Question: The monoplane called Pucara, was used  by what?

Context paragraphs:
Pitts Special (monoplane): Pitts built a monoplane racer Special in the early postwar years.  Pitts also built several monoplane racing planes in the 1940s–1950s, the most famous of which was the low-winged "Pellet" of 1947 and the mid-winged Special "Lil' Monster" & "Miss Dayton" of 1951.  Among other one-off projects, he also built a two-seat sport monoplane called the "Big Hickey".

FMA IA 58 Pucará: The FMA IA 58 Pucará (Quechua: "Fortress" ) is an Argentine ground-attack and counter-insurgency (COIN) aircraft manufactured by the Fábrica Militar de Aviones.  It is a low-wing twin-turboprop all-metal monoplane with retractable landing gear, capable of operating from unprepared strips when operationally required.  The type saw action during the Falklands War and the Sri Lankan Civil War.

Charles Horace Watkins: Charles Horace Watkins (1884–1976) was an aviation pioneer who built the first engine-powered aeroplane in Wales, a red monoplane called the "Robin Goch".

Raid on Pebble Island: The Raid on Pebble Island was a raid by British Special Forces on Pebble Island's airfield during the Falklands War, and took place on the night of 14–15 May 1982.  Pebble Island is one of the smaller Falkland Islands, lying north of West Falkland.  The site was being used as a forward operating base for T-34 Mentor and Pucara aircraft by the Argentine Air Force; British Special Air Service (SAS) operatives were tasked with destroying the aircraft on the ground, in an operation that echoed back to some of the unit's first missions during the North African Campaign of World War II.

Gnome Omega: The Gnome 7 Omega (commonly called the Gnome 50 hp) is a French seven-cylinder, air-cooled aero engine produced by Gnome et Rhône.  It was shown at the Paris Aero Salon held in December 1908 and was first flown in 1909.  It was the world's first aviation rotary engine produced in quantity.  Its introduction revolutionized the aviation industry and it was used by many early aircraft.  It produced 50 horsepower (37 kW) from its capacity of 8 litres (488 cubic inches).  A Gnome Omega engine powers the 1912 Blackburn Monoplane, owned and operated by the Shuttleworth Collection, the oldest known airworthy British-designed aeroplane worldwide.  A two-row version of the same engine was also produced, known as the Gnome 14 Omega-Omega or Gnome 100 hp.  The prototype Omega engine still exists, and is on display at the United States' National Air and Space Museum.

Supporting paragraphs: Raid on Pebble Island FMA IA 58 Pucará
Answer: Argentine Air Force