"The Diamondback is sort of like owning the sharpest knife in the world. It's an honest airplane, you know what's going on all the time. But like owning a sharp knife, you better not make any mistakes."
A F/A-25 Super Diamondback of VF-41 "Black Aces" prepares for take off for a peace time patrol from the USS JFK in 2056, a few years after WW3.
Designed by Northtrop Grumman in 2022 to replace the F-18E/F and supplement the Navy's F-35C's, the plane would spend over a decade in development. It likely would have gone on even longer if it were not for the NA War. The F-25A was rushed into service in 2032 and flaws immediately began to appear. The largest problem being the jets General Electric F135 engines which were prone to failure. The flight suit designed alongside the jet to help the pilot during high speed maneuvering also tended to fail. In the NA War, 1 in 2 F-25's built were destroyed.
Following the War, the Nationalist government and navy argued at great length as to what to arm the countries two remaining carriers (the other Nimitz and Ford class carriers were decommissioned as the country could no longer afford to run them) with. In the short run, the Progressive party won the debate, buying the cheaper surplus CF-205 Mk.I's from the Canadians. By 2040 though, intelligence believed that China and Russia's new J-23 and Su-54 respectively, outclassed the CF-205 Mk.I's in most categories. With the right wing Reformists now in power, they pushed to update and redesign the F-25's while also increasing funding for the fledgling XF-27 program. Over the course of the 2040's, several updates and variants were made. The culminating design came as the F/A-25D in 2048.
With the same engines as those used in the CF-205 Mk.IV, the Super D-Back was more reliable, and featuring a new internally designed radar, the Super D-back was more dangerous than its NA War era older sister. Being cheaper than the CF-205 Mk.VI, F/A-25's made became the main fighter aircraft of the RAAF and IAF, and even crossed from the Navy and into the US Marines and US Air Force.
Super D-Backs proved them self time and time again in WW3, having more aces than any other aircraft in the war and became the most produced allied fighter in the conflict. (regardless, the F-27A and CF-205 M.VI still garnered more fame).
In the post WW3 era, Super Diamondbacks are still used by the countries that used them in WW3, as well as Brazil, South China and the Philippines.