The Chengdu J-7 is a reverse-engineered Chinese copy of the ubiquitous MiG-21. Despite significant problems being encountered with early production of the aircraft, these were eventually resolved, and the type remains, numerically at least, one of the most important in service with the Chinese forces. This is one of the early J-7I variants, although its history and true identity are unconfirmed as it carries a serial that does not tie-in with any known Chinese serial blocks.