Naval Air: End Of The Line For Hornets

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March 29, 2023: Production of the American F-18 fighter will end in 2025, or a little later if the Indian Navy decides to adopt the F-18E for its aircraft carriers. There were two distinct models of the F-18; the F-18C and the later and larger F-18E. Both are twin-jet, single or two -seat jet fighters built to operate from aircraft carriers. The F-18 replaced about 1,200 of the 28-ton F-4 Phantom twin-jet two seat carrier aircraft as well as smaller numbers of specialized attack jets and even a few propeller aircraft. The F-4 entered carrier service in the 1960s and was used by the marines as well from carrier or land bases until replaced by F-18s in the 1980s.

There are actually two quite different aircraft that are called the F-18. In 1983 the A/B entered service followed by the improved C/D version in 1987. The E/F/G Super Hornet entered service in 2001. While the F-18E looks like the original F-18A, it is actually very different. The Super Hornets are about 25 percent larger (and heavier) than the earlier F-18s and use a new, more powerful engine. By calling the Super Hornet an upgrade, it was easier for the navy to get the money from Congress. That's because, in the early 1990s, Congress was expecting a "peace dividend" from the end of the Cold War, and was slashing the defense budget. There were a lot of commonalities between the two F-18s, but they are basically two different aircraft. When used more heavily than expected, they developed metal fatigue in different parts of the airframe.

The U.S. Navy retired its F-18C Hornet fighters in 2019. Some will still be flown by reserve units to represent enemy aircraft during “adversary training.” The U.S. Marines will continue to use their F-18Cs until at least 2030 and so will most foreign users. The F-18 A/B/C/D was in production from 1974 to 2000 with 1,480 built. The most widely used (75 percent) model was the single-seat F-18C. Some F-18Cs were built with two seats for training or complex missions. Some of those were later modified with the back seat replaced by special electronics gear. With the widespread use of smart bombs and guided missiles by 2000, there was no longer a need for a two seat “attack” version of the F-18. A single pilot could handle use of guided bombs and do so from a higher (safe from a lot of anti-aircraft fire) altitude.

The U.S. Navy was the first and largest F-18 user. Currently the navy has 31o single-seat F-18Es, 246 two-seat F-18Fs and 161 EA-18Gs. While the navy and marines operated about 60 percent of F-18Cs and F-18Es, these two aircraft types, particularly the F-18C, were purchased by export customers Australia, Canada, Finland, Kuwait, Malaysia, Spain and Switzerland. These nations are phasing out the F-18C or seeking a replacement. Australia sold 25 of its retired F-18Cs to Canada, which is switching to F-35s. This process won’t be complete until the 2030s. Australia, like many other F-18C users, also adopted the F-35.

The U.S. navy and marines are eventually replacing all their F-18s and Harriers with F-35s. The F-18 that will probably serve the longest is the F-18G electronic warfare aircraft, which is based on the two-seat F-18F, entered service in 2008 and so far 175 are in service. The F-18G is still in production, and that is not expected to end until the late 2020s or 2030. The electronic warfare aspect of the 18G demands a two seat aircraft, with the GIB (Guy in Back) taking care of all the sensors, jammers and other specialized electronics.

The navy began to realize, about a decade ago, that their F-18Cs would have to be retired earlier than expected. This was confirmed in 2010 when the navy grounded 16 percent (104 of 635) of its older (A/B/C/D models) F-18s. The reason was the discovery of cracks in the airframe. Small cracks were expected to show up eventually, the result of all the stress put on the metal from violent aerial maneuvers and carrier landings. In this case, the cracks were showing up sooner than expected. Most of the grounded aircraft could still be flown in an emergency. All these older F-18s had to be examined, and, for those found with cracks (usually where the wing meets the fuselage), temporary repairs could be made.

Since about 2006 the navy found that both their older F-18C Hornet fighters and their 640 newer F-18E Super Hornets were wearing out faster than expected. This was sort of expected with the F-18Cs, which entered service in the 1980s. These aircraft were expected to last about twenty years. But that was based on a peacetime tempo of operations, with about a hundred carrier landings (which is hard on the airframe) per year. There have been more than that because of the 1991 Gulf War (and the subsequent decade of patrolling the no-fly zone) and the war on terror. To keep enough of these aircraft operational until the F-35 arrives to replace them, new structural components (mainly the center barrel sections) were manufactured. This is good news for foreign users of the F-18C, who want to keep their aircraft in service longer.

The F-18E entered service in 2001 and was supposed to last 6,000 flight hours. Unexpectedly, the portion of the wing that supports the pylons holding stuff (bombs, missiles, equipment pods or extra fuel tanks) was found to be good for no more than 3,000 flight hours. The metal, in effect, weakened faster than expected. Metal fatigue, which ultimately results in the metal breaking, is normal for all aircraft. Calculating the life of such parts is still part art, as well as a lot of science. Unexpectedly high combat operations are the culprit. One specific reason for the problem was the larger than expected number of carrier landings carrying bombs. That's because so many missions flown over Iraq and Afghanistan did not require F-18Es to use their bombs or missiles.

The navy modified existing F-18Es to fix the problem, which is a normal response to such situations. Sometimes these fixes cost millions of dollars per aircraft, but this particular fatigue problem is costing more to fix than expected. Many aircraft were beyond repair and had to be retired. The F=35C began replacing F-18s on carriers in 2019 and it will take most of the 2020s before there are enough F-35Cs to replace all the F-18s. About a hundred F-18s went to export customers and most of these were operated from land bases. Many of these F-18s are expected to remain in service until 2040.