to both of those," Martin said.

It is one problem to pick out the lines or the pattern of a vehicle, but it is another thing to pick out a human being. Martin is confident that the algorithms his team is working on will be just as effective at picking a man out among trees and rocks as a camouflaged combat vehicle. And this is what up-close, in-your-face combat demands.