The Hispano HS-42 and its derivative, the HA-43, were advanced military trainer aircraft produced in Spain in the 1940s. The basic design was that of a conventional, low-wing, cantilever monoplane with seating for the pilot and instructor in tandem. The HS-42 had fixed, tailwheel undercarriage with spatted mainwheels, while the HA-43 had retractable main units. Produced on the assembly line that had been used to build Fokker D.XXI fighters, the HS-42 shared some components with this aircraft.