Development of a two-seat version of the Hornet was undertaken concurrently with than of the single-seater. Two examples of the TF-18A, later redesignated the F/A-18B, featured in the original contract. Basically similar to the single-seater, the F/A-18B possesses identical equipment and virtually identical combat capability. Procurement of the F/A-18B for the US Navy and USMC ended with the 40th example, and this version has never been employed by front-line forces.
The second two-seat version is the F/A-18D, which is broadly similar to the single-seat F/A-18C. F/A-18B/Ds serve with the US Navy's two principal Hornet training units, VFA-106 and VFA-125. F/A-18Bs also equip two reserve units, one of which (VFC-12) is an aggressor squadron. Some 31 baseline F/A-18Ds were built before production changed to the F/A-18D replaced the Grumman A-6 Intruder used by the USMC's all-weather attack squadrons; it equips six frontline units and a training squadron. Originally dubbed F/A-18D+, the aircraft features uncoupled cockpits, usually with no control column in the rear cockpit (although this item can be refitted) but two sidestick weapons controllers.
Marine Corps F/A-18Ds have served with distinction during combat operations, including Desert Storm in 1991 and Kosovo in 1999. Production of two-seat Hornets has also been undertaken for the export market, and all customers to date have ordered examples. Equipment and designations vary according to local requirements, but these machines are basically similar to their US service equivalents. Deliveries were undertaken to Australia (18 ATF-18As, essentially an F/A-18B), Canada (40 CF-18Bs for service with the local designation CF-188B), Kuwait (eight KAF-18Ds) and Spain (12 EF-18Bs, operated under the local designation CE.15).
The F/A-18D variant has been ordered by F/A-18C operators, these comprising Finland (seven) and Switzerland (eight). Malaysia has uniquely ordered only the two-seat variant in the form of eight F/A-18Ds. Thailand contracted for eight examples of the F/A-18C/D but later cancelled its order. Among options that can be specified by customers are APG-73 radar, -402 EPE powerplants and AIM-120 AMRAAM armament.