F/A-18 Hornet

F/A-18 in flight
Type Multirole fighter
Manufacturer McDonnell Douglas/Boeing
Northrop
Designed by McDonnell Douglas
Maiden flight 18 November 1978
Introduction 7 January 1983
Primary users United States Navy
United States Marine Corps
Royal Australian Air Force
Spanish Air Force
Number built >1,458
Unit cost US$35 million in 2003
Developed from Northrop YF-17
Variants CF-18 Hornet
F/A-18E/F Super Hornet
EA-18 Growler
The McDonnell Douglas (now Boeing) F/A-18 Hornet is a modern all-weather carrier-capable strike fighter jet, designed to attack both ground and aerial targets. Designed in the 1970s for service with the U.S. Navy and U.S. Marine Corps, the Hornet is also used by the air forces of several other nations. It has been the aerial demonstration aircraft for the Blue Angels since 1986. Its primary missions are fighter escort, fleet air defense, suppression of enemy air defenses (SEAD), interdiction, close air support and reconnaissance. Its versatility and reliability have proven it to be a valuable carrier asset, though it has been criticized for its lack of range and payload compared to its contemporaries.[1] The Hornet has also been exported to several nations worldwide.

The F/A-18E/F Super Hornet is a distinct, evolutionary upgrade to the F/A-18 designed to serve a complementary role with Hornets in the U.S. Navy.[2]
[edit] Development
Development of the F/A-18 came as a result of the U.S. Navy's Naval Fighter-Attack, Experimental (VFAX) program to procure a multirole aircraft to replace the F-4 Phantom II, A-4 Skyhawk, and A-7 Corsair II, and to complement the F-14 Tomcat. Vice Admiral Kent Lee, then head of Naval Air Systems Command (NAVAIR), was the lead advocate for the VFAX against strong opposition from many Navy officers, including Vice Admiral William D. Houser, deputy chief of naval operations for air warfare - the highest ranking naval aviator.[3] In August 1973, congress mandated that the Navy pursue a lower-cost alternative to the F-14. Grumman proposed a stripped F-14 designated the F-14X, while McDonnell Douglas proposed a navalized F-15, but both were nearly as expensive as the F-14. That summer, Secretary of Defense Schlesinger ordered the Navy to evaluate the competitors in the Air Force's Light Weight Fighter (LWF) program, the General Dynamics YF-16 and Northrop YF-17.[4] Though the competition specified a day fighter with no strike capability. In May 1974, the House Armed Services Committee redirected $34 million from the VFAX to a new program, the Navy Air Combat Fighter (NACF),[4] intended to make maximum use of the technology developed for the LWF program.[5]


The YF-17 Cobra was navalized and developed into the F/A-18.Though the YF-16 won the LWF competition, the Navy was skeptical that an aircraft with one engine and narrow landing gear could be easily or economically adapted to carrier service, and refused to adopt an F-16 derivative. The Navy fought for and won permission to develop an aircraft based on the YF-17. Since the LWF did not share the design requirements of the VFAX, the Navy asked McDonnell Douglas and Northrop to design a new aircraft around the configuration and design principles of the YF-17. The new aircraft, designated the F-18, shared not a single essential dimension or primary structure with the YF-17. Secretary of the Navy W. Graham Claytor announced on 1 March 1977 that the name of the aircraft would be "Hornet".[5]


F/A-18 attached to catapult on the flight deck of USS Abraham Lincoln.Northrop had enlisted the aid of McDonnell Douglas as a secondary contractor on the NACF proposal to capitalize on the latter's extensive experience in building carrier aircraft, including the highly successful F-4 Phantom II. On the F-18, the two companies agreed to split the parts manufacture evenly, with McDonnell Douglas completing the final assembly, representing ~20% of the work. McDonnell Douglas built the wings, stabilators, and forward fuselage; Northrop built the center and aft fuselage and vertical stabilizers. McDonnell Douglas was the prime contractor for the naval versions.[4] Northrop would become the prime contractor and take over final assembly for the F-18L land-based version which Northrop hoped to sell on the export market.

The F-18, initially known as McDonnell Douglas Model 267, was drastically modified from the YF-17 while retaining the same basic configuration. For carrier operations, the airframe, undercarriage, and arrestor hook were strengthened, folding wings and catapult attachments were added, and the landing gear widened. To meet Navy range and reserves requirements, McDonnell increased fuel capacity by 4,460 pounds, with the enlargement of the dorsal spine and the addition of a 96 gallon fuel cell to each wing (the YF-17 had dry wings). Most visibly, a "snag" was added to the leading edge of the wings and stabilators to prevent a flutter discovered in the F-15 stabilator. The wings and stabilators were enlarged, the aft fuselage widened by 4 inches, and the engines canted outward at the front. These changes added 10,000 pounds to the gross weight, bringing it to 37,000 lb. The computer-assisted control system of the YF-17 was replaced with a wholly digital fly-by-wire system, the first to be installed in a production fighter.

The original plan specified acquiring 780 total of three closely related models: the single seat F-18A fighter and A-18A attack aircraft, differing only in avionics, and the dual-seat TF-18A, which retained full mission capability of the F-18,[1] except with a reduced fuel load. With redesign of the stores stations and improvements in avionics and multifunction displays, it became possible to combine the A-18A and F-18A into one aircraft.[5] Starting in 1980, the aircraft began being referred to as the F/A-18A, and the designation was officially announced on 1 April 1984. The TF-18A was redesignated F/A-18B.[5][1]


[edit] Northrop's F-18L
Northrop developed the F-18L as a potential export aircraft. Since it did not have to be strengthened for carrier service, it was expected to be lighter and better performing, and a strong competitor to the F-16 Fighting Falcon then being offered to American allies. The F-18L was 7,700 pounds (3,493 kg) (approximately 30%) lighter than the F/A-18A, due to a lighter landing gear, removal of the wing folding mechanism, and reduced frame thickness in some areas. Though the aircraft retained a lightened arresting hook. The most obvious external difference was the removal of the "snags" on the leading edge of the wings and stabilators. It still retained 71% commonality with the F/A-18 by parts weight, and 90% of the high-value systems, including the avionics, radar, and ECM suite, though alternatives were offered. Unlike the F/A-18, the F-18L carries no fuel in its wings and lacked weapons stations on the intakes. It had three underwing pylons on each side instead.

The partnership between the McDonnell Douglas and Northrop soured over competition for foreign sales for the two models. Northrop felt that McDonnell Douglas would put the F/A-18 in direct competition with the F-18L. In October 1979, Northrop filed a series of lawsuits charging that McDonnell was using Northrop technology developed for the F-18L for foreign sales in violation of their agreement, and asked for a moratorium on foreign sales of the Hornet via McDonnell Douglas. The case was resolved in 1985 when McDonnell agreed to pay Northrop $50 million for complete rights to the design, without any admission of wrongdoing. By then Northrop had ceased work on the F-18L, and most export orders were captured by the F-16 or the F/A-18.[5]


[edit] Design

A Hornet is doing a high-g pull-up during an air show. The high angle of attack causes powerful wingtip vortices to form at the leading edge extensions. The vortices shown are so powerful that the drop in pressure experienced at their center results in visible vapor formations from water precipitating in the air, sometimes called "vapes".The F/A-18 is a twin engine, mid-wing, multi-mission tactical aircraft. It is superbly maneuverable, owing to its good thrust to weight ratio, digital fly-by-wire control system, and leading edge extensions (LEX). The LEX allow the Hornet to remain controllable at high angles of attack. This is because the LEX produce powerful vortices over the wings, creating turbulent airflow over the wings and thus delaying or eliminating the aerodynamic separation responsible for stall, allowing the Hornet's wings to generate lift several times the aircraft's weight, despite high angles of attack. The Hornet is therefore capable of extremely tight turns over a large range of speeds.

Canted vertical stabilizers are another distinguishing design element, and among the other design characteristics that enable the Hornet's excellent high angle-of-attack capability include oversized horizontal stabilators, oversized trailing edge flaps that operate as flaperons, large full-length leading-edge flaps, and flight control computer programming that multiplies the movement of each control surface at low speeds and moves the vertical rudders inboard instead of simply left and right. The Hornet's normally high angle-of-attack performance envelope was put to rigorous testing and enhanced in the NASA F-18 HARV. NASA used the F-18 HARV to flight-validate high angle-of-attack handling qualities that had not been done previously because of the difficulty in performing such tests in a safe and methodical manner. The F/A-18's stabilators were used as canards on NASA's F-15S/MTD.

The Hornet was among the first aircraft to heavily utilize multi-function displays, which at the switch of a button allow the pilot to perform either fighter or attack roles or both. This "force multiplier" capability gives the operational commander more flexibility in employing tactical aircraft in a rapidly changing battle scenario. It was the first Navy aircraft to incorporate a digital multiplex avionics bus, enabling easy upgrades.[1]

The Hornet is also notable for having been designed with maintenance in mind, and as a result has required far less downtime than its counterparts, the F-14 Tomcat and the A-6 Intruder. Its mean time between failure is three times greater than any other Navy strike aircraft, and requires half the maintenance time.[1] For example, whereas replacing the engine on the A-4 Skyhawk required removing the aircraft's tail, the engine on the Hornet is attached at only three points and can be directly removed without excessive disassembly.


F/A-18 Hornet in transonic flight (Note Prandtl-Glauert condensation).The General Electric F404-GE-400 or F404-GE-402 engines powering the Hornet were also innovative in that they were designed with operability, reliability, and maintainability first. The result is an engine that, while unexceptional on paper in terms of rated performance, demonstrates exceptional robustness under a variety of conditions and is resistant to stall and flameout. By contrast, the Pratt & Whitney TF30 engines that originally powered the F-14A were notoriously prone to flameout under certain flight conditions.

The engine air inlets of the Hornet, like that of the F-16, are "fixed", while those of the F-4, F-14, and F-15 have variable geometry or variable ramp engine air inlets. The variable geometry enables high-speed aircraft to keep the velocity of the air reaching the engine below supersonic. This is one speed limiting factor in the Hornet design. Instead, the Hornet uses bleed air vents on the inboard surface of the engine air intake ducts to slow and reduce the amount of air reaching the engine. While not as effective as variable geometry, the bleed air technique functions well enough to achieve near Mach 2 speeds, which is within the designed mission requirements. The less sophisticated design is also more robust.

Because it was designed as a light multirole aircraft to complement the specialized F-14 and A-6 airframes, it had a relatively low internal fuel fraction. That is, its internal fuel capacity is small relative to its take-off weight, at around 23%. Most aircraft of its class has a fuel fraction between .30 to .35. This situation was exacerbated by the addition of new avionics over its lifespan, further reducing the fuel fraction.


[edit] Design evolution
In the 1990s the US Navy faced the need to replace its aging A-6 Intruders, EA-6 Prowlers, A-7 Corsair IIs and F-14 Tomcats without proper replacements in development. To answer this deficiency, the Navy had the F/A-18E/F Super Hornet developed. Despite its designation, it is not an upgrade of the F/A-18 Hornet, but rather, a new, larger airframe utilizing the design concepts of the Hornet. Until the deployment of the F-35C Lightning II, Hornets and Super Hornets will serve complementary roles in the US Navy carrier arsenal.


[edit] Operational history

[edit] Entry into service

F/A 18 Hornets on the flight deck of the Nimitz-class supercarrier Harry S. TrumanMcDonnell Douglas rolled out the first F/A-18A on 13 September 1978,[6] in blue-on-white colors marked with "Navy" on the left and "Marines" on the right. Its first flight was on 18 November.[6] In a break with tradition, the Navy pioneered the "principal site concept"[4] with the F/A-18, where almost all testing was done at NAS Pax River,[1] instead of near the site of manufacture, and involving Navy test pilots instead of contractor pilots much earlier in the process.

In March 1979, Lt Cdr John Padgett became the first Navy pilot to fly the F/A-18. In all, nine F/A-18As and two F/A-18Bs were assigned to flight systems development. During this period, the snag on the leading edge of the stabilators was filled in, and the gap between the leading edge root extendors (LERX) and the fuselage mostly filled in. The gap, called the boundary layer air discharge (BLAD) slots, controlled the vortices generated by the LERX and presented clean air to the vertical stabilizers at high angles of attack. However, they also generated a great deal of parasitic drag, worsening the problem of the F/A-18's inadequate range. McDonnell filled in 80% of the gap, leaving a small slot to bleed air from the engine intake. This may have contributed to early problems with fatigue cracks appearing on the vertical stabilizers due to extreme aerodynamic loads, resulting in a momentary grounding in 1984 until the stabilizers were strengthened. Starting in May 1988, a small vertical fence was added to the top of each LEX to broaden the vortices and direct them away from the vertical stabilizers. This also provided a minor increase in controllability as a side effect.


An F/A-18 taking off from USS Kitty Hawk.The first production F/A-18A flew on 12 April 1980, and following trials by VX-4 and VX-5, began to fill the Fleet Readiness Squadrons (FRS) VFA-125, VFA-106, and VMFAT-101, where pilots are introduced to the F/A-18. the Hornet entered operational service with Marine Corps squadron VMFA-314 at MCAS El Toro on 7 January 1983,[6] and with Navy squadron VFA-113 in March 1983, replacing F-4s and A-7Es, respectively.[1] The initial fleet reports were complimentary, indicating that the Hornet was extraordinarily reliable, a major change from its predecessor, the F-4J.[5] Other squadrons that switched to F/A-18 are VFA-146 "Blue diamonds", and VFA-147 "Argonauts".

After a production run of 380 F/A-18As[6] (including the nine assigned to flight systems development), manufacture shifted to the F/A-18C in September 1987.[1] As the A-6 Intruder was retired in the 1990s, its role was filled by the F/A-18. The F/A-18 demonstrated its versatility and reliability during Operation Desert Storm, shooting down enemy fighters and subsequently bombing enemy targets with the same aircraft on the same mission, and breaking all records for tactical aircraft in availability, reliability, and maintainability. The aircraft's survivability was proven by Hornets taking direct hits from surface-to-air missiles, recovering successfully, being repaired quickly, and flying again the next day.


[edit] Combat service
The F/A-18 first saw combat action in April 1986, when Hornets from Coral Sea flew SEAD missions against Libyan air defenses during Operation Prairie Fire and an attack on Benghazi as part of Operation El Dorado Canyon.[5]

Two US Navy F/A-18s were lost in the first hours of the Gulf War in 1990. One of the pilots, Lt Robert Dwayer was killed although the cause of his loss is unclear. The other, Lt Cdr M. Scott Speicher (VFA-81) remains missing in action. There are conflicting government accounts of Speicher's downing. One source, an unclassified summary of a 2001 CIA report, states that Speicher's aircraft was destroyed by an air-to-air missile fired by an Iraqi fighter, and that he may have survived by ejecting.[7] F/A-18 pilots were credited with two kills during the Gulf War, both MiG-21s.[8]

On the first day of Operation Desert Storm (17 January 1991), U.S. Navy pilots Lt. Nick Mongilio and Lt. Cmdr. Mark Fox were sent from the USS Saratoga in the Red Sea to bomb an airfield in southwestern Iraq. While enroute they were warned by E-2 of approaching MiG-21 aircraft. The Hornets shot down two MiGs and resumed their bombing run, each carrying four 2,000lb bombs, before returning to Saratoga. Mongilio and Fox become the first pilots to register air-to-air kills while still completing their original air-to-ground mission.[6][1]

Both U.S. Navy F/A-18Cs and Marine F/A-18A/C/D models were used continuously in Operation Southern Watch and over Bosnia and Kosovo in the 1990s. U.S. Navy Hornets flew in Operation Enduring Freedom from carriers operating in the North Arabian Sea. Both the F/A-18C and newer F/A-18E/F variants were used in Operation Iraqi Freedom. A F/A-18C was accidentally downed in a Friendly Fire incident by a Patriot missile early in the conflict, and two others collided over Iraq in May 2005.


[edit] Variants

[edit] A+/C/D

A Finnish Air Force F/A-18C at RIAT 2005The F/A-18A and F/A-18C are single-seat aircraft. The F/A-18B and F/A-18D have two seats, space for the rear cockpit being provided by a relocation of avionic equipment and a 6% reduction in internal fuel; two-seat Hornets are otherwise fully combat-capable. The B model is used primarily for training, while the D model is configured as an all-weather strike craft. Whereas the B model has both seats configured as pilot's stations, the D model's rear seat is configured for a Weapons and Sensors Officer to assist in operating the weapons systems. The D model is primarily operated by the U.S. Marine Corps in the night attack and FAC(A) (Forward Air Controller (Airborne)) roles.

The F/A-18C and D models are the result of a block upgrade in 1987[6] incorporating upgraded radar, avionics, and the capacity to carry new missiles such as the AIM-120 AMRAAM air-to-air missile and AGM-65 Maverick[1] and AGM-84 Harpoon air-to-surface missiles. Other upgrades include the Martin-Baker NACES (Navy Aircrew Common Ejection Seat), and a self-protection jammer. A synthetic aperture ground mapping radar enables the pilot to locate targets in poor visibility conditions. C and D models delivered since 1989 also include an improved night attack capability, consisting of the Hughes AN/AAR-50 thermal navigation pod, the Loral AN/AAS-38 Night Hawk FLIR (forward looking infrared array) targeting pod, night vision goggles, and two full-color (previously monochrome) MFDs and a color moving map.[1]


The Blue Angels' F/A-18A.The F/A-18A and B models are used by the US Navy's Blue Angels aerobatic team, performing at airshows and other special events across the US and worldwide. The Blue Angels have used the Hornet since 1986[6] when it replaced the A-4 Skyhawk. The two-seat B model is typically used to give rides to VIPs, but can also fill in for other aircraft in the squadron in a normal show if the need arises.

Beginning in 1991, Hornets were upgraded to the F404-GE-402 engine, providing a 20% increase in thrust.

In 1992, the original Hughes AN/APG-65 radar was replaced with the Hughes (now Raytheon) AN/APG-73, a faster and more capable radar. The A model Hornets upgraded to the AN/APG-73 are designated F/A-18A+. Since 1993, the Nite Hawk also has a designator/ranger laser, allowing it to self-mark targets.

In addition, 48 D model Hornets are configured for reconnaissance as the F/A-18D (RC) version, substituting the gun with an electro-optical sensor package call ATARS.

Production of the F/A-18C ended in 1999.


[edit] E/F Super Hornet
Main article: F/A-18E/F Super Hornet

A VFA-11 F/A-18F Super Hornet performing evasive maneuvers during an air power demonstration above USS Harry S. Truman.The single seat F/A-18E and two-seat F/A-18F Super Hornets carry over the name and design concept of the original F/A-18, but have been extensively redesigned. The Super Hornet has a new, 25% larger airframe, more powerful GE F414 engines based on F/A-18's F404, and upgraded avionics suite. The aircraft is currently in production and will eventually equip 22 squadrons.


[edit] EA-18G Growler
Main article: EA-18 Growler
The EA-18G Growler is an electronic warfare version of the F/A-18F Super Hornet, slated to begin production in 2008, with fleet deployment in 2009. The EA-18G will replace the Navy's EA-6B Prowler.


[edit] Other U.S. variants

X-53, NASA's modified F/A-18.RF-18
This designation was given to a reconnaissance version of the F/A-18A. The first of two prototypes flew in February 1984, however the variant was not produced.
TF-18A
Two-seat training version of the F/A-18A fighter, later redesignated F/A-18B.
F-18D(CR)
Proposed two-seat reconnaissance version for the US Marine Corps. The F-18D(CR) was originally intended to replace the RF-4B Phantom II tactical reconnaissance aircraft. None were ever built.
F-18 HARV
Single-seat high-alpha research vehicle for NASA.
X-53 Active Aeroelastic Wing
A NASA F/A-18 has been modified to demonstrate the Active Aeroelastic Wing technology, and was designated X-53 in December 2006.

[edit] Export variants
These designations are not part of 1962 United States Tri-Service aircraft designation system.

F-18L
This was a lighter land-based version of the F/A-18 Hornet. It was designed to be a single-seat air-superiority fighter and ground-attack aircraft. It was originally intended to be built by Northrop as the export version of the F/A-18 Hornet. The F-18L was lighter due to the removal of carrier landing capability. Despite the advantages, customers preferred the "ordinary" Hornet, and the F-18L never went into production.
(A)F/A-18A/B

(A)F/A-18A: Single-seat fighter/attack version for the Royal Australian Air Force.
(A)F/A-18B: Two-seat training version for the Royal Australian Air Force.
"F/A-18A" was the original company designation, designations of "AF-18A" & "ATF-18A" have also been applied. Assembled in Australia (excluding the first two (A)F/A-18Bs) by Aero-Space Technologies of Australia (ASTA) from 1985 through to 1990, from kits produced by McDonnell Douglas with increasing local content in the later aircraft. Originally the most notable differences between a Australian (A)F/A-18A/B and a US F/A-18A/B were the lack of a catapult attachment, replacement of the carrier tailhook for a lighter "land" arresting hook, and the replacement of the automatic carrier landing system with an Instrument Landing System. Australian Hornets have been involved in a number of major upgrade programs. This program called HUG (Hornet Upgrade) has had a few evolutions over the years. The first was to give Australian Hornets F/A-18C model avionics. The second and current upgrade program (HUG 2.2) updates the fleet's avionics to beyond E model Hornet capability.


Canadian CF-18A Hornet off the coast of Hawaii. Note the 'false cockpit' painted on the underside of the aircraft, intended to confuse enemy pilots during dogfights.CF-18 Hornet

CF-18A : Single-seat fighter/attack version for the Canadian Forces. The Canadian Forces' official designation is CF-188A Hornet.
CF-18B : Two-seat training version for the Canadian Forces. The Canadian Forces' official designation is CF-188B Hornet.
EF-18 Hornet

EF-18A: Single-seat fighter/attack version for the Spanish Air Force. The Spanish Air Force designation is C.15.
EF-18B: Two-seat training version for the Spanish Air Force. The Spanish Air Force designation is CE.15.
KAF-18 Hornet

KAF-18C: Single-seat fighter/attack version for the Kuwait Air Force.
KAF-18D: Two-seat training version for the Kuwait Air Force.
F-18C/D Hornet

Finland uses F/A-18C/D Hornets, with Finland specific mid-life update. It lacks certain avionics, target acquisition and weapon control features, limiting its ground attack capability. The 57 single-seated F-18C model units were assembled by Patria in Finland.[9]
F-18C/D Hornet

Switzerland uses F-18C/D,[10] later Swiss specific mid-life update. The Swiss F-18s were originally without ground attack capability until hardware was retrofitted.