The F/A-18C is the single-seat variant and the F/A-18D is the two seat variant. The D-model can be configured for training or as an all-weather strike craft. The "missionized" D-model's rear seat is configured for a Weapons and Sensors Officer to assist in operating the weapons systems. The F/A-18D 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 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 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 NITE Hawk FLIR (forward looking infrared array) targeting pod, night vision goggles, and two full-color (previously monochrome) MFDs and a color moving map.
In addition, 60 D-model Hornets are configured as the night attack F/A-18D (RC) with ability for reconnaissance. These could be outfitted with the ATARS electro-optical sensor package that includes a sensor pod and equipment mounted in the place of the M61 cannon.
Beginning in 1992, the F404-GE-402 enhanced performance engine, providing approximately 10% more maximum static thrust became the standard Hornet engine. Since 1993, the AAS-38A NITE Hawk added a designator/ranger laser, allowing it to self-mark targets. The later AAS-38B added the ability to strike targets designated by lasers from other aircraft.