The Pilatus PC-9 is a more powerful evolution of the plane that more than 20 air forces now use as their what?
Pilatus PC-9:  Designed as a more powerful evolution of the Pilatus PC-7, the PC-9's first flight was made in May 1984 after which certification was achieved in September 1985. Pilatus PC-7:  It has been selected by more than 20 air forces as their ab initio trainer.
ab initio trainer