Meanwhile, it was time to replace the SH-3, the protectors of the “inner zone” of ASW defenses for the CVBG. Once the SH-60Bs had been well launched, it was a logical jump to build a Sea King replacement from the existing Seahawk airframe. In 1985 the USN contracted with Sikorsky for development and production of seventy-four “CV-Helo” versions of the H-60. They would be equipped with a new lightweight dipping sonar and some avionics improvements over the earlier-B-model Seahawks. These improvements came at a price, however: the loss of most of the LAMPS equipment, including the sonobuoy launchers and data links. The new SH-60F came into service in 1989, and began to replace the elderly SH-3’s aboard the carriers. At this same time, in response to- an ongoing initiative to expand the special warfare capabilities of the USN, another H-60 variant went into development. The HH-60H version of the Seahawk provided a whole new range of capabilities for battle groups commanders, including Combat Search and Rescue (CSAR) and the covert insertion and retrieval of Special Forces like the famous Sea-Air-Land (SEAL) teams.
An HH-60G special operations/SAR helicopter landing on the deck of the USS George Washington (CVN-73).
JOHN D. GRESHAM
Having three aircraft all based upon the same H-60 airframe has saved lots of scarce naval aviation dollars. All share the same 1,690-horsepower General Electric T700 turboshaft engines, as well as a common rotor system (with a diameter of 53 feet, 8 inches/16.4 meters) and transmission. In fact, the primary differences between the -B, -F, and -H versions are in the various mission-equipment packages. With an overall length of 64 feet, 10 inches/ 19.75 meters, height of 17 feet/5.2 meters, and maximum gross weight of 21, 884 lb/9,908 kg, the Seahawk is a compact and nimble aircraft. It handles well on wet, rolling decks, even those of small escort ships. To assist ships’ crews in handling, Seahawks have a cable system called RAST (Recovery, Assist, Secure, and Traversing), allowing ships’ crews to haul it down safely in heavy seas. Developed from the Canadian “Beartrap” system, RAST has a tracked receiver on the helicopter platform, which “captures” a small cable hanging from the bottom of the helicopter. Once the receiver has snagged the cable, the helicopter is hauled down, and then towed into the ship’s hangar.
The armament of the Seahawks, while limited, is well tailored for their assigned missions. The normal weapons load for the ASW versions is a pair of Mk. 46 or Mk. 50 lightweight torpedoes. Extra fuel tanks can also be carried to extend the Seahawk’s range. The -B model is also equipped to fire the Norwegian-built AGM-119 Penguin Mk. 2 Mod. 7 ASM. With a range of up to 18 nm/33 km and a passive infrared seeker, it can take out a patrol boat or small escort ship, even in close proximity to a shoreline or neutral shipping traffic. All the variants of the Seahawk can be fitted with light machine guns, and have rescue hoists for hauling in downed air crews or other personnel.
The various models of Seahawk have helped maintain the sometimes-dicey peace in the post-Cold War world. In the Persian Gulf, for instance, LAMPS III birds have been monitoring maritime traffic and the maritime embargo of military materials into Iraq. At the same time, the -F models have kept a wary eye on the three Project 877/Kilo-class diesel boats of the Iranian Navy, and -H model Seahawks have been transporting inspection teams to ships and conducting CSAR missions. Seahawks have been active in supporting our operations in Bosnia as well. In fact, you probably could not even operate a modern USN task force without Seahawks. This is emphasized by the continuing popularity of the H-60 to export customers around the world. So far, Spain, Japan, Australia, and Taiwan have all bought their own versions of the Seahawk to operate off various classes of escort.
A cutaway view of a Raytheon BGM-109 Tomahawk Land Attack Missile.
JACK RYAN ENTERPRISES, LTD., BY LAURA DENINNO
The future of the Seahawk community is looking decidedly upbeat these days, mostly due to the modernization plan that has recently been announced. Shortly, the two hundred or so surviving -B, -F, and -H-model Seahawks will be sent back to the Sikorsky factory in Stratford, Connecticut, to be remanufactured to a common SH-60R standard. All Seahawks will now carry the LAMPS III and -F sensor packages (both sonobuoys and dipping sonar), as well as improved engines and avionics. This upgrade should make it possible for the -R Seahawks to last into the 21 st century until the next generation of sea control helicopter is designed.
Unfortunately, the use of the HH-60H airframes to produce -R-model birds will create a shortfall for the CSAR/special operations force. At the same time, the elderly fleet of UH-46 Sea Knight Vertical Replenishment (VERTREP) helicopters is about to fall out of the sky from wear and tear. Recognizing this, the Navy has ordered the development and production of an entirely new model of Seahawk, the CH-60, which will take over the CSAR/special operations duties previously assigned to the -H model, as well as the VERTREP mission of the Sea Knight. The first prototype is currently flying, and low-rate production has been approved for up to two hundred of the CH-60 variants. First deliveries to the fleet will begin in FY-1999.
Raytheon BGM-109 Tomahawk: The “Other” Strike Aircraft
Not all the aircraft that fly from the CVBG are manned. Another strike weapon available to battle group commanders for hitting targets ashore is the BGM-109 Tomahawk cruise missile. The Tomahawk is an all-weather submarine- or ship-launched land-attack cruise missile, with a variety of warheads. Stowed in vertical launch tubes or containers, it can be launched from long range, and can strike with pinpoint precision (less than three meters/ten feet from the aimpoint). In the U.S. Fleet, everyone calls it the TLAM (pronounced “tea-lamb”), which is an acronym for Tomahawk Land Attack Missile, to distinguish it from the discontinued TASM, or Tomahawk Anti-Ship Missile. Conceived in the 1970’s for a nuclear “Doomsday” scenario, TLAM has been reborn in the ’90’s as the big stick of U.S. policy.
TLAM looks rather like a cigar with stubby pop-out wings and tail fins. A solid-fuel booster rocket (which is attached to the rear of the missile and looks like an oversized coffee can) hurls the missile out of its launch canister/ container. TLAM is 18 feet, 3 inches/5.6 meters long (20 feet, 6 inches/6.25 meters with the booster), 20.4 inches/51.8 cm in diameter (it fits inside a standard 21-in/533mm torpedo tube), has a deployed wingspan of 8 feet, 9 inches/2.7 meters, and weighs 2,650 lb/1,192.5 kg (3,200 1b/1,440 kg with the booster). It flies at a speed of approximately Mach .75/550 kn/880 kph, and has a range of 870 nm/1,000 mi/1,610 km for the basic land-attack version. The standard payload for a TLAM is a 1,000-lb/454-kg-class “unitary” warhead that has blast, fragmentary, and penetration effects. There are also versions with other types of warheads, including small submunitions for use on area targets like SAM sites and airfields. TLAMs are not as stealthy as F-117’s or B-2’s, but they are still almost undetectable by an enemy, thanks to the missile’s small radar cross-section and low-altitude flight path.59 And because the turbofan engine emits very little heat energy, infrared detection is no easier.
The current TLAM inventory has a complex family tree of variants and modifications, extending through three distinct generations or “Blocks.” These are distinguished mainly by the different guidance and warhead systems shown in the table below:
BGM-109 Tomahawk Variant Chart
The launch of a BGM-109 Tomahawk Land Attack Missile (TLAM) from the Aegis cruiser USS Shiloh (CG-67) during Operation Desert Strike in 1996. Cruise missiles like the Tomahawk are frequently integrated with manned airstrikes to help suppress enemy air defenses.
OFFICIAL U.S. NAVYPHOTO
The nuclear-armed TLAM-N was taken out of service by a Presidential executive order shortly after the end of the Cold War in 1991. Similarly, the collapse of the Soviet Fleet at the end of that conflict meant that the long-range (greater than 300 nm/555 km) antishipping capabilities of the TASM were no longer required. Following their withdrawal from service, the TLAM-N and TASM airframes were remanufactured into new Block III missiles (the Navy often does this with so-called “legacy” systems). The Block III missiles have been recen
tly given the new BDU-36B penetrating warhead, with a case composed of highly reactive titanium for penetrating a good thickness of reinforced concrete, as well as exceptional incendiary effects. In about a hundred of the Block IIIs, there is also a one-way satellite data link that at various times during the flight sends updates on the missile’s status and position back to the firing units and command centers. The Block III’s precision navigational systems use a combination of guidance modes to give them the same kind of accuracy (less than three meters/ten feet from the aim point) as an LGB.
When a Tomahawk is launched, the Mk. 111 rocket booster fires, thrusting it vertically into the air (after burnout, the booster is discarded). The wings and guidance fins are then deployed and a cover plate is blown off the inlet duct of the tiny Williams International F107-WR-402 turbofan engine. The F107 burns a special high-energy, high-density liquid fuel called JP-8, which gives it more range per gallon than normal JP-5. As soon as the missile has stabilized, it begins to fly a preprogrammed route to its first navigational waypoint just prior to landfall. Once over land, the missile flies along its programmed flight path to the target. Most of the time, the flight path is monitored by an inertial guidance system, which senses the drift from winds and small flight errors. In order to compensate for any “drift” in the inertial system itself, the TLAM utilizes a system called Terrain Contour Mapping (TERCOM) to match the terrain below with data from pre-surveyed strips of land stored in the missile’s computer. Should the flight path deviate from the planned course, it will be corrected, and the missile will continue to the next TERCOM strip.60
When the missile reaches the target area, the precision Digital Scene Matching Area Correlation (DSMAC) system takes control. This utilizes a downward-looking infrared camera with an infrared illumination system (for consistent lighting at night) that matches up features on the ground and makes any necessary corrections to the missile’s flight path. Though the DSMAC system does not actually “home” onto the target, it does provide enough accuracy to fly a TLAM through the goalpost uprights on a football field. In order to improve the existing Inertial/TERCOM/DSMAC guidance package, a GPS receiver has been installed in the new Block III missiles. In the event of a rapidly planned strike, GPS eliminates the need for TERCOM maps; and with GPS, the atomic clocks aboard the satellites provide a precision Time-of-Arrival (TOA) control capability. Using this, the missile’s arrival at the target can be timed to the second. Once the TLAM is over the target area, the missile’s job is to put the payload onto the desired target. It can fly or dive into the impact point (a bunker or building), explode over a “soft” target (such as an aircraft or radar), or spread a load of submunitions over a desired area.
While the existing stockpile of Block II and III TLAMs are capable of doing a fine job, there are plans to make them even better. Admiral Johnson would like to drive the cost of TLAM strike missiles down, and the way to manufacture them more cheaply is to re-engineer the design to take advantage of new structures, materials, and computer/software advances. This proposed TLAM variant is the so-called “Tactical Tomahawk,” which would probably cost around $575,000 a copy. Tactical Tomahawk would be equipped with a two-way satellite data link, which would allow it to be re-targeted in flight. The new TLAM will also be equipped with a camera system, allowing the missiles to conduct their own damage assessments. Expect to see this new variant in the a few years.
One of the prototype/preproduction F/A-18 Super Hornets during a test flight. The Super Hornet will replace early-model F-14 Tomcats in the early 21st century.
BOEING MILITARY SYSTEMS
Once upon a time, the TLAM filled naval aviators with anxieties. They feared that the Tomahawk had “This machine wants your job!” written on the side. But their fears have faded, and today most of them view the TLAM the way a hunter sees his favorite hunting dog—good and faithful beasts that are willing to go places where human beings should not go, and do things that human beings really should not do. Still, naval aviators like to joke that in the next war no more Navy Crosses will be handed out; the cruise missiles will have hit the really difficult targets! Every bomb carries a political message. Today, TLAM is probably America’s most effective bomb-carrying political messenger. The “Gunboat Diplomacy” of the 19th century has become “Tomahawk Diplomacy” in the 20th and 21st.
The Future: Boeing F/A-18E/F Super Hornet
The shortcomings of the existing F/A-18 Hornet are well understood, and have long caused Naval aviators to wish for their resolution. Meanwhile, the 1993 retirement of the A-6E/KA-6D fleet and the failure to produce a replacement for it have meant that NAVAIR has been hard pressed to get any kind of new aircraft onto U.S. carrier decks. At one point the feeling seemed to be that since the Navy was unable to produce new aircraft, perhaps it might be able to field a highly modified one. Back in 1991, the Navy leadership decided to build an upgraded version of the Hornet, which would replace the F-14 and early versions of the F/A-18. This redesigned F/A-18 would (hopefully!) resolve the Hornet’s fuel-fraction problem as well as other shortcomings and provide an interim aircraft until a more advanced and suitable long-term solution to the Navy’s aircraft procurement need could be developed. Thus was born the F/A-18E/F Super Hornet, the key to the Navy’s current naval aviation upgrade plan.
As planned, the F/A-18E (single seat) and -F (two-seat trainer) are more than just -C/D models with minor improvements. They are in fact brand-new airframes, with less than 30% commonality with the older Hornets. The airframe itself has been enlarged to accommodate the internal fuel load that was lacking in the earlier F/A-18’s. With a fuel fraction of around .3 (as opposed to the .23 of the earlier Hornets), much of the range/endurance problems of the earlier birds should be resolved. The twin engines are new General Electric F414-GE-400’s, which will each now deliver 22,000 lb/9,979 kg of thrust in afterburner. There is also a new wing, with enough room for an extra weapons pylon inboard of the wing fold line on each side, which should help resolve some of the complaints about the Hornet’s weapons load. To ensure that the Super Hornet can land safely with a heavier fuel/weapons load than earlier F/A-18’s, the airframe structure and landing gear have also been strengthened. Since most of the-E/F’s weapons load is planned to be expensive PGMs, which must be brought back if not expended, this is essential.
The Super Hornet will also be the first USN aircraft to make use of radar and infrared signature-reduction technologies. Most of the work in this area can be seen in the modified engine inlets, which have been squared off to reduce their signature and coated with radar-absorbing material. This should greatly increase the survivability and penetration capabilities of the new bird.
Finally, the Super Hornet will be the first naval aircraft to carry a new generation of electronic-countermeasures gear including the ALE-50, a towed decoy system that is proving highly effective in tests against the newest threats in the arsenals of our potential enemies.
To back up the new airframe and engines, the avionics of the new Hornet will be among the best in the world. The radar will be the same APG- 73 fitted to the late-production models of the F/A-18C/D. An even newer radar, based on the same fixed-phased-array technology as the APG-77 on the USAF’s F-22A Raptor, is under development as well. To replace the sometimes troublesome Nighthawk pod, Hughes has recently been selected to develop a third-generation FLIR/targeting system for the Super Hornet, which will give it the best targeting resolution of any strike aircraft in the world.
The cockpit, designed again by the incomparable Eugene Adam and his team, will have a mix of “glass” MFDs (in full color!), and an improved user interface for the pilot. One part of this will be a helmet-mounted sighting system for use with the new AIM-9X version of the Sidewinder AAM. Other weapons will include the current array of iron ordnance and PGMs, as well as the new GBU-29/30/31/32 JDAMS, AGM-154 JSOW, and AGM-84E SLAM-ER cruise missile.
There will also be provisions for the Super Hornet to carry larger external drop tanks as w
ell as the same “buddy” refueling store used by the S-3/ES-3 to tank other aircraft.
All this capability comes at a cost, though. At a maximum gross weight of some 66,000 lb/29,937 kg, the Super Hornet will weigh more than any other aircraft on a flight deck, including the F-14 Tomcat.
When McDonnell Douglas (now part of Boeing Military Aircraft) was given the contract to develop the Super Hornet, they set out to have a high level of commonality with the existing F/A-18 fleet. Early on in the design process, though, it became apparent that only a small percentage of the parts and systems could be carried over to the new bird. Despite this lack of true commonality, the Super Hornet was the only new tactical aircraft in the Navy pipeline, and so the Navy went forward with its development.
Today, the aircraft is well into its test program, with low-rate production approved by Congress.61 At around $58 million a copy (when full production is reached), the Super Hornet will hardly be a bargain ( -C/-D-model Hornets cost about half that). On the other hand, when stacked next to the estimated $158-million-dollar-per-unit cost of the USAF’s new F-22A Raptor stealth fighter, the Super Hornet looks like quite a deal! Considering the current budget problems within the Department of Defense, there is a real possibility that one program or the other might be canceled. Since the Super Hornet is already in production (the F-22A has just begun flight tests), it may have an edge in the funding battles ahead.