Part 9 (1/2)

Today the Hornet is the backbone of U.S. carrier aviation, and will remain that way for at least the next decade. Every CVW is being equipped with three F/A-18 squadrons (each with twelve aircraft), which means that fully half of the aircraft on U.S. carrier decks today are Hornets. There will soon be significant Hornet upgrades, with the introduction of new PGMs, as well as a new version of the cla.s.sic AIM-9 Sidewinder. Even so, there can be little doubt that the F/A-18's short legs, limited weapons load, and design compromises will continue to be a lightning rod for critics. Still, the folks who fly the Hornet love their mounts. Though it's a flying compromise, it's easy to fly, forgiving for new pilots, and capable of many different missions.

EA-6B Prowler: The Electric Beast Looking like a flying metal tadpole, the EA-6B Prowler will probably be the last survivor of a long line of Grumman carrier aircraft that date back to before the Second World War. Its mission is electronic warfare (EW), which explains why the aircraft looks like a flying antenna farm. As many as thirty (or more) antennas are smoothly faired into the fuselage or packed into the ”football” (actually, it looks more like a Brazil nut), a fibergla.s.s radome at the top of the vertical stabilizer. These devices allow the Prowler to throw an invisible veil of protection over the aircraft and s.h.i.+ps of the carrier battle group. They detect, cla.s.sify, and locate enemy radar, electronic data links, and communications, then jam them with precisely crafted and targeted interference. And as an added bonus, since 1986 Prowlers have also been capable of making ”hard kills” using the AGM-88 High-Speed Anti-Radiation Missile (HARM), which homes in on radar transmitters and shreds them with a blast-fragmentation warhead.53 Today, the Prowler is the finest tactical EW aircraft in the world. It's so good that the USAF is quietly retiring its own fleet of EF-111 Raven EW aircraft and employing EA-6Bs in joint (USN/USAF) squadrons. All this is even more impressive when you consider that the thirty-year-old Prowler design has been around for almost half of the six decades that radar has been used in military operations; and with regular updates, it has at least another ten or fifteen years to go.

Electronic warfare (intercepting and jamming enemy signals) began with the first military use of radio in the Russo-j.a.panese War (1905), and reached a high degree of sophistication during the Second World War, as Axis and Allied scientists and technicians fought for control of the electromagnetic spectrum. EW aircraft have been in use since World War II, with modified USN TBF/TBM Avengers being among the first such aircraft. The start of the Vietnam War saw two carrier-capable EW birds in service with the Navy, though both were already getting old. The EA-1E was a modification of the cla.s.sic Douglas AD-1 Skyraider, while the EKA-3B ”Electric Whale” (which also served as a tanker aircraft) was a development of the Cold War-era A-3 Skywarrior attack bomber. As American aircraft began to fall to radar-controlled AAA guns, SAMs, and MiGs over Vietnam, the need for a third-generation EW aircraft became almost desperate. Out of this need came the development of what would become the EA-6 Prowler.

The original airframe of the Prowler was derived from the A-6 Intruder, which was the Navy's first true true all-weather, day or night, low-level medium-strike aircraft. The Intruder saw extensive combat in Vietnam, the Cold War, and Desert Storm, and was immortalized in Stephen c.o.o.nts's 1986 novel, all-weather, day or night, low-level medium-strike aircraft. The Intruder saw extensive combat in Vietnam, the Cold War, and Desert Storm, and was immortalized in Stephen c.o.o.nts's 1986 novel, Flight of the Intruder. Flight of the Intruder. The Prowler's immediate ancestor, the EA-6A, was a modified two-seat ”Electric Intruder” developed to fill a Marine Corps requirement for a jammer aircraft that could escort strike missions into the high-intensity threat of North Vietnam's integrated air defense system. Hard-won experience showed that what was really needed for such missions were more EW operators and jammers aboard the aircraft. From this came the all-new EA-6B Prowler, which is an all-weather, twin-engine aircraft manufactured by Northrop Grumman Aeros.p.a.ce Corporation as a modification of the basic A-6 Intruder airframe. The first flight of the EA-6B was on May 25th, 1968, and it entered operational service in July of 1971. Just a few months later, the Prowler entered combat over Vietnam with VAQ-132, based on aircraft carriers in the Gulf of Tonkin. The Prowler's immediate ancestor, the EA-6A, was a modified two-seat ”Electric Intruder” developed to fill a Marine Corps requirement for a jammer aircraft that could escort strike missions into the high-intensity threat of North Vietnam's integrated air defense system. Hard-won experience showed that what was really needed for such missions were more EW operators and jammers aboard the aircraft. From this came the all-new EA-6B Prowler, which is an all-weather, twin-engine aircraft manufactured by Northrop Grumman Aeros.p.a.ce Corporation as a modification of the basic A-6 Intruder airframe. The first flight of the EA-6B was on May 25th, 1968, and it entered operational service in July of 1971. Just a few months later, the Prowler entered combat over Vietnam with VAQ-132, based on aircraft carriers in the Gulf of Tonkin.

The Prowler is big for a ”tactical” aircraft. The overall length is 59 feet, 10 inches/17.7 meters. It has a wingspan (with the wings unfolded) of 53 feet/15.9 meters, and sits 16 feet, 3 inches/4.9 meters high on the deck. It is also quite heavy, with a maximum gross takeoff weight of 61,000 lb/ 27,450 kg, much of which is fuel. The Prowler has a cruising speed of just over 500 knots/575 mph/920 kph, an unrefueled range of over 1,000 nm/ 1,150 mi/1,840 km, and a service ceiling of 37,600 feet/11,460 meters.

The EA-6B can hardly be called a ”high performance” tactical aircraft. Although it is quite stable in flight and relatively easy to fly, the Prowler is somewhat underpowered. The two non-afterburning Pratt & Whitney J52-P408 turbojet engines lack the kind of thrust available to F-14 or F-18 crews (11,200 lb/5,080 kg of thrust each), which presents the pilot with a number of challenges during every mission (especially on takeoff and landing). Due to the complexity of its systems, the EA-6B is also a relatively high-maintenance aircraft-about one mission in three returns with a ”squawk” or malfunction requiring unscheduled maintenance. On the plus side, the side-by-side twin c.o.c.kpit arrangement gives maximum efficiency, visibility, and comfort for the four-person crew. This is important during long missions, which can last up to six hours with in-flight refueling. The canopies are coated with a microscopically thin (and very expensive) transparent layer of gold leaf, which reflects microwave energy and protects the crew from getting cooked by their own high-energy jammers.

The Prowler's crew includes a pilot and up to three Electronic Countermeasures Officers (ECMOs). The senior officer on board-either the pilot or one of the ECMOs-is normally the mission commander. In fact, a Prowler squadron commander is often an ECMO rather than a pilot. ECMO-1, who mans the position to the pilot's right, handles navigation and communications, while ECMO-2 and -3 (they sit in the rear c.o.c.kpit) manage the offensive and defensive EW systems. Within the squadron, there are normally more crews than aircraft, due to the workload of flying, administration, and mission planning. In a low-threat environment, a crew of three is considered sufficient-with one ECMO remaining behind on the boat to plan the next mission, catch up on paperwork, or perform any of the countless additional duties that Naval aviators must juggle when they are deployed.

The Prowler's EW capabilities depend largely on the ALQ-99 electronic countermeasures system. This is not a single piece of equipment, but a complex and ever-changing mix of computers, jammers, controls and displays, receivers, and transmitters. Some of these components are built into the airframe, while others are packaged in pods. All are externally identical, but each is optimized for specific frequency bands. Up to five such pods can be carried-two under each wing and one under the fuselage. A more typical mission configuration is two or three pods, with the other stations occupied by fuel tanks or AGM-88 HARM missiles. Each pod generates its own electrical power, using a ”ram air turbine” or RAT (a compact generator spun by a small propeller). To generate full power for jamming, the aircraft must fly above a minimum speed (225 knots). Using the RATs brings a slight drag penalty; the Prowler loses about 1 % of its maximum combat radius for each pod carried. Still, the pods and missiles are the reason why the Prowler exists. Without the electronic smoke screen provided by the EA-6B's jamming pods, losses to enemy defensive systems would be many times greater than they have been.

Normally, the EA-6B is used to provide a combination of services for strike packages inbound to a target area. If active SAM sites are nearby, the ECMOs will use the ALQ-99 to provide targeting for the HARMs, which are deadly accurate when fired from a Prowler. Once the HARMs are gone, the EA-6B orbits away from the target area and uses the ALQ-99 jammer pods to ”knock back” enemy radars and other sensors that might engage the strike group. Other missions include electronic surveillance, as the ALQ-99 is a formidable collection system for electronic intelligence (ELINT). Because they are considered ”high value units” by enemy defenders, one or two fighters usually provide them with an escort, just in case the locals get nosey. In fact, no Prowler has ever been lost in combat, though about forty have been destroyed in accidents. The worst of these was a horrific crash while landing aboard the Nimitz Nimitz (CVN-74) back in 1979, which killed the entire crew as well as a number of deck personnel in the ensuing fire. (CVN-74) back in 1979, which killed the entire crew as well as a number of deck personnel in the ensuing fire.

EW is an unusual facet in the spectrum of warfare. For every measure there is a countermeasure, and the useful life span of a system in actual combat is often only a few months. Because a new ”generation” of electronic warfare technology emerges every few years, if you fall a generation behind you are ”out of the game.” This helps to explain the bewildering variety of upgrades and variants that mark the Prowler's long career. Production of new-built Prowlers ended several years ago, but about 125 remain in active service today. This is just enough for twelve Navy, four Marine Corps, and four ”joint” squadrons of EA-6Bs. Normally, each deploys with four aircraft. Navy and joint USAF/USN Prowler squadrons are home-based at NAS Whidbey Island, Was.h.i.+ngton, while the Marine units live at MCAS Cherry Point, North Carolina. The joint EA-6B squadrons are a new phenomenon in the post-Cold War world, an expression of budget realities that no longer allow the services to duplicate aircraft types with the same mission. Although the Navy and USAF developed very different EW concepts and doctrine over the years, the Air Force has agreed to retire its only tactical jammer aircraft, the EF-111 Raven. Now the two services will ”share” five joint ”expeditionary” Prowler squadrons, which will operate with mixed Navy and Air Force ground and flight crews. Despite the predictable concerns about USAF officers commanding Navy squadrons (or vice versa), this program is well under way and looks to be a real winner.

Like their brethren in the Tomcat community, EA-6B crews have learned some new tricks in recent years, like shooting AGM-88 HARM missiles at enemy radars. Prowlers have even been used as command and control aircraft, functioning as strike leaders for other planes on bombing missions. Other improvements include plans to start another upgrade program known as ICAP (Improved Capability) III. This will take the basic EA-6B package as it currently exists (known as Block 89) and add improved computers, signal processors, and jammers, as well as a GPS receiver, new radios and data links, and other new avionic systems. ICAP III-equipped Prowlers should begin to appear in a few years. As for future EW aircraft on carriers, long-range plans have been developed for a two-seat EW version of the new F/A-18E/F Super Hornet. A highly automated follow-on version of ALQ-99 would be fitted to this bird, as well as more advanced HARMs and other systems. However, since there is no money for this bird in the current budget, the old Prowlers will have to soldier on for at least another decade or two.

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A cutaway view of a Raytheon AGM-88 HARM anti-radiation missile.

JACK RYAN ENTERPRISES, LTD., BY LAURA DENINNO.

E-2C Hawkeye: Eyes of the Fleet Put a sensor of sufficient resolution high enough, and you will see enemy forces before they can harm you. This is the guiding princ.i.p.al behind most early warning systems, from reconnaissance satellites to Unmanned Aerial Vehicles (UAVs). For naval leaders, there is no more important ”high ground” than that occupied by Airborne Early Warning (AEW) aircraft. The first U.S. Navy AEW birds date back to World War II, when converted TBF/ TBM Avengers were modified to carry a small airborne radar and operator for the purpose of detecting incoming j.a.panese Kamikaze aircraft far enough out for fighters to be vectored to intercept them. After the war, special purpose-built AEW aircraft were developed. These were designed to deal with the new generation of jets and ASMs faced by Cold War-era Naval forces. The first of these was the Grumman E-1 Tracer, a development of the S-2F Tracker ASW aircraft. For almost a decade the E-1 worked as the primary carrier-based AEW aircraft for the USN; but the operational conditions of the Vietnam conflict showed the numerous shortcomings of the Tracer, including poor overland radar performance and limited endurance and service alt.i.tude. Though they served aboard modified Ess.e.x-cla.s.s Ess.e.x-cla.s.s (SCB-27C/CV-9) carriers until 1976, there was a clear need for a more advanced AEW aircraft for the fleet. That aircraft was the E-2 Hawkeye. (SCB-27C/CV-9) carriers until 1976, there was a clear need for a more advanced AEW aircraft for the fleet. That aircraft was the E-2 Hawkeye.

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The business end of a VRC-40 C-2A Greyhound COD aircraft on the deck of the USS George Was.h.i.+ngton (CVN-73). These aircraft are used to ferry personnel, cargo, and supplies to and from carrier battle groups.

JOHN D. GRESHAM.

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One of the last propeller-driven aircraft in the CVW, the E-2C Hawkeye is the Navy's all-weather, carrier-based tactical AEW aircraft. The E-2C uses computerized sensors for early warning, threat a.n.a.lysis, and control against air and surface targets. It provides the carrier battle group with all-weather AEW services, as well as command, control, and communications (C3) functions for the carrier battle group. Additional missions include surface surveillance, strike and interceptor control, Combat Search and Rescue (CSAR) guidance, Over-the-Horizon (OTH) targeting, and communications relay. Designed to a 1955 specification, and upgraded through at least six generations of electronic technology, the Hawkeye remains in production today. The E-2C has also been adopted by the French Navy, and at least five other countries that do not even have aircraft carriers. This is a tribute to the cost-effective mix of robust airframe, compact sensor and avionics suite, and turboprop power plants. Unit cost: $51 million-cheap for the protection it provides. Before you gag on that number, consider that a new F/A-18E/F Super Hornet will cost you even more per copy, and I don't know any battle group commander who would not like a few more of the precious E-2Cs.

One thing all that money does not buy is beauty. As you walk up to a Hawkeye, pieces of it seem to be going everywhere. Wings are folded back on the fuselage, with the big radar rotodome perched up top like a tethered flying saucer. Though it is not gorgeous to look at, the E-2C has a functional elegance, doing the same kind of mission as its larger USAF cousin, the Boeing E-3 Sentry. That it does this on an airframe a fifth the size, and off a carrier deck, is a measure of its sophistication and value. When the Grumman engineers designed the E-2, they started with a perfect cylinder. Into this they packed all the electronics, fuel, two pilots, and three radar controllers. The finis.h.i.+ng touch came when they mounted the rotating radar dome (called a ”rotodome”) on top, and attached a pair of long wings mounting a pair of Allison T-56-A427 turboprop engines with five thousand shaft horsepower each.

Dimensionally, the Hawkeye is 57 feet, 6 inches/17.5 meters long, with a wingspan of 80 feet, 7 inches/28 meters, and a height of 18 feet, 3 inches/ 5.6 meters to the top of the radar dome. Though it is the largest aircraft flying on and off carriers today, it is not the heaviest. At a maximum gross takeoff weight of 53,000 lb/23,850 kg (40,200 lb/18,090 kg ”dry”), the E-2C is actually lighter than the F-14 Tomcat. The wings have the longest wingspan of any carrier aircraft in the world; and when folded, they use the cla.s.sic Grumman ”Stow-Wing” concept, which has them folding against the fuselage. The tail is composed of a horizontal stabilizer with four vertical stabilizers to give the Hawkeye the necessary ”bite” to move the heavy bird around the sky. Though it has only ten thousand horsepower behind the twin props, the Hawkeye is capable of speeds over 300 knots/345 mph/552 kph, and can operate at alt.i.tudes of 30,000 feet/9,144 meters. Because Hawkeyes are unarmed, no battle group commander would be considered sane if there were less than two fighters protecting his E-2C. Hawkeyes are true ”high value units” and are always always a target for enemy fighters. a target for enemy fighters.

On board, the crew of five is busy, for they're doing a job that on the larger E-3 Sentry takes several dozen personnel. The pilot and copilot fly precisely positioned and timed racetrack-shaped patterns, designed to optimize the performance of the E-2C's sensors. In back, the three radar-systems operators are tasked with tracking and sorting the contacts detected by the Hawkeye's APS-145 radar. This Westinghouse-built system is optimized for operations over water and can detect both aircraft and surface contacts out to a range of up to 300 nm/345 mi/552 km. To off-load as much of the workload as possible, a great deal of the raw data is sent back to the task force's s.h.i.+ps via a digital data link. With this off-board support, the three console operators are able to control a number of duties, including intercepts, strike and tanker operations, air traffic control, search and rescue missions, and even surface surveillance and OTH targeting.

Along with the 141 E-2Cs produced for the USN, the Hawkeye has had considerable export success. No less than six foreign governments have bought them: Israel (four), Egypt (six), France (two for their new carrier Charles de Gaulle), Charles de Gaulle), j.a.pan (thirteen), Singapore (four), and Taiwan (four). There are more Hawkeyes in use throughout the world than any other AEW aircraft ever built. j.a.pan (thirteen), Singapore (four), and Taiwan (four). There are more Hawkeyes in use throughout the world than any other AEW aircraft ever built.

There also has been one major variant of the Hawkeye, a transport version known as the C-2A Greyhound. Basically an E-2 airframe with a broader fuselage and the radar rotodome deleted, it can deliver cargo and pa.s.sengers hundreds of miles/kilometers out to sea. Known as a COD (for Carrier Onboard Delivery) aircraft, it replaced the elderly C-1 Trader, which is itself a variant of the earlier E-1 Tracker. With its broad rear loading ramp and fuselage, the C-2 can carry up to twenty-eight pa.s.sengers, twenty stretcher cases, or cargo up to the size of an F-110 engine for the F-14.

The Hawkeye has had a long run in USN service. The original -A model was first flown in October 1960, to provide early warning services for the new generation of supercarriers then coming into service. In January 1964, the first of fifty-nine E-2As were delivered to their squadrons, and were shortly headed into combat in Southeast Asia. These were later updated to the E-2B standard, which remained in use until replaced by the E-2C in the 1970's. The first E-2Cs entered USN service with Airborne Early Warning Squadron (VAW) 123 at NAS Norfolk, Virginia, in November of 1973. The -C-model Hawkeye was produced in order to provide the F-14 Tomcat with an AEW platform matched to the new fighter's capabilities. Though visually identical to the earlier models, the E-2C was equipped with new-technology digital computers that provided a greatly increased capability for the new Hawkeye. These gave the operators the ability to track and intercept the dozens of Soviet bombers and hundreds of ASMs and SSMs that were expected to be fired at CVBGs if the Cold War ever turned ”hot.”

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E-2C Hawkeye AEW aircraft on the deck of the USS George Was.h.i.+ngton George Was.h.i.+ngton (CVN-73). They generally parked alongside the island structure, on a spot called ”the Hummer Hole.” (CVN-73). They generally parked alongside the island structure, on a spot called ”the Hummer Hole.”

JOHN D. GRESHAM.

In any event, the E-2Cs never directed the ma.s.sive air battles they had been designed for. Instead, the Hawkeye crews spent the declining years of the Cold War flying their racetrack patterns over the fleets, maintaining their lonely vigil for a threat that never came. Carrier-based Hawkeyes were not strangers to combat, however. E-2Cs guided F-14 Tomcat fighters flying combat air patrols during the 1981 and 1989 air-to-air encounters with the Libyan Air Force, as well as the joint USN/USAF strike against terrorist-related Libyan targets in 1986. Israeli E-2Cs provided AEW support during their strikes into Lebanon in 1982, and again during the larger invasion the following year. More recently, E-2Cs provided the command and control for successful operations during the Persian Gulf War, directing both land strike and CAP missions over Iraq and providing control for the shoot-down of the two Iraqi F-7/MiG-21 fighters by carrier-based F/A-18's. E-2 aircraft have also worked extremely effectively with U.S. law enforcement agencies in drug interdictions.

Today the entire Hawkeye fleet is being upgraded under what is called the Group II program. Along with thirty-six new-production aircraft, the entire USN E-2C fleet is being given the improved APS-145 radar, new computers, avionics, data links, and a GPS/INS system to improve flight path and targeting accuracy. This means that a single Hawkeye can now track up to two thousand targets at once in a volume of six million cubic miles of airs.p.a.ce and 150,000 square miles of territory. Current plans have the Hawkeye/ Greyhound fleet serving until at least the year 2020, when a new airframe known as the Common Support Aircraft (CSA) will be built in an AEW version. By that time, the basic E-2 airframe will have served for almost six decades!

A VS-32 S-3B Viking ASW aircraft on the deck of the USS George Was.h.i.+ngton Was.h.i.+ngton (CVN-73) with wings folded. The S-3B has rapidly taken over many critical roles in carrier operations, espcially in-flight refueling of other aircraft. (CVN-73) with wings folded. The S-3B has rapidly taken over many critical roles in carrier operations, espcially in-flight refueling of other aircraft.

JOHN D. GRESHAM.

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Lockheed Martin S-3B Viking: The Vital ”Hoover”

Antisubmarine warfare (ASW) is probably the most complex, frustrating, operationally challenging, and technically secretive mission that any aircraft can be called upon to perform. To locate, track, cla.s.sify, and destroy a target as elusive as a nuclear submarine in the open ocean often seems virtually impossible. And against a quiet modern diesel boat in noisy coastal waters, the odds are even worse. In fact, the ASW mission doesn't have to be that successful. It has succeeded as long as enemy subs are forced to go deep, run quiet, and keep their distance from a Naval task force or convoy. It is a matter of record that the most effective weapon against submarines during the Second World War was the ASW patrol aircraft. Such aircraft have continued to do this job ever since.

Today, the USN operates two fixed-wing ASW aircraft. One is the venerable four engined P-3C Orion, which operates from land bases. The other is its ”little brother” from the Lockheed Martin stable, the S-3B Viking, which is carrier-capable. Airborne ASW has long been a Lockheed specialty. Their land-based Hudson and Ventura patrol bombers played a key role in World War II against German U-boats. More recently, their P-2V Neptune and P-3 Orions have kept vigil over the world's oceans, watching for everything from submarines to drug-running speedboats. The so-called ”sea control” mission is thankless work, with nearly day-long missions, most of which are flown over inhospitable and empty seas. The boredom arising from these missions in no way reduces their importance. A maritime nation that cannot monitor and control the sea-lanes it uses is destined to sail at the whims of other powers.

Early on, carrier aviators knew that they too needed the services of such aircraft, and began to build specially configured ASW/patrol aircraft shortly after the end of World War II. The first modern carrier-based ASW aircraft was Grumman's twin-engine S-2 Tracker, which entered service in 1954 and remained in the fleet for over twenty-five years with more than six hundred built.54 In 1967, the growing sophistication of the Soviet submarine threat led the Navy to launch a compet.i.tion for a radically new generation of carrier ASW aircraft. Known as the VSX program, it was designed both to replace the Tracker and to provide a utility airframe for other applications. In 1969, the design submitted by Lockheed and Vought was declared the winner and designated S-3. The prototype S-3A first flew on January 21 st, 1971, and the type entered service in 1974 with VS-41 at NAS North Island, California. By the time S-3A production ended in 1978, 179 had been delivered. In 1967, the growing sophistication of the Soviet submarine threat led the Navy to launch a compet.i.tion for a radically new generation of carrier ASW aircraft. Known as the VSX program, it was designed both to replace the Tracker and to provide a utility airframe for other applications. In 1969, the design submitted by Lockheed and Vought was declared the winner and designated S-3. The prototype S-3A first flew on January 21 st, 1971, and the type entered service in 1974 with VS-41 at NAS North Island, California. By the time S-3A production ended in 1978, 179 had been delivered.

The S-3 Viking is a compact aircraft, with prominent engine pods for its twin TF-34-GE-2 engines. This is the same basic non-afterburning turbofan used on the Air Force's A-10 ”Warthog,” and its relatively quiet ”vacuum-cleaner” sound gives the Viking its nickname: the ”Hoover.” The crew of four sits on individual ejection seats, with the pilot and copilot in front, and the tactical coordinator (TACCO) and sensor operator (SENSO) in back. A retractable aerial refueling probe is fitted in the top of the fuselage, and all S-3B aircraft are capable of carrying an in-flight refueling ”buddy” store. This allows the transfer of fuel from the Viking aircraft to other Naval aircraft. Because ASW is a time-consuming business that requires a lot of patience and equipment, the Viking is relatively slow, with a long range and loiter time. This means the S-3 is pretty much a ”truck” for the array of sensors, computers, weapons, and other gear necessary to find and hunt submarines. But don't think that the Viking is a sitting duck for anyone with a gun or AAM. The S-3 is surprisingly nimble, and it's able to survive even in areas where AAW threats exist.

There are three primary ways to find a submarine that does not want to be found. You can listen for sounds, you can find it magnetically (something like the way compa.s.s needles find north), or you can locate a surfaced sub with radar. Since sound waves can travel a long way underwater, a sub's most important ”signature” is acoustic. But how can an aircraft noisily zooming through the sky listen for a submarine gliding beneath the waves? The answer, developed during World War II, is the son.o.buoy. This is an expendable float with a battery-powered radio and a super-sensitive microphone. ”Pa.s.sive” son.o.buoys simply listen. ”Active” son.o.buoys add a noise-makerthat sends out sound waves in hope of creating an echo. By dropping a pattern of son.o.buoys and monitoring them, an ASW aircraft can spread a wide net to catch the faint sounds of the sub's machinery, or even the terrifying ”transient” of a torpedo or missile launch.

Another detectable submarine signature is magnetism. Since most submarines are made of steel, they create a tiny distortion of the earth's magnetic field as they move.55 The distortion is The distortion is very very small, but it is detectable. A ”magnetic anomaly detector” (MAD) can sense this signature, but it is so weak that the aircraft must practically fly directly over the sub at low alt.i.tude to do so. small, but it is detectable. A ”magnetic anomaly detector” (MAD) can sense this signature, but it is so weak that the aircraft must practically fly directly over the sub at low alt.i.tude to do so.56 In order to isolate the MAD from the plane's own electromagnetic field, it is mounted on the end of a long, retractable ”stinger” at the tail of the aircraft. In order to isolate the MAD from the plane's own electromagnetic field, it is mounted on the end of a long, retractable ”stinger” at the tail of the aircraft.

Eventually, every submarine must come to periscope depth to communicate, snorkel, or just take a quick look around. Although periscope, snorkel, and communications masts are usually treated with radar-absorbing material, at close range sufficiently powerful and sensitive radar may obtain a fleeting detection. Finally, there are more conventional means of detection. For example, an airborne receiver and direction finder may pick up a sub's radio signals, if it is foolish or unlucky enough to transmit when an enemy is listening. And sometimes the telltale ”feather” from a mast can be seen visually or through an FLIR system.

The integrated ASW package of the initial version of the Viking, the S-3A, was designed to exploit all of these possible detection signatures. Sixty launch tubes for son.o.buoys are located in the underside of the rear fuselage. In addition, the designers provided the ASQ-81 MAD system, an APS-116 surface search radar, a FLIR system, a pa.s.sive ALR-47 ESM system to detect enemy radars, and the computer systems that tie all of these together. Once a submarine has been found, it is essential that all efforts be made to kill it. To this end, the S-3 was not designed to be just be a hunter; it was also a killer. An internal weapons bay can accommodate up to four Mk. 46 torpedoes or a variety of bombs, depth charges, and mines. Two wing pylons can also be fitted to carry additional weapons, rocket pods, flare launchers, auxiliary fuel tanks, or a refueling ”buddy store.”

All this made the S-3A one of the best sub-hunting aircraft in the world, which was good enough in its first decade of service. By 1981, though, the -A model Viking clearly needed improvement in light of the growth in numbers and capabilities of the Soviet submarine fleet. In particular, the improved quieting of the Russian boats made hunting even more of a challenge. In order to improve the S-3's avionics, son.o.buoy, ESM and radar data processing, and weapons, a conversion program was started. The result was the S-3B, which upgraded basic -A model airframes to the new standard. The first S-3Bs began to arrive in the fleet in 1987, and they quickly showed both their new sea control abilities and capability to fire AGM-84 Harpoon antis.h.i.+p missiles. This is the version that serves today.

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The prototype ES-3A Shadow on a test flight. The sixteen Shadows provided the fleet with electronic reconnaissance and surveillance services until recently.

JOHN D. GRESHAM.

One of the original hopes for the S-3 was to provide a basic airframe for a number of other aircraft types. Unfortunately, the small production run of the Viking has limited its opportunities for other roles. A small number of early S-3As were modified by removing all the ASW equipment and fittings for armament, allowing them to carry urgent cargo and mail and providing seats for a crew of three and up to six pa.s.sengers (with minimal comfort). Designated US-3A and possessing a much longer range than the normal C-2A Greyhound COD aircraft, a total of five served in the Pacific fleet until they were recently retired. A dedicated tanker version, the KS-3A, was tested in 1980, but never went into production.

The single most important variant was the ES-3A ”Shadow,” an electronic surveillance (ESM) and signals intelligence (SIGINT) platform, which replaced the venerable EKA-3B ”Electric Whale.” Externally, the Shadow is quite distinctive, with a prominent dorsal hump and a retractable radome. About 3,000 lb/1,360 kg of ASW gear was removed and 6,000 lb/2,721 kg of electronics were packed into the weapons bay. While the Shadow is unarmed, it can also carry external fuel tanks and ”buddy” refueling stores. Sixteen of these aircraft are split between two squadrons: VQ-5 (the ”Sea Shadows”) in the Pacific Fleet and VQ-6 (the ”Ravens”) in the Atlantic. Detachments of two or three aircraft normally deploy with every carrier air group, providing ESM, SIGINT, and OTH support for the CVBG. Unfortunately, recent budget cuts have targeted the shadow community which appears to be headed for disestablishment. Plan on seeing the ES-3 head for the boneyard in 1999.

The S-3 community has changed a great deal since the end of the Cold War. As long as the Soviet Union maintained the world's largest submarine fleet, the ASW squadron was an integral part of the carrier air group. But today, that ”blue-water” submarine threat has receded. This hardly means that the S-3's can be retired and their crews given pink slips. On the contrary, the VS squadrons have taken on a whole new set of roles and missions, making them more valuable than ever. After the premature retirement of the KA-6D fleet in 1993, they took on still another role, becoming the primary aerial refueling tanker for the CVW. This has not proved to be the best solution to the aerial refueling problem, since an S-3B can only off-load about 8,000 lb/3,628 kg of fuel, as compared to over 24,000 lb/10,886 kg for the KA-6D. With the thirsty F/A-18's needing at least 4,000 lb/1,814 kg every time they go on a long CAP or strike mission, even the ES-3 Shadows are being used as tankers! To reflect all this, the previous ASW designation of their squadrons has been changed to ”Sea Control,” which uses the ”VS” nomenclature.