Carrier: A Guided Tour of an Aircraft Carrier
The origins of the Hornet program date back to the mid-1970’s, when the Navy was beginning to suffer “sticker shock” from the costs of buying new aircraft for its carrier force. The double-digit inflation of the early 1970’s was driving the price of new combat aircraft up at a dangerous rate, bringing about a reassessment of the kinds and numbers of aircraft the U.S. military could afford. After a start was made on the modernization of the F-14, A-6, and S-3, the Navy looked to the problem of replacing the existing force of A-7 light-attack bombers. Since every CVW had two squadrons each of the A-7’s (with a dozen aircraft per squadron), this represented a huge aircraft buy. At the same time, the Navy and Marines had to replace about a dozen squadrons of elderly F-4 Phantom fighters, which operated from carriers and bases. From these twin needs came what was known as the VFAX (Navy Fighter/Attack, Experimental) requirement. The hope was that a single aircraft might be designed to fulfill both the fighter and light-strike roles, and thus save money by reducing the number of airframes. About the same time, the USAF was evaluating a pair of “lightweight” fighter designs, and was preparing to procure one of them. Since the USAF was going to use this aircraft as a multi-role fighter-bomber, the Congress and Department of Defense directed that the Navy and Marines should use a version of the same aircraft. That is where the troubles began.
The two competing lightweight fighter designs, the General Dynamics (GD, now part of Lockheed Martin) YF-16 and the Northrop (also now part of Lockheed Martin) YF-17, had a “fly-off” competition at Edwards AFB in California. When it was over, the YF-16 was declared the winner, and has proved to be an outstanding combat aircraft. The USAF and our allies have bought thousands of the little fighters, and continue to do so to this day. Unfortunately, many of the qualities that made the USAF love the F-16 were unacceptable in a carrier-based aircraft. For example, the Navy prefers twin-engined aircraft for their redundancy and ability to accept battle damage. The F-16 has only a single engine, and is too lightly built to carry some of the equipment needed for carrier operations. Since the Navy had been directed to base the VFAX aircraft on the contenders from the USAF lightweight-fighter competition, it chose to run a “paper” competition that would allow it to evaluate and choose the airplane it would buy.
Meanwhile, both GD and Northrop decided that since neither had recent experience building carrier aircraft, they would look for a partnership with an aircraft company that did. Thus GD in Fort Worth teamed up with its crosstown neighbor Vought, while Northrop adopted McDonnell Douglas (MDC) in St. Louis as its partner. At the end of the evaluation process, the Navy chose a derivative of the twin-engined, twin-tailed YF-17, which it judged was better suited to the rigors of duty aboard aircraft carriers. This award to MDC/Northrop provoked a loud protest from the losing Vought/ GD team, which had thought the original DoD/Congressional direction was an ironclad guarantee that they would win. Though it took an inspired campaign of political pressure and technical documentation by the Navy to preserve the decision, the MDC/Northrop team held on to their win. But there is more to the story.
Winning a contract is one thing. Building the aircraft specified is another thing entirely; especially when it is the most advanced of its type ever built. The Navy and Marine Corps were asking a great deal more from the new aircraft than the USAF was of the F-16, and that complicated matters greatly. For instance, the new bird, now designated the F/A-18 Hornet (the F/A stood for Fighter/Attack), would have to carry a great deal more equipment than the USAF bird. This included a multi-mode radar capable of providing guidance for the large AIM-7 Sparrow AAMs and FLIR targeting pods it was to be equipped with. The Hornet would also have to lug around a lot of extra weight in the form of beefed-up structure (representing about 4,000 lb/1,818.2 kg, approximately 20% of the Hornet’s total weight), to allow it to operate on and off carriers. These requirements proved to be far beyond the modest abilities of the YF-17. The Navy was in fact asking not simply for a Navy version of the original Northrop design, but for a brand-new aircraft. Simply scaling up the YF-17 was not going to do.
To further compound the difficulties presented by this design, there was no true prototype of the F/A-18. The first Hornets to fly were preproduction aircraft, which went directly into operational testing at NAS Patuxent River, Maryland. This meant that any normal problems that might have shown up (and been eliminated) in a prototype were now found in the preproduction birds. This proved to be a costly mistake. In fact, some problems (such as structural cracks) did not show up until the Hornet was actually into squadron service with the fleet. There were also troubles with the aerodynamics around the “cobra hood” and leading-edge extensions, which had to be modified fairly late in the development process. Luckily, the ability of the F/A-18’s new digital fly-by-wire (FBW—the first ever on a carrier-capable aircraft) flight-control system to be reprogrammed made the fix relatively easy. The worst problem, though, was the scarcity of internal fuel tankage.
One of the most important measures of a combat aircraft’s range is expressed by a number called the fuel fraction; that is, the weight of internal fuel expressed as a percentage of an aircraft’s takeoff weight. Normally, combat aircraft designers like to build aircraft with a fuel fraction of between .30 and .35. This gives enough gas to fly a decent distance, drop bombs or dogfight, and then return to the base or boat with a minimum of refueling from airborne tankers. In the design of the Hornet, the fuel fraction was woefully low. The origins of this problem dated from the original YF-17 design. That aircraft had been a technology demonstrator that did not require the kind of fuel load a combat aircraft would normally carry. Thus, the Northrop designers had not installed large internal fuselage tanks. In the process of “scaling up” the YF-17 into the Hornet, the MDC designers had failed to take this into account. For some reason that still defies explanation, the F/A-18 was given the same fuel fraction as the original YF-17—around .23. As a result, the Hornet would never be able to fly all of the missions that had been specified in the original VFAX requirement. For example, when operating in a bombing mode, the F/A-18 cannot possibly fly the same weapons loads as far as the A-7E Corsair, which it replaced.
The Hornet’s “short legs” came to light just as the Navy was about to make the production decision for the aircraft. It took more than a little hand-wringing and more than a few briefings to Navy, Marine, and Congressional leaders to make the case to put the F/A-18 into production. The NAVAIR rationalization was that since the aircraft had shown such good performance in so many other areas of flight test, the really-long-range-strike-mission requirement could be compromised. For example, the new APG-65 multi-mode radar was quickly hailed as one of the best in the world, and the weapons system integration made the Hornet an ordnance-delivery dream. Besides, the test and fleet pilots loved flying the new bird. They could see its potential, and were willing to accept a few shortcomings to get the Hornet into the fleet. So the decision to buy the first production batch of Hornets was made, and the first deliveries to VFA-125 at NAS Lemore, California, began in 1980. With this part of the story told, let’s take a closer look at the F/A-18.
At first glance, the Hornet looks very much like the F-14 (twin engines and tails), but the similarities are only superficial. The F/A-18 is more than a decade ahead of the Tomcat in technology. A sizable percentage of the Hornet’s structure, for example, is composed of plastics and composite structures. The twin General Electric F404-GE-400 engines utilize the same engine technology as the F110, and give the Hornet exceptional agility. Aerodynamically, the fixed wing of the F/A-18 is optimized for dogfighting, with six stations on the wings for ordnance (as well as AIM-9 Sidewinder AAMs on the wingtips). At the midpoint of each wing is a folding hinge, which allows the deck crews to reduce the “footprint” of the F/A-18 on the limited space of the flight and hangar decks. On the fuselage are two recessed wells for AIM-7 Sparrow and AIM-120 AMRAAM AAMs, as well as various types of sensor and data-link pods. There also is a centerline station suitable for a s
mall external fuel tank. The nose of the Hornet is a very busy place, with the APG-65 multi-mode radar mounted just ahead of a bay, which houses the M61 20mm Gatling gun. Normally, placing a vibration sensitive instrument like a radar close to a fire-spitting device like a cannon would be suicidal in an aircraft. Unfortunately, the F/A-18’s limited internal space gave MDC designers no choice. That this unlikely pairing of systems in the nose actually works speaks volumes about the care that designers gave every component of the Hornet.
The Navy has a real aversion to doing new things, and frequently prefers to let other services pioneer technology and ideas. However, for the F/A-18 to fulfill its missions, the Navy had to try some things that nobody had done before. One of these was to make the Hornet an effective dual-role (fighter and attack) aircraft, with only a single crewman. The only way to make this possible was to use an advanced cockpit design, a generation ahead of any used by any other combat aircraft. Like other fighters of its generation, the F/A-18 has a bubble canopy, with the pilot sitting with his/her shoulders above the cockpit rails in an ACES-series ejection seat, which provides the necessary “zero-zero” capability needed for safety in flight and deck operations. After that, the novelty begins.
To design the Hornet cockpit, MDC brought a unique talent to bear. Engineer Eugene Adam, acknowledged to be the finest cockpit designer in the world, led the MDC cockpit design team that produced the “front office” for the F/A-18. For years, Adam had advocated a “glass” cockpit, composed only of computer screens, which could be configured in any way desired by the pilot. With computer screens, a wide variety of data could be displayed at any time, depending upon what the pilot was doing at a given moment. Such a system was installed in the cockpit of the Hornet, which is made up of a series of square computerized Multi-Function Displays (MFDs) with buttons around the bezels that allow the pilot to select the data they want. To complement the MFDs, there were a second-generation HUD and HOTAS controls on the throttles and control stick. This made it possible for the pilot to switch from “Fighter” to “Attack” mode with just a flick of a switch. So advanced was the Hornet at the time of its introduction that it even included the first onboard GPS receiver seen in the fleet. These systems are backed up by one of the best avionics suites ever installed in a tactical aircraft.
The result was a cockpit still considered to be among the world’s finest. Perhaps best of all, it was a cockpit with room for improvements and upgrades. Soon, there will be a new helmet-mounted sighting system, which will allow the pilot to cue the radar and weapons-targeting systems by just looking at a target. The new AIM-9X version of the classic Sidewinder AAM will be the first to use this new feature.
Naval aviators love to tell me how much “fun” the Hornet is to fly, and this has had a positive effect on its image in the fleet. Pilots especially love the responsiveness of the FBW control system and the integrated “glass” cockpit. The F/A-18 can even land itself, using a system called “Mode-1” to automatically fly the bird to a perfect “OK-Three” landing. Maintenance personnel love it too, since its digital electronics are so reliable that aircraft are rarely down for equipment failures. There is a “down” side, though. Because of the F/A-18’s small internal fuel fraction, it almost always carries a pair of large fuel tanks under the wings, and frequently another one under the centerline of the fuselage. This leaves just four wing stations for actual weapons carriage. Since the two outer wing stations are load-limited (they are outboard of the wing fold line), these are usually reserved for additional AAMs, leaving just the two middle wing stations for carrying air-to-ground ordnance.52
If the Hornet is tasked for a bombing mission, the two fuselage stations will normally be filled with a single AIM-120 AMRAAM, and an AAS-38 Nighthawk FLIR/laser targeting pod. This configuration allows the F/A-18 to pick up targets in darkness or low visibility, and then deliver PGMs (like Paveway-series LGBs) or “iron” ordnance onto them with accuracy. Unlike the LANTIRN system used on the F-14, F-15, and F-16, Nighthawk (built by the Loral Division of Lockheed Martin) is designed to be operated by just a single crewman.57 This means that a Hornet driver can pick up a target using the Nighthawk FLIR, “lock” it up, and then trust the pod to automatically track the target and handle the release and delivery of the weapon. While early versions of the Nighthawk lacked the laser designator and had some reliability problems, the current version is doing a fine job in the fleet. More than any other piece of equipment, the Nighthawk pod has transformed the image of the F/A-18 around the world. Where once it was seen only as an “iron” bomber, now it carries a reputation for deadly precision.
A cutaway view of a Raytheon AGM-65 Maverick missile.
JACK RYAN ENTERPRISES, LTD., BY LAURA DENINNO
The Hornet can also employ other PGMs like the AGM-88 HARM antiradar missile, the AGM-65 Maverick tactical ASM, the AGM-84D Harpoon antishipping missile, and the new AGM-84E Standoff Land Attack Missile (SLAM).58 SLAM is a relative newcomer to the fleet, having first been introduced and employed during Desert Storm in 1991. Since that time, SLAM has seen action in Bosnia in 1995, and has become one of the finest standoff strike weapons in the world. What makes it such a winner is the use of the basic (and very dependable) AGM-84 Harpoon engine, airframe, and warhead package, which is now married to a new guidance and seeker package. This new system combines a GPS/INS unit, an imaging infrared (IIR) seeker head from an AGM-65 Maverick ASM, and a man-in-the-loop data-link unit from the old Walleye guided bomb.
The result is a weapon that achieved perhaps the most spectacular hit of Desert Storm. On its first combat “shot,” run against a heavily defended Iraqi weapons plant near Baghdad, two SLAMs were launched several minutes apart. The first missile, taking its basic guidance from the GPS/INS unit, flew to the target and locked up the desired aimpoint without difficulty. It then flew directly into the building wall, detonated, and made a very large hole. Several minutes later, the second SLAM flew through the hole created by the first missile and destroyed the equipment inside. Further success for the SLAM came during Operation Deliberate Force in Bosnia. The outstanding performance of SLAM has made it one of the most feared PGMs in the U.S. arsenal.
An AGM-84E SLAM missile being launched from an F/A-18C Hornet. SLAM was used during Operations Desert Storm and Deliberate Force, where it performed with amazing precision and lethality.
BOEING MILITARY SYSTEMS
In fleet service in its early years, the Hornet showed the shortcomings that had been seen in testing. While the F/A-18’s range limitations became obvious at once, for example, this could be improved simply by altering the altitude and speed (called the flight profile) that it flew during missions. Thus, the aircraft’s range could be stretched simply by flying it at higher altitudes, where the F404 engines were more efficient. Still, some of the Hornet’s original specifications would never be met, especially those of acceleration and range. Still, in the crucible of combat it passed the ultimate test. This first came in 1986, when a number of Hornet squadrons took part in operations against Libya. In ACM engagements against the MiGs and Mirages of the Libyan Air Force, the Hornets had no trouble staying on the tails of the opposing warplanes. They also helped suppress the Libyan air defenses with HARM missiles, another role they took over from the A-7E. The Hornet provided the Navy with one other pleasant surprise: its incredible reliability compared with other Navy aircraft like the F-14 and A-6. This meant that the Hornet was cheaper to operate, and could be flown more often than other comparable aircraft—so often, in fact, that the early F/A-18As wore out faster than expected, and had to be replaced earlier than planned. This led to an improved variant, the F/A-18C/D, which arrived in the fleet during 1986.
The -C/D model gained some weight over the -A/B Hornets, but unfortunately did not carry any more gas. The radar, avionics, engines, and other systems were significantly improved, however, including provisions to carry the AIM-120 AAM and IIR version of the AGM-65 Maverick ASM. The new Hornet also had a new-generation
monitoring system that allowed maintenance crews to diagnose problems automatically and even predict when individual components and “black boxes” might fail. There were also provisions for the new Hornet to be operated at night with night-vision goggles (NVGs), and a new radar: the APG-73 (planned for the new F/A-18E/F Super Hornet).
The F/A-18C/D was the Hornet that the Navy and Marines had wanted all along; and the Marine Corps bought six squadrons of modified -D models as night-attack aircraft to replace their force of retired A-6’s. The Hornet was also becoming something of a success in the export market. The first foreign customer was Canada, which bought 138 CF-18’s to conduct continental air defense as part of the North American Air Defense (NORAD) Command. Australia (seventy-five), Kuwait (forty), Spain (seventy-two), Switzerland (thirty-four), Finland (sixty-four), Thailand (eight), and Malaysia (eight) also bought various models of the F/A-18 to upgrade their air forces. All told, around 1,500 Hornets have been built to date.
By the time of the Iraqi invasion of Kuwait in 1990, the Hornet had been in service for almost a decade and was ready for its biggest combat challenge. Almost as soon as the U.S. began to react to the invasion, F/A-18 units were in the front lines of Desert Shield. Eventually, five carrier groups and an entire Marine Air Wing with Hornets as their backbone deployed into the theater. The Canadians also contributed a squadron of their CF-18’s to the effort. In Desert Storm the F/A-18 proved to be a deadly air-to-air killer. On January 17th, a pair of VF-81 Hornets from the USS Saratoga (CV-60) downed a pair of Iraqi F-7’s (Chinese MiG-21 clones) with a salvo of “in-your-face” AAM shots. The two F/A-18’s were loaded for a bombing mission at the time, but quickly switched to the air-to-air mode, shot down the enemy fighters, then went on to complete their bombing mission. The rest of the war was mainly spent delivering “iron” bombs onto battlefield targets in Kuwait and Iraq. In this mission, the success of the Hornets was something less than total.