Helicopters: Hunters, Not Victims
by Kathleen Kocks
Encounter an attack helicopter, even during the innocence of an airshow, and there’s no doubt that you are facing a predator.
From nose to tail, it has the body of a killer. It has the eyes (target-acquisition system), ears (electronic-warfare and countermeasures suites) and teeth (weapons) of a killer. Its traits include agility, survivability and speed. It does its job alone or multiplies its strength by working in a pack.
Confuse it not with a helicopter that began life unarmed, but subsequently acquired weapons. Such pretenders are sheep in wolves’ clothing, compared to the attack species. From concept to conception, attack helicopters were bred to kill. Their brute force is clearly evident. Less evident is their newest, most dreadful weapon: information technology. Thanks to advanced defense electronics, modern attack helicopters are not only hunters, but also gatherers of battlefield intelligence.
“Besides its weapons, the key advantage of a modern attack helicopter is that it is an information-technology platform, having total systems integration of all its sensors and being able to process all the data available,” says Bradley Rounding, Boeing’s domestic business development manager in Mesa, AZ. “Its value depends on how the crew uses the systems and how that information is passed throughout the battlefield.”
When used fully, this information technology delivers situational awareness in the cockpit, among battle formations and to command posts. The result: Today’s attack helicopter can bestow upon commanders an omnipotent battle advantage.
THE ARMED EVOLUTION
Fitted with advanced electronics and weaponry, fourth-generation attack helicopters aren't nearly as vulnerable as their predecessors. (Boeing photo)
Even visionaries couldn’t foresee this evolution when the helicopter entered military service late in World War II. The thought then of arming the spidery, underpowered contraption was ludicrous, yet necessity soon drove commanders to strap weapons on the things. The first sporadic instances occurred during the Korean War. In Operation Bumblebee in 1951, for example, a few Sikorsky H-19s transporting US Marines to the front line were equipped with rocket launchers to provide suppressive fire.
Credit for routinely arming helicopters goes to the French. The raison d’etre occurred during France’s 1954-62 conflict in Algeria against the Armeй de Liberation Nationale (ALN). ALN was the military arm of the Moslem-led Front de Liberation Nationale (FLN), which was seeking Algeria’s independence from France. At first, French helicopters (used for transport) were relatively unscathed by the poorly trained and poorly armed rebels. But by 1956, the rebels had traded in their rifles for machine guns and had learned how to lead a volley when shooting at a helicopter. French attempts to use airplanes to escort the hapless helicopters proved impractical. Thanks largely to one avant-garde officer, Colonel Felix Brunet, the French armed their helicopters. They first equipped Sikorsky H-19s with an array that included machine guns, bazookas, cannons or rocket launchers. Then they armed Vertol H-21s, Sikorsky H-34s, and SNCASE Alouette IIs, which became France’s mainstay armed helicopter in Algeria.
Although the French lost Algeria, they learned the value of helicopters for heliborne assault, command and control, reconnaissance, and fire support. It was here that a new concept called “airmobility” dawned. For the French, the helicopter delivered four major advantages: surprise, concentration of force, flexibility and speed. “The most significant and lasting innovation was the installation of guns, rockets and missiles on some helicopters....In fact, the arming of helicopters turned out to be more successful than anyone had dared hope and confounded the skeptics,” writes John Everett-Heath in his book Helicopters in Combat, The First Fifty Years.
These helicopters, plus the Bell UH-1 Huey, made up the first generation of combat helicopters. The second generation arrived in 1965, when Bell Helicopter developed the AH-1G HueyCobra. It was based upon the UH-1 Huey, but had a narrow fuselage and a frontal area 60-percent less than the Huey. Fast and nimble, the AH-1G entered US Army service in Vietnam in 1967 and quickly proved the its value.
The third and fourth generation of helicopters represent those designed from the ground-up as combat helicopters. The current progeny includes:
From the US: the Boeing AH-64D Apache Longbow and the upcoming Bell AH-1Z SuperCobra and Boeing-Sikorsky RAH-66 Comanche;
From Europe: Agusta’s A129 International and Eurocopter’s Tiger;
From Russia: Kamov’s Ka-50/52 Hokum and Mil’s Mi-28N Havoc; and
From South Africa: Denel’s CSH-2 Rooivalk.
Of these, the Apache Longbow and the Comanche are considered fourth generation. They embody the best in advanced engineering, materials, electronics and systems integration.
The CSH-2 Rooivalk represents the third generation of attack helicopters.
(Denel Aviation photo)
The equipment aboard current attack helicopters is increasingly top-notch. In many of the newer cockpits, large, color multifunction displays have replaced a swarm of analog gauges and switches. Man-machine-interface engineering and menu-driven software have produced simplified data presentation, using graphics and icons. In those helicopters having it, total systems integration has exponentially multiplied their electronic capabilities and further reduced crew workload. On-board communications systems are increasingly digital, multiband, joint-force-compatible and securely encrypted. Data links that transmit digital data and imagery are on fourth-generation models and planned for others. Navigation systems feature integration of the GPS with inertial or Doppler navigation, creating the most accurate navigation ever. Also on board is ground-mapping radar that enables terrain-following capabilities, with data presented on moving maps in the cockpit or on the pilots’ headup displays. Target-management systems include improved TV sensors, infrared sensors and laser acquisition/designator sensors. Other features are aided target recognition, classifying and prioritizing, plus automatic handoff of targeting data to appropriate weapons. Armament spans from chain-gun cannons to rockets to laser-guided and fire-and-forget missiles. Threat-avoidance systems feature all countermeasures any fighter could desire. Airframes have radar-resistant profiles and coatings, and engines have infrared suppressor systems. Aircraft-survivability equipment (ASE) includes a blue-ribbon menu of radar and laser warning receivers, missile launch and approach detectors, radio-frequency interferometers, IR and radar jammers and chaff dispensers.
It is impossible in the scope of this article to enumerate the attributes, acronyms and AN nomenclature of the newest attack helicopters. Instead, have a bit more fun by flying a virtual mission to see what all this whiz-bang technology does. Your steed is the Apache Longbow. We chose it because of its brute force, its information technology and its systems integration. No other attack helicopter in production has these capabilities; in fact, the Apache Longbow is the world’s only fourth-generation combat helicopter in the field today.
Various Boeing experts and US Army sources helped us craft a mission from a pilot’s viewpoint. As a former Army AH-64A pilot, Boeing’s Rounding contributed some operational perspectives. “What makes the Apache Longbow stand out,” Rounding states, “is not necessarily the equipment it has on board, which any aircraft can use, but how that equipment is integrated. Apache Longbow is the only totally integrated weapons system of its kind, including total systems integration of the electro-optical and electronic sensors, which give the crew the capability to run the full range of operations.
“Thus, Apache Longbow is a huge mission equipment package having extensive information processing and transferring capabilities. And because all its systems — the weapons systems, ASE, and other systems — are integrated through the cockpit, the Apache Longbow crew has a situational awareness that attack helicopter pilots never had before.”
TAKE A FEW NOTES
Before your virtual mission begins, a short briefing is needed:
Once a target is located using the Apache's sensors, its devastating array of weaponry can be brought to bear. (Boeing photo)
• Your helicopter is a two-seat, twin-engine model capable of cruising at 120 knots while loaded or a combat mission. The seating is tandem, with the copilot/gunner in front and you, the pilot, in the rear.
• All major on-board systems are dual redundant and many systems are isolated from one another to further ensure survivability. The General Electric T700-GE-701C engines deliver enough power for the helicopter to fly on one engine; the transmission can run 30 minutes dry; and the rotor blades have a ballistic tolerance proven to take hits from 27mm ammo and still keep the Apache Longbow flying.
• As for crew protection, the airframe has armorplating near the cockpits and the seats are crashworthy. In a crash, the landing structure absorbs energy and the chin-mounted gun moves away from the cockpit. If the engines fail completely, you can autorotate and safely land. (One of the helicopter’s least understood, yet best safety features, autorotating means the pilot can still land a helicopter with no engine power. This is because the rotor blades continue to turn as the helicopter descends, building up enough wind resistance to provide some lift and enable the pilot to control and land the helicopter with no forward or downward impact. This is much like how a twirling maple seedling gently descends to the ground, rather than plummeting like an oak’s acorn.)
• Both cockpits have two large, flat-panel, color multipurpose displays (MPDs), made by AlliedSignal and powered by the Apache Longbow’s new high-speed, 32-bit processor. They display moving-map data, tactical situations, fire-control and weapons management data, communications, video and airframe-related data (like engine parameters). You can also view flight and tactical information through your headup display. The different data is accessed through menu-driven software, akin to Microsoft WindowsTM; menus can be selected via switches alongside the MPDs or via a “mouse” button on the collective flight control. Most data will be displayed graphically and will only include the information you need to see (i.e., data management by exception). If you want to see the data supporting a graphic, a click of the mouse will reveal it. If an anomaly occurs (say, an engine over-temp), the display will indicate it and show corrective action.
• Your flight controls consist of a collective for one hand, a cyclic for the other hand and two foot pedals. The simple explanation of their workings is that the collective and cyclic (which look like joysticks) control the main rotor system and the foot pedals control the tail rotor. The cyclic and collective contain buttons and switches that allow you to manipulate the data on the MPDs, operate all the sensors and fire all the weapons without taking your hands off the flight controls. Your helicopter also has a new automatic flight control system.
• Two key systems from Lockheed Martin will help you locate, acquire, designate and destroy targets. The Apache Longbow’s circular mast-mounted sight contains the Longbow millimeter-wave fire-control radar, and the nose-mounted sight contains the target-acquisition designation sight/pilot night-vision sensor (TADS/PNVS), featuring daylight TV and FLIR sensors, plus laser rangefinder. Just below the fire-control radar is the radar-frequency interferometer (RFI), which detects electronic signals emitted from air-defense vehicles.
• Your advanced communications include SINCGARS radios for secure voice communication and a data link that uses the improved data modem (IDM), delivering digital data transmissions at 14,000 baud. For navigation, you have two embedded GPS/inertial systems (EGIs), plus an auxiliary Doppler system; your Longbow radar also has a terrain-pilotage mode, enabling terrain-following, nap-of-the-earth flight.
• Your armament includes a chin-mounted 30-mm automatic cannon, up to 76 2.75-in. rockets and up to 16 Hellfire Longbow fire-and-forget missiles. Other usable missile types include Stingers, Mistral, and Sidewinders.
PLANNING THE WORK
Apache Longbows are equipped with the Longbow radar and a comprehensive ASE suite to warn their crews of any danger lurking on the horizon. (Boeing photo)
Night creeps in as your mission begins. Your first stop is the US Army’s Aviation Mission Planning System (AMPS). Gone are the grease pencils and bulky navigation charts, because the AMPS allows you to plan your mission electronically. It takes into account not only route and weather information, but also the current battlefield scenario, which is being gathered by various intelligence sources and fed into the AMPS.
As is routine, you plan two missions: a primary mission and an alternate mission. You then download all data for both missions onto a small data module, which will slip into a black box in the cockpit. Your mission plan will be pumped onto the moving map display during the flight. “Of note, you only have to do that mission planning for one aircraft,” Rounding remarks. “Because AMPS data on the card is digital, a pilot can press a button in the cockpit and transmit all the mission planning data through the Apache Longbow’s IDM to his wingman, who can then also fly the mission.”
Slipping this module into your flight-suit pocket, you stroll out to the helicopter. In tonight’s scenario, you are part of a four-ship formation with three other Apache Longbows; in this mission, two are serving as scouts (the “light” team) and two as guns (the “heavy” team). You climb into the cockpit and begin the starting process, which is automatically managed and monitored to properly start the gas turbines and quickly get the rotors up to 100 percent. You lift off and slip into the night.
WORKING THE PLAN
You are flying in formation with the other helicopters, in the black. Because of increased situational awareness, you are confident about flying in formation at night without lights and maintaining separation from each other. Flying in the black also lowers your probability of intercept. One Apache Longbow is flying with its radar set in the air-targeting mode, scanning the airspace above and across the horizon for any enemy activity. Meanwhile, you’re using your Longbow radar in the ground-mapping mode, which delivers terrain-profiling for your covert nap of the earth flight. Your comprehensive ASE suite is on guard, alerting you in advance of enemy fire. In the near future, Apache Longbows could begin receiving ITT Industries’ Suite of Integrated Radio-Frequency Countermeasures (SIRFC). Tested during 1999 on Apache Longbows, SIRFC uses radar warning, active radar jamming and passive RF target detection and classification. SIRFC- derived information, such as threat locations and ranges, will be overlaid on the digital moving map, enhancing situational awareness and improving survivability. Your first line of defense is your radar-frequency interferometer (RFI), which is sniffing out some 16 km, seeking enemy air-defense emissions. Consisting of individual units mounted around the rotor mast, the RFI is integrated with the Longbow radar. Again, total systems integration is at play.
The RFI picks up the first signs of an active radar pulse and identifies the enemy target. The target’s tactical situation is displayed on your MPD and a cued search is initiated. A press of a button slews the Longbow radar toward the threat. Simultaneously, a Longbow Hellfire is being prepared for firing. Being at eight kilometers from the threat, you are within range of the Longbow radar and the Hellfire Longbow missile. Target range information is passed from the helicopter’s radar to the missile’s onboard radar; if you choose to pull the trigger now, the fire-and-forget missile is launched.
“During Task Force XXI exercises at Fort Irwin, the crews of the two participating Apache Longbow prototypes would be flying along at treetop level and the RFI could pick up the electronic signals from the opponent’s air defense at long range,” Rounding says. “The Apache Longbows just kept going in, and when within the eight-km range of the Hellfire missile, they put out the air defense. Before long, those two Apache Longbows were routinely leading the fleet. When the opponent’s air defense finally discovered what their problem was, they stopped turning their radars on. That says something about the power of the Apache Longbow.”
SEND OUT A SCOUT
As your formation approaches the enemy’s position, the IDM receives new information about the battlefield scenario from the JSTARS platform. Your commander knows where you are and what you are doing because you’ve been transmitting your flight data to him electronically at regular intervals. The updated battle information is incorporated into the flight plan being presented on the moving map, and you see that the enemy has shifted its position slightly. The new location is tightly confined and will only allow for one helicopter to approach for a radar scan to get targeting information.
Flying one of the scout ships, you draw the straw to do the work. Flying low and getting closer in, you pop up slightly to expose the Longbow radar for a sweep of the battlefield. Emitting less power than an open refrigerator door, the Longbow radar scans more than 50 sq km in less than 15 sec. It has taken in all stationary and ground targets, gathered their location, speed and heading. Using aided target recognition algorithms, Apache Longbow systems determine which images are military-significant targets. It classifies which targets are tracked or wheeled vehicles, air-defense units, airplanes or helicopters. Targeting data for up to 128 targets can be displayed on the crews’ MPDs and/or sent to the commander.
You’re playing commander for this mission, so you will be the battlefield manager and won’t plan to fire unless needed. It’s time for you to assign battle sectors and determine fire distribution among the formation’s other helicopters. By indicating to the helicopter’s systems that fire distribution will be among three helicopters, you use the mouse to put a box around the targets, press a button, and the box is divided into three sectors. You then use the IDM to send the target information to each other aircraft.
The crews move their helicopters within range of their weapons. On their MPDs, they see that the radar has classified and prioritized the targets by putting symbols over them. The crews only have to agree to pull the trigger to shoot the target. They don’t even have to expose their helicopters to fire. However, it’s the Army’s policy that crews must still visually identify the target. No problem. Here, the TADS/PNVS comes into play. The crews select the FLIR or TV sensor, then press a button on the control. The TADS/PNVS slaves to the point where Longbow radar picked up the target. Once the pilot has eyeballed the target, he then has visual identification and can elect to destroy it. The pilot can also slave any weapon system to any sensor input (FLIR, TV or radar), push another button and the sensor passes the targeting information to the weapon system. Of note: The teaming of technology and systems integration has resulted in an intriguing side benefit for the unguided chain-gun rounds and rockets. Because Apache Longbow’s systems can take into account a much wider range of aircraft parameters and targeting conditions, aiming calculations and firing results have improved. This has increased the accuracy of the gun tremendously.
An even more important benefit of the Apache Longbow’s defense electronics is the reduced chance of fratricide. Before firing any weapon, you can transmit a query via the IDM, asking for a signal from all friendly Apache Longbows indicating their position. Thanks to the Apache Longbow’s two embedded GPS/inertial navigation systems (EGIs), each aircraft can respond with supremely accurate positions. The responses result in a MPD presentation of symbols designating the location of friendly forces. “No-fire zones” can be established on these locations, preventing any weapons fire upon them.
Back at the battle, the Apache Longbow crews have visually confirmed the targets and assured none are friendly forces. It’s time to destroy the enemy. Expending the ammo is quick work, particularly for the missiles. No more lasing or manually tracking them; push a button and the aircraft systems not only select the missile, but select it from whichever side of the aircraft that is most beneficial to flight performance.
One large target — too big for the Hellfire — remains. You’ve used the IDM to send that knowledge to the commander, who’s ordered you to handoff the targeting information to a fast mover with the heavy missile for the job.
Time to go. As your formation turns homeward, you transmit final mission data via the IDM back to the commander. Data includes where you flew, which rounds you expended and which targets were serviced or not. Maintenance-related data is also forwarded. If the helicopter needs maintenance, the right people with the right tools and material will be ready to work on your helicopter when it lands.
It’s been a successful sortie. Thanks to the integration of some of the world’s best defense electronics, weaponry and helicopter technology, you’ve shown that helicopters are definitely hunters, not victims.
Comanche: Taking Invincibility Further
The stealth characteristics of the Comanche will allow it to "See Without Being Seen." (Boeing photo)
During 2006, US Army Apache Longbows will be joined by Boeing Sikorsky RAH-66 Comanches. The Apache Longbow will deliver heavy attack and the Comanche will deliver armed reconnaissance. Because the Apache Longbow can perform attack and reconnaissance roles and is already a potent information- technology platform, many people have wondered how the Comanche will be better. The difference isn’t so much in electronics — although the Comanche will have more advanced electronics than the Apache Longbow — but in its airframe. In other words, no matter how many electronic gadgets you put on the Apache Longbow, you can never change its airframe to make it as low-observable as the Comanche. Having the motto “See Without Being Seen,” the Comanche has a far-better capability to infiltrate enemy positions covertly, accomplish missions and survive.
“The simple answer about the difference between the Comanche and the Apache is a matter of technology. We added in all those technologies that have come since the Apache was designed,” begins Art Linden, program director of the Boeing Sikorsky Comanche office. “Apache is 1970s technology in design. Comanche, designed 25 years after Apache, is the next generation of technology.
“We have designed a helicopter with low observables and a low radar signature — the Comanche’s radar signature is 300 times smaller than the Apache’s. It also has retractable landing gear, flush antennas, retractable weapons-bay doors and similar things.
“When the Apache was in development, people were just starting to recognize a need to defeat heat-seeking missiles. With Comanche, we ended up with one fourth the exhaust signature of the Apache and the Black Hawks when they have suppressors. We were also allowed to grow the aircraft to make it quieter by using a five-bladed rotor and a larger fantail and [to] reshape the helicopter to get its radar signature down.
“How did we sort out how quiet to make Comanche? The right answer was to build Comanche so that no matter what detection system the enemy uses, then Comanche is not detectable from that range.”
As for electronics, the Comanche carries a second-generation FLIR that will see twice the distance of the currently fielded FLIR. It also has image-intensified TV and will carry an improved and smaller version of the Longbow radar. Thus the Comanche’s systems can see twice as far and look at four times the battlefield area than the Apache Longbow can, giving it far more standoff capability. “The sensor scans the battlefield in under 10 seconds, and the computer goes through its FLIR, II TV and next-generation Longbow, performing electronic scanning rather than using the mechanical antenna that Apache Longbow has. As far as the Longbow radar, the version for Comanche has half the size and half the weight of the current Apache Longbow system, plus it incorporates low observables and electronic scanning,” Linden remarks. “When you get into the topic of a radar interferometer, because the Apache doesn’t have a low radar signature, it spends a lot of time determining when it is being seen, or ‘painted.’ Comanche would have to be 85-percent closer to the source of the emitter before the enemy knows it is there. Comanche will have some type of interferometer, so the crew will know when the enemy is looking at them, but the enemy may not be getting a signal back yet because Comanche’s radar signature is that low. This is very much a part of the ‘See Without Being Seen,’” Linden explains.
The Comanche also carries a comprehensive ASE suite, state-of-the-art communications and navigation, plus a data link through the improved data modem. “Clearly, it is extremely important to explain that Comanche is the eyes of the ground commander. Comanche can show where the enemy is, how strong his forces are, and after collecting all the information, transmit it back to the ground commander in real time, “ Linden says.
“As to its armed capability, when the Army defined Comanche’s original roles and missions, taking over the light attack role of the Cobra was one mission. Comanche can carry enough weaponry for self-defense and to do the light-attack mission. If Comanche is finding targets, it is clearly logical that it carry weaponry to take care of them.”
Looking at the Comanche program’s progress, the next milestone will be the Defense Acquisition Board review in March. Boeing Sikorsky hopes the board moves the program from its demonstration/validation phase and into the engineering-and-manufacturing-development stage. If all goes well, 13 more Comanches will join the two prototypes now in flight test. Five would join the development program, while eight would head for the Army and begin real-world testing of the Apache Longbow/Comanche team.