During the early 1970's the United States Air Force was busy reviewing the potential of a lightwheight fighter (LWF). Airforce brass were unsure of whether or not to actually buy any, but merely wished to research the potential of such an aircraft flying useful missions. After some degree of R&D, two different types of LWF participated in a fly-off competition. One of these two planes was the YF-17.

In 1974 Congressional approval was granted to the United States Navy to study a VFAX(fixed-wing fighter attack experimental) in a similar exercise. The NAVY wanted to study the VFAX because of concern over the high price of the capable F-14 TOMCAT, and thus, wanted to see if a cheaper aircraft could be built to replace the F-4 PHANTOM in the figher role, and the A-7 CORSAIR in the attack role.

Although such an aircraft could have been designed, Congress terminated the VFAX programme in 1974, and instructed the NAVY that instead they should investigate suitably adapted versions of the US Air Force LWF prototypes. This Congressional intervention could have easily led to a very disasterous situation, like that of the NAVY's attempt to build a NAVY fighter version of the Air Force F-111 during the 1960's.

After the COngressional ruling, McDonnell Douglas began to execute a careful evaluation of the YF-17(The Air Force LWF). After the examination, it was concluded that the YF-17 could be redesigned to meet the NAVY's specific requirements. Although the redesigned exterior look like it had hardly been touched, inside it was very different.

One of the biggest, and most notable inovations was to widen the fuselage by cutting it down the center, and splicing in an extra section. This improvement roughly doubled the internal fuel capacity, but also caused the engineers to increase the wing area to compensate for the extra weight. This new combination of increased weight and suitability for the NAVY's carrier operation required a completely redesigned landing gear of greatly increased strength. The new landing gear also incorporated a twin-wheel nose gear(because of the tricycle type design) complete with a catapult towbar. Also, the main gear were strange new devices that carried the wheels on a pivoting arm that would hang, ungainly, downwards on the approach, then rotate backwards as the aircraft touched down.

The wider fuselage also made it easier to fit in a multimode radar in the enlarged nose. At the rear, the enlarged engine bays, originally made for the 15,000-lb GE Yj101 bypass turbojets were made slightly bigger to acommodate 16,000-lb F404 turbofans, also made by General Electric. The designers also had to arrange the wing to fold, and add a tail hook. Later, the horizontal stabalizers were reconfigured slightly for improved performance.

Although the origianl idea was to design an F-18 fighter version and an A-18 attack version, it was decided to biuld a multi-role F/A-18 because the differences between the two versions were so minor.

After reaching a teaming aggreement with Northrup to share the workload, and the products, the first Hornet rolled off the McDonnell Douglas St. Louis plant lines on September 13, 1978, and was test flown by Jack Krings, on November 18.