The Super Rotor AC.4 Andorinha ("Swallow") was a sport autogyro first produced in Brazil in the 1960s. The prototype was built by Altair Coelho and flown in 1960 as the AC.1, a typically minimalist autogyro design consisting of an open framework supporting the pilot's seat, rotor mast, engine mounting and tail fin. Power was supplied by a converted Volkswagen engine driving a pusher propeller. Francisco Mattis purchased the prototype and manufacturing rights and founded Super Rotor (now Montalva) of São Paulo to produce the aircraft. Refinements for serial production as the AC.4 included an extra reinforcing strut for the rotor mast and a larger tail fin. According to Altair Coelho, the AC.4 first flew in 1964, and gained type approval and certification in 1972. 314 were built.
Super Rotor went on to produce a two-seat version with dual controls as the M.1 Montalva, a turbo-charged two-seater as the M.2 Trovão Azul ("Blue Thunder"), and an agricultural version with spray bars as the Agricóptero.